restructuring

F1:F103/BMP180/BMP180.c

@@ -0,0 +1,280 @@
+/*
+ * This file is part of the BMP180 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "i2c.h"
+#include "BMP180.h"
+
+//#define EBUG
+
+#ifdef EBUG
+#include "usb.h"
+#include "proto.h"
+#define DBG(x)  do{USB_send(x);}while(0)
+#else
+#define DBG(x)
+#endif
+
+#define BMP180_I2C_ADDRESS     (0x77)
+/**
+ * BMP180 registers
+ */
+#define BMP180_REG_OXLSB        (0xF8)
+#define BMP180_REG_OLSB         (0xF7)
+#define BMP180_REG_OMSB         (0xF6)
+#define BMP180_REG_OUT          (BMP180_REG_OMSB)
+#define BMP180_REG_CTRLMEAS     (0xF4)
+#define BMP180_REG_SOFTRESET    (0xE0)
+#define BMP180_REG_ID           (0xD0)
+#define BMP180_REG_CALIB        (0xAA)
+
+// shift for oversampling
+#define BMP180_CTRLM_OSS_SHIFT  (6)
+// start measurement
+#define BMP180_CTRLM_SCO        (1<<5)
+// write it to BMP180_REG_SOFTRESET for soft reset
+#define BMP180_SOFTRESET_VAL    (0xB6)
+// start measurement of T/P
+#define BMP180_READ_T           (0x0E)
+#define BMP180_READ_P           (0x14)
+
+// delays in milliseconds
+//#define BMP180_T_DELAY          (2)
+
+static BMP180_oversampling bmp180_os = BMP180_OVERS_2;
+
+static struct {
+    int16_t     AC1;
+    int16_t     AC2;
+    int16_t     AC3;
+    uint16_t    AC4;
+    uint16_t    AC5;
+    uint16_t    AC6;
+    int16_t     B1;
+    int16_t     B2;
+    int16_t     MB;
+    int16_t     MC;
+    int16_t     MD;
+} __attribute__ ((packed)) CaliData = {0};
+
+static BMP180_status bmpstatus = BMP180_NOTINIT;
+static uint8_t calidata_rdy = 0;
+//static uint32_t milliseconds_start = 0; // time of measurement start
+//static uint32_t p_delay = 8; // delay for P measurement
+static uint8_t uncomp_data[3]; // raw uncompensated data
+static int32_t Tval; // uncompensated T value
+// compensated values:
+static uint32_t Pmeasured; // in Pa
+static int32_t  Tmeasured; // /10degC
+static uint8_t devID = 0;
+
+BMP180_status BMP180_get_status(){
+    return bmpstatus;
+}
+
+void BMP180_setOS(BMP180_oversampling os){
+    bmp180_os = os & 0x03;
+    /*
+    switch(os){
+        case BMP180_OVERS_1:
+            p_delay = 5;
+        break;
+        case BMP180_OVERS_2:
+            p_delay = 8;
+        break;
+        case BMP180_OVERS_4:
+            p_delay = 14;
+        break;
+        default:
+            p_delay = 26;
+    }*/
+}
+
+static int read_reg8(uint8_t reg, uint8_t *val){
+    if(I2C_OK != i2c_7bit_send_onebyte(reg, 0)) return 0;
+    if(I2C_OK != i2c_7bit_receive_onebyte(val, 1)) return 0;
+    return 1;
+}
+
+static int write_reg8(uint8_t reg, uint8_t val){
+    uint8_t d[2] = {reg, val};
+    if(I2C_OK != i2c_7bit_send(d, 2)) return 0;
+    return 1;
+}
+
+// get compensation data, return 1 if OK
+static int readcompdata(){
+    if(I2C_OK != i2c_7bit_send_onebyte(BMP180_REG_CALIB, 0)) return 0;
+    if(I2C_OK != i2c_7bit_receive((uint8_t*)&CaliData, sizeof(CaliData))) return 0;
+    // convert big-endian into little-endian
+    uint8_t *d, val;
+    uint16_t *arr = (uint16_t*)&CaliData;
+    for(int i = 0; i < (int)sizeof(CaliData)/2; ++i){
+        d = (uint8_t*)(&arr[i]);
+        val = d[0];
+        d[0] = d[1];
+        d[1] = val;
+    }
+    calidata_rdy = 1;
+    return 1;
+}
+
+// do a soft-reset procedure
+int BMP180_reset(){
+    if(!write_reg8(BMP180_REG_SOFTRESET, BMP180_SOFTRESET_VAL)){
+        DBG("Can't reset\n");
+        return 0;
+    }
+    return 1;
+}
+
+// read compensation data & write registers
+int BMP180_init(){
+    bmpstatus = BMP180_NOTINIT;
+    i2c_setup();
+	i2c_set_addr7(BMP180_I2C_ADDRESS);
+    if(!read_reg8(BMP180_REG_ID, &devID)) return 0;
+    DBG("Got device ID: "); DBG(u2str(devID)); DBG("\n");
+    if(devID != BMP180_CHIP_ID){
+        DBG("Not BMP180\n");
+        return 0;
+    }
+    if(!readcompdata()){
+        DBG("Can't read calibration data\n");
+    }else{
+        DBG("AC1=");
+        DBG(i2str(CaliData.AC1)); DBG(", AC2="); DBG(i2str(CaliData.AC2)); DBG(", AC3=");
+        DBG(i2str(CaliData.AC3)); DBG(", AC4="); DBG(u2str(CaliData.AC4)); DBG(", AC5=");
+        DBG(u2str(CaliData.AC5)); DBG(", AC6="); DBG(u2str(CaliData.AC6)); DBG(", B1=");
+        DBG(i2str(CaliData.B1)); DBG(", B2="); DBG(i2str(CaliData.B2)); DBG(", MB=");
+        DBG(i2str(CaliData.MB)); DBG(", MC="); DBG(i2str(CaliData.MC)); DBG(", MD=");
+        DBG(i2str(CaliData.MD)); DBG("\n");
+    }
+    return 1;
+}
+
+// @return 1 if OK, *devid -> BMP/BME
+void BMP180_read_ID(uint8_t *devid){
+    *devid = devID;
+}
+
+// start measurement, @return 1 if all OK
+int BMP180_start(/*uint32_t curr_milliseconds*/){
+    if(!calidata_rdy || bmpstatus == BMP180_BUSYT || bmpstatus == BMP180_BUSYP) return 0;
+    uint8_t reg = BMP180_READ_T | BMP180_CTRLM_SCO;
+    if(!write_reg8(BMP180_REG_CTRLMEAS, reg)){
+        DBG("Can't write CTRL reg\n");
+        return 0;
+    }
+    bmpstatus = BMP180_BUSYT;
+    //milliseconds_start = curr_milliseconds;
+    return 1;
+}
+
+
+// calculate T/10 degC and P in Pa
+static inline void compens(uint32_t Pval){
+    // T:
+    int32_t X1 = ((Tval - CaliData.AC6)*CaliData.AC5) >> 15;
+    int32_t X2 = (CaliData.MC << 11) / (X1 + CaliData.MD);
+    int32_t B5 = X1 + X2;
+    Tmeasured = (B5 + 8) >> 4;
+    // P:
+    int32_t B6 = B5 - 4000;
+    X1 = (CaliData.B2 * ((B6*B6) >> 12)) >> 11;
+    X2 = (CaliData.AC2 * B6) >> 11;
+    int32_t X3 = X1 + X2;
+    int32_t B3 = ((((CaliData.AC1 << 2) + X3) << bmp180_os) + 2) >> 2;
+    X1 = (CaliData.AC3 * B6) >> 13;
+    X2 = (CaliData.B1 * ((B6 * B6) >> 12)) >> 16;
+    X3 = ((X1 + X2) + 2) >> 2;
+    uint32_t B4 = (CaliData.AC4 * (uint32_t) (X3 + 32768)) >> 15;
+    uint32_t B7 = (uint32_t)(Pval - B3) * (50000 >> bmp180_os);
+    if(B7 < 0x80000000){
+        Pmeasured = (B7 << 1) / B4;
+    }else{
+        Pmeasured = (B7 / B4) << 1;
+    }
+    X1 = Pmeasured >> 8;
+    X1 *= X1;
+    X1 = (X1 * 3038) >> 16;
+    X2 = (-7357 * Pmeasured) >> 16;
+    Pmeasured += (X1 + X2 + 3791) >> 4;
+}
+
+static int still_measuring(){
+    uint8_t reg;
+    if(!read_reg8(BMP180_REG_CTRLMEAS, &reg)) return 1;
+    if(reg & BMP180_CTRLM_SCO){
+        DBG("Still measure\n");
+        return 1;
+    }
+    return 0;
+}
+
+void BMP180_process(/*uint32_t curr_milliseconds*/){
+    uint8_t reg;
+    if(bmpstatus != BMP180_BUSYT && bmpstatus != BMP180_BUSYP) return;
+    if(bmpstatus == BMP180_BUSYT){ // wait for temperature
+        //if(curr_milliseconds - milliseconds_start < BMP180_T_DELAY) return;
+        if(still_measuring()) return;
+        // get uncompensated data
+        DBG("Read uncompensated T\n");
+        if(I2C_OK != i2c_7bit_send_onebyte(BMP180_REG_OUT, 0)){
+            bmpstatus = BMP180_ERR;
+            return;
+        }
+        if(I2C_OK != i2c_7bit_receive(uncomp_data, 2)){
+            bmpstatus = BMP180_ERR;
+            return;
+        }
+        Tval = uncomp_data[0] << 8 | uncomp_data[1];
+        DBG("Start P measuring\n");
+        reg = BMP180_READ_P | BMP180_CTRLM_SCO | (bmp180_os << BMP180_CTRLM_OSS_SHIFT);
+        if(!write_reg8(BMP180_REG_CTRLMEAS, reg)){
+            bmpstatus = BMP180_ERR;
+            return;
+        }
+        //milliseconds_start = curr_milliseconds;
+        bmpstatus = BMP180_BUSYP;
+    }else{ // wait for pressure
+        //if(curr_milliseconds - milliseconds_start < p_delay) return;
+        if(still_measuring()) return;
+        DBG("Read uncompensated P\n");
+        if(I2C_OK != i2c_7bit_send_onebyte(BMP180_REG_OUT, 0)){
+            bmpstatus = BMP180_ERR;
+            return;
+        }
+        if(I2C_OK != i2c_7bit_receive(uncomp_data, 3)){
+            bmpstatus = BMP180_ERR;
+            return;
+        }
+        uint32_t Pval = uncomp_data[0] << 16 | uncomp_data[1] << 8 | uncomp_data[2];
+        Pval >>= (8 - bmp180_os);
+        // calculate compensated values
+        compens(Pval);
+        DBG("All data ready\n");
+        bmpstatus = BMP180_RDY; // data ready
+    }
+}
+
+// read data & convert it
+void BMP180_getdata(int32_t *T, uint32_t *P){
+    *T = Tmeasured;
+    *P = Pmeasured;
+    bmpstatus = BMP180_RELAX;
+}

F1:F103/BMP180/BMP180.h

@@ -0,0 +1,54 @@
+/*
+ * This file is part of the BMP180 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#ifndef BMP180_H__
+#define BMP180_H__
+
+#include <stm32f1.h>
+
+#define BMP180_CHIP_ID  0x55
+
+typedef enum{
+    BMP180_NOTINIT,     // wasn't inited
+    BMP180_BUSYT,       // T measurement in progress
+    BMP180_BUSYP,       // P measurement in progress
+    BMP180_ERR,         // error in I2C
+    BMP180_RELAX,       // relaxed state
+    BMP180_RDY,         // data ready - can get it
+} BMP180_status;
+
+typedef enum{
+    BMP180_OVERS_1 = 0, // oversampling is off
+    BMP180_OVERS_2 = 1,
+    BMP180_OVERS_4 = 2,
+    BMP180_OVERS_8 = 3,
+    BMP180_OVERSMAX = 4
+} BMP180_oversampling;
+
+
+int BMP180_reset();
+int BMP180_init();
+void BMP180_read_ID(uint8_t *devid);
+void BMP180_setOS(BMP180_oversampling os);
+BMP180_status BMP180_get_status();
+int BMP180_start(/*uint32_t curr_milliseconds*/);
+void BMP180_process(/*uint32_t curr_milliseconds*/);
+void BMP180_getdata(int32_t *T, uint32_t *P);
+
+#endif // BMP180_H__

F1:F103/BMP180/Makefile

@@ -0,0 +1,139 @@
+BINARY		= BMP180
+BOOTPORT	?= /dev/ttyUSB0
+BOOTSPEED	?= 115200
+# MCU FAMILY
+FAMILY		?= F1
+# MCU code
+MCU			?= F103x8
+# density (stm32f10x.h, lines 70-84)
+DENSITY 	?= MD
+# change this linking script depending on particular MCU model,
+LDSCRIPT	?= stm32f103x8.ld
+# debug
+#DEFS		= -DEBUG
+
+INDEPENDENT_HEADERS=
+
+FP_FLAGS	?= -msoft-float -mfloat-abi=soft
+ASM_FLAGS	?= -mthumb -mcpu=cortex-m3 -mfix-cortex-m3-ldrd
+ARCH_FLAGS	= $(ASM_FLAGS) $(FP_FLAGS)
+
+###############################################################################
+# Executables
+#PREFIX		?= arm-none-eabi
+# gcc from arm web site 
+PREFIX		?= /opt/bin/arm-none-eabi
+TOOLCHLIB	?= /opt/arm-none-eabi/lib
+RM			:= rm -f
+RMDIR		:= rmdir
+CC			:= $(PREFIX)-gcc
+# don't replace ld with gcc: the binary size would be much greater!!
+LD			:= $(PREFIX)-ld
+AR			:= $(PREFIX)-ar
+AS			:= $(PREFIX)-as
+SIZE 		:= $(PREFIX)-size
+OBJCOPY		:= $(PREFIX)-objcopy
+OBJDUMP		:= $(PREFIX)-objdump
+GDB			:= $(PREFIX)-gdb
+STFLASH		:= $(shell which st-flash)
+STBOOT		:= $(shell which stm32flash)
+DFUUTIL		:= $(shell which dfu-util)
+
+###############################################################################
+# Source files
+OBJDIR 		= mk
+SRC			:= $(wildcard *.c)
+OBJS		:= $(addprefix $(OBJDIR)/, $(SRC:%.c=%.o))
+STARTUP		= $(OBJDIR)/startup.o
+OBJS 		+= $(STARTUP)
+# dependencies: we need them to recompile files if their headers-dependencies changed
+DEPS		:= $(OBJS:.o=.d)
+
+INC_DIR ?= ../inc
+
+INCLUDE 	:= -I$(INC_DIR)/Fx -I$(INC_DIR)/cm
+LIB_DIR		:= $(INC_DIR)/ld
+
+###############################################################################
+# C flags
+CFLAGS		+= -O2 -g -D__thumb2__=1 -MD
+CFLAGS		+= -Wall -Werror -Wextra -Wshadow 
+CFLAGS		+= -fno-common -ffunction-sections -fdata-sections -fno-stack-protector
+CFLAGS		+=  $(ARCH_FLAGS)
+
+###############################################################################
+# Linker flags
+LDFLAGS		+= -nostartfiles --static -nostdlibs 
+LDFLAGS		+= -L$(LIB_DIR) -L$(TOOLCHLIB)
+LDFLAGS		+= -T$(LDSCRIPT)
+
+###############################################################################
+# Used libraries
+LDLIBS		+=  -lc $(shell $(CC) $(CFLAGS) -print-libgcc-file-name)
+
+DEFS		+= -DSTM32$(FAMILY) -DSTM32$(MCU) -DSTM32F10X_$(DENSITY)
+
+ELF		:= $(OBJDIR)/$(BINARY).elf
+LIST	:= $(OBJDIR)/$(BINARY).list
+BIN		:= $(BINARY).bin
+HEX		:= $(BINARY).hex
+
+all: bin list size
+
+elf: $(ELF)
+bin: $(BIN)
+hex: $(HEX)
+list: $(LIST)
+
+ifneq ($(MAKECMDGOALS),clean)
+-include $(DEPS)
+endif
+
+$(OBJDIR):
+	mkdir $(OBJDIR)
+
+$(STARTUP): $(INC_DIR)/startup/vector.c
+	$(CC) $(CFLAGS) $(DEFS) $(INCLUDE) -o $@ -c $<
+
+$(OBJDIR)/%.o: %.c
+	@echo "  CC      $<"
+	$(CC) $(CFLAGS) $(DEFS) $(INCLUDE) -o $@ -c $<
+
+$(BIN): $(ELF)
+	@echo "  OBJCOPY $(BIN)"
+	$(OBJCOPY) -Obinary $(ELF) $(BIN)
+
+$(HEX): $(ELF)
+	@echo "  OBJCOPY $(HEX)"
+	$(OBJCOPY) -Oihex $(ELF) $(HEX)
+
+$(LIST): $(ELF)
+	@echo "  OBJDUMP $(LIST)"
+	$(OBJDUMP) -S $(ELF) > $(LIST)
+
+$(ELF): $(OBJDIR) $(OBJS)
+	@echo "  LD      $(ELF)"
+	$(LD) $(LDFLAGS) $(OBJS) $(LDLIBS) -o $(ELF)
+
+size: $(ELF)
+	$(SIZE) $(ELF)    
+
+clean:
+	@echo "  CLEAN"
+	$(RM) $(OBJS) $(DEPS) $(ELF) $(HEX) $(LIST)
+	@rmdir $(OBJDIR) 2>/dev/null || true
+
+
+flash: $(BIN)
+	@echo "  FLASH  $(BIN)"
+	$(STFLASH) write $(BIN) 0x8000000
+
+boot: $(BIN)
+	@echo "  LOAD $(BIN) through bootloader"
+	$(STBOOT) -b$(BOOTSPEED) $(BOOTPORT) -w $(BIN)
+
+dfuboot: $(BIN)
+	@echo "  LOAD  $(BIN) THROUGH DFU"
+	$(DFUUTIL) -a0 -D $(BIN) -s 0x08000000
+
+.PHONY: clean flash boot

F1:F103/BMP180/Readme

@@ -0,0 +1 @@
+Work with I2C temperature/pressure sensor BMP180

F1:F103/BMP180/hardware.c

@@ -0,0 +1,48 @@
+/*
+ * This file is part of the BMP180 project.
+ * Copyright 2020 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "hardware.h"
+
+static inline void gpio_setup(){
+    // Enable clocks to the GPIO subsystems (PB for ADC), turn on AFIO clocking to disable SWD/JTAG
+    RCC->APB2ENR |= RCC_APB2ENR_IOPAEN | RCC_APB2ENR_IOPCEN | RCC_APB2ENR_AFIOEN;
+    // turn off SWJ/JTAG
+//    AFIO->MAPR = AFIO_MAPR_SWJ_CFG_DISABLE;
+    AFIO->MAPR = AFIO_MAPR_SWJ_CFG_JTAGDISABLE; // for PA15
+    // Set led as opendrain output
+    GPIOC->CRH |= CRH(13, CNF_ODOUTPUT|MODE_SLOW);
+    // USB pullup (PA15) - pushpull output
+    GPIOA->CRH = CRH(15, CNF_PPOUTPUT|MODE_SLOW);
+}
+
+void hw_setup(){
+    gpio_setup();
+}
+
+void iwdg_setup(){
+    uint32_t tmout = 16000000;
+    RCC->CSR |= RCC_CSR_LSION;
+    while((RCC->CSR & RCC_CSR_LSIRDY) != RCC_CSR_LSIRDY){if(--tmout == 0) break;} /* (2) */
+    IWDG->KR = IWDG_START;
+    IWDG->KR = IWDG_WRITE_ACCESS;
+    IWDG->PR = IWDG_PR_PR_1;
+    IWDG->RLR = 1250;
+    tmout = 16000000;
+    while(IWDG->SR){if(--tmout == 0) break;}
+    IWDG->KR = IWDG_REFRESH;
+}

F1:F103/BMP180/hardware.h

@@ -0,0 +1,43 @@
+/*
+ * This file is part of the BMP180 project.
+ * Copyright 2020 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#ifndef __HARDWARE_H__
+#define __HARDWARE_H__
+
+#include "stm32f1.h"
+
+// LED0 - PC13 (bluepill), blinking each second
+#define LED0_port   GPIOC
+#define LED0_pin    (1<<13)
+
+// USB pullup (not present in bluepill, should be soldered) - PA15
+#define USBPU_port  GPIOA
+#define USBPU_pin   (1<<15)
+#define USBPU_ON()  pin_set(USBPU_port, USBPU_pin)
+#define USBPU_OFF() pin_clear(USBPU_port, USBPU_pin)
+
+#define LED_blink(x)    pin_toggle(x ## _port, x ## _pin)
+#define LED_on(x)       pin_clear(x ## _port, x ## _pin)
+#define LED_off(x)      pin_set(x ## _port, x ## _pin)
+
+void hw_setup();
+void iwdg_setup();
+
+
+#endif // __HARDWARE_H__

F1:F103/BMP180/i2c.c

@@ -0,0 +1,236 @@
+/*
+ * This file is part of the BMP180 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "hardware.h"
+#include "i2c.h"
+
+#ifdef EBUG
+#include "usb.h"
+#include "proto.h"
+#define DBG(x)  do{USB_send(x);}while(0)
+#else
+#define DBG(x)
+#endif
+
+extern volatile uint32_t Tms;
+
+// current addresses for read/write (should be set with i2c_set_addr7)
+static uint8_t addr7r = 0, addr7w = 0;
+
+/*
+ * PB10/PB6 - I2C_SCL, PB11/PB7 - I2C_SDA or remap @ PB8 & PB9
+ */
+void i2c_setup(){
+    I2C1->CR1 = 0;
+    I2C1->SR1 = 0;
+    RCC->APB2ENR |= RCC_APB2ENR_IOPBEN;
+    GPIOB->CRL = (GPIOB->CRL & ~(GPIO_CRL_CNF6 | GPIO_CRL_CNF7)) |
+            CRL(6, CNF_AFOD | MODE_NORMAL) | CRL(7, CNF_AFOD | MODE_NORMAL);
+    RCC->APB1ENR |= RCC_APB1ENR_I2C1EN;
+    I2C1->CR2 = 8; // FREQR=8MHz, T=125ns
+    I2C1->TRISE = 9; // (9-1)*125 = 1mks
+    I2C1->CCR = 40; // normal mode, 8MHz/2/40 = 100kHz
+    I2C1->CR1 |= I2C_CR1_PE; // enable periph
+}
+
+void i2c_set_addr7(uint8_t addr){
+	addr7w = addr << 1;
+	addr7r = addr7w | 1;
+}
+
+// wait for event evt no more than 2 ms
+#define I2C_WAIT(evt)  do{ register uint32_t wait4 = Tms + 2;   \
+		while(Tms < wait4 && !(evt)) IWDG->KR = IWDG_REFRESH;   \
+		if(!(evt)){ret = I2C_TMOUT; goto eotr;}}while(0)
+// wait for !busy
+#define I2C_LINEWAIT() do{ register uint32_t wait4 = Tms + 2;                   \
+    while(Tms < wait4 && (I2C1->SR2 & I2C_SR2_BUSY)) IWDG->KR = IWDG_REFRESH;   \
+    if(I2C1->SR2 & I2C_SR2_BUSY){I2C1->CR1 |= I2C_CR1_SWRST; return I2C_LINEBUSY;}\
+    }while(0)
+
+// start writing
+static i2c_status i2c_7bit_startw(){
+    i2c_status ret = I2C_LINEBUSY;
+    DBG("SR1="); DBG(u2str(I2C1->SR1)); DBG("\n");
+    DBG("CR1="); DBG(u2str(I2C1->CR1)); DBG("\n");
+    DBG("CR2="); DBG(u2str(I2C1->CR2)); DBG("\n");
+    if(I2C1->CR1 != I2C_CR1_PE) i2c_setup();
+    if(I2C1->SR1) I2C1->SR1 = 0; // clear NACK and other problems
+    (void) I2C1->SR2;
+    I2C_LINEWAIT();
+    DBG("linew\n");
+    I2C1->CR1 |= I2C_CR1_START;             // generate start sequence
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_SB);       // wait for SB
+    DBG("SB\n");
+    (void) I2C1->SR1;                       // clear SB
+    I2C1->DR = addr7w;                      // set address
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_ADDR);     // wait for ADDR flag (timeout @ NACK)
+    DBG("ADDR\n");
+    if(I2C1->SR1 & I2C_SR1_AF){             // NACK
+        return I2C_NACK;
+    }
+    DBG("ACK\n");
+    (void) I2C1->SR2;                       // clear ADDR
+    ret = I2C_OK;
+eotr:
+    return ret;
+}
+
+/**
+ * send one byte in 7bit address mode
+ * @param data - data to write
+ * @param stop - ==1 to send stop event
+ * @return status
+ */
+i2c_status i2c_7bit_send_onebyte(uint8_t data, uint8_t stop){
+    i2c_status ret = i2c_7bit_startw();
+    if(ret != I2C_OK){
+        I2C1->CR1 |= I2C_CR1_STOP;
+        goto eotr;
+    }
+    I2C1->DR = data;                        // init data send register
+    DBG("TxE\n");
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_TXE);      // wait for TxE (timeout when NACK)
+    ret = I2C_OK;
+    DBG("OK\n");
+    if(stop){
+        I2C_WAIT(I2C1->SR1 & I2C_SR1_BTF);  // wait for BTF
+        DBG("BTF\n");
+    }
+eotr:
+    if(stop){
+        I2C1->CR1 |= I2C_CR1_STOP;          // generate stop event
+    }
+    return ret;
+}
+
+// send data array
+i2c_status i2c_7bit_send(const uint8_t *data, int datalen){
+    i2c_status ret = i2c_7bit_startw();
+    if(ret != I2C_OK){
+        I2C1->CR1 |= I2C_CR1_STOP;
+        goto eotr;
+    }
+    for(int i = 0; i < datalen; ++i){
+        I2C1->DR = data[i];
+        I2C_WAIT(I2C1->SR1 & I2C_SR1_TXE);
+    }
+    ret = I2C_OK;
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_BTF);
+eotr:
+    I2C1->CR1 |= I2C_CR1_STOP;
+    return ret;
+}
+
+i2c_status i2c_7bit_receive_onebyte(uint8_t *data, uint8_t stop){
+    i2c_status ret = I2C_LINEBUSY;
+    //I2C_LINEWAIT();
+    I2C1->CR1 |= I2C_CR1_START;             // generate start sequence
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_SB);       // wait for SB
+    DBG("Rx SB\n");
+    (void) I2C1->SR1;                       // clear SB
+    I2C1->DR = addr7r;                      // set address
+    DBG("Rx addr\n");
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_ADDR);     // wait for ADDR flag
+    DBG("Rx ack\n");
+    I2C1->CR1 &= ~I2C_CR1_ACK;              // clear ACK
+    if(I2C1->SR1 & I2C_SR1_AF){             // NACK
+        DBG("Rx nak\n");
+        ret = I2C_NACK;
+        goto eotr;
+    }
+    (void) I2C1->SR2;                       // clear ADDR
+    DBG("Rx stop\n");
+    if(stop) I2C1->CR1 |= I2C_CR1_STOP;     // program STOP
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_RXNE);     // wait for RxNE
+    DBG("Rx OK\n");
+    *data = I2C1->DR;                       // read data & clear RxNE
+    ret = I2C_OK;
+eotr:
+    return ret;
+}
+
+i2c_status i2c_7bit_receive_twobytes(uint8_t *data){
+    i2c_status ret = I2C_LINEBUSY;
+    //I2C_LINEWAIT();
+    I2C1->CR1 |= I2C_CR1_START | I2C_CR1_POS | I2C_CR1_ACK; // generate start sequence, set pos & ack
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_SB);       // wait for SB
+    DBG("2 Rx sb\n");
+    (void) I2C1->SR1;                       // clear SB
+    I2C1->DR = addr7r;                      // set address
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_ADDR);     // wait for ADDR flag
+    DBG("2 ADDR\n");
+    if(I2C1->SR1 & I2C_SR1_AF){             // NACK
+        ret = I2C_NACK;
+        goto eotr;
+    }
+    DBG("2 ACK\n");
+    (void) I2C1->SR2;                       // clear ADDR
+    I2C1->CR1 &= ~I2C_CR1_ACK;              // clear ACK
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_BTF);      // wait for BTF
+    DBG("2 BTF\n");
+    I2C1->CR1 |= I2C_CR1_STOP;              // program STOP
+    *data++ = I2C1->DR; *data = I2C1->DR;   // read data & clear RxNE
+    ret = I2C_OK;
+eotr:
+    return ret;
+}
+
+// receive any amount of bytes
+i2c_status i2c_7bit_receive(uint8_t *data, uint16_t nbytes){
+    if(nbytes == 0) return I2C_HWPROBLEM;
+    I2C1->SR1 = 0; // clear previous NACK flag & other error flags
+    if(nbytes == 1) return i2c_7bit_receive_onebyte(data, 1);
+    else if(nbytes == 2) return i2c_7bit_receive_twobytes(data);
+    i2c_status ret = I2C_LINEBUSY;
+    //I2C_LINEWAIT();
+    I2C1->CR1 |= I2C_CR1_START | I2C_CR1_ACK; // generate start sequence, set pos & ack
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_SB);       // wait for SB
+    DBG("got SB\n");
+    (void) I2C1->SR1;                       // clear SB
+    I2C1->DR = addr7r;                      // set address
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_ADDR);     // wait for ADDR flag
+    DBG("send addr\n");
+    if(I2C1->SR1 & I2C_SR1_AF){             // NACK
+        DBG("NACKed\n");
+        ret = I2C_NACK;
+        goto eotr;
+    }
+    DBG("ACKed\n");
+    (void) I2C1->SR2;                       // clear ADDR
+    for(uint16_t x = nbytes - 3; x > 0; --x){
+        I2C_WAIT(I2C1->SR1 & I2C_SR1_RXNE); // wait next byte
+        *data++ = I2C1->DR;                 // get data
+    }
+    DBG("three left\n");
+    // three bytes remain to be read
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_RXNE);     // wait dataN-2
+    DBG("dataN-2\n");
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_BTF);      // wait for BTF
+    DBG("BTF\n");
+    I2C1->CR1 &= ~I2C_CR1_ACK;              // clear ACK
+    *data++ = I2C1->DR;                     // read dataN-2
+    I2C1->CR1 |= I2C_CR1_STOP;              // program STOP
+    *data++ = I2C1->DR;                     // read dataN-1
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_RXNE);     // wait next byte
+    *data = I2C1->DR;                       // read dataN
+    DBG("got it\n");
+    ret = I2C_OK;
+eotr:
+    return ret;
+}

F1:F103/BMP180/i2c.h

@@ -0,0 +1,41 @@
+/*
+ * This file is part of the BMP180 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+#ifndef I2C_H__
+
+#include <stm32f1.h>
+
+typedef enum{
+	I2C_OK = 0,
+	I2C_LINEBUSY,
+	I2C_TMOUT,
+	I2C_NOADDR,
+	I2C_NACK,
+	I2C_HWPROBLEM,
+} i2c_status;
+
+void i2c_setup();
+void i2c_set_addr7(uint8_t addr);
+i2c_status i2c_7bit_send_onebyte(uint8_t data, uint8_t stop);
+i2c_status i2c_7bit_send(const uint8_t *data, int datalen);
+i2c_status i2c_7bit_receive_onebyte(uint8_t *data, uint8_t stop);
+i2c_status i2c_7bit_receive_twobytes(uint8_t *data);
+i2c_status i2c_7bit_receive(uint8_t *data, uint16_t nbytes);
+
+#define I2C_H__
+#endif // I2C_H__

F1:F103/BMP180/main.c

@@ -0,0 +1,105 @@
+/*
+ * This file is part of the BMP180 project.
+ * Copyright 2020 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "BMP180.h"
+#include "hardware.h"
+#include "proto.h"
+#include "usb.h"
+#include "usb_lib.h"
+
+#define USBBUFSZ    127
+
+volatile uint32_t Tms = 0;
+
+/* Called when systick fires */
+void sys_tick_handler(void){
+    ++Tms;
+}
+
+// usb getline
+static char *get_USB(){
+    static char tmpbuf[USBBUFSZ+1], *curptr = tmpbuf;
+    static int rest = USBBUFSZ;
+    int x = USB_receive(curptr);
+    curptr[x] = 0;
+    if(!x) return NULL;
+    if(curptr[x-1] == '\n'){
+        curptr = tmpbuf;
+        rest = USBBUFSZ;
+        return tmpbuf;
+    }
+    curptr += x; rest -= x;
+    if(rest <= 0){ // buffer overflow
+        curptr = tmpbuf;
+        rest = USBBUFSZ;
+        USB_send("USB buffer overflow\n");
+    }
+    return NULL;
+}
+
+int main(void){
+    uint32_t lastT = 0;
+    sysreset();
+    StartHSE();
+    hw_setup();
+    SysTick_Config(72000);
+
+    RCC->CSR |= RCC_CSR_RMVF; // remove reset flags
+
+    USBPU_OFF();
+    USB_setup();
+    BMP180_init();
+    iwdg_setup();
+    USBPU_ON();
+
+    while (1){
+        IWDG->KR = IWDG_REFRESH; // refresh watchdog
+        if(lastT > Tms || Tms - lastT > 499){
+            LED_blink(LED0);
+            lastT = Tms;
+        }
+        usb_proc();
+        BMP180_process(/*Tms*/);
+        BMP180_status s = BMP180_get_status();
+        if(s == BMP180_RDY){ // data ready - get it
+            int32_t T;
+            uint32_t P;
+            BMP180_getdata(&T, &P);
+            USB_send("T="); USB_send(i2str(T)); USB_send(" (/10degC)\nP=");
+            USB_send(u2str(P)); USB_send(" (Pa) or ");
+            float mm = P*0.0750062;
+            USB_send(u2str(mm)); USB_send(" (/10mmHg)\n");
+        }else if(s == BMP180_ERR){
+            USB_send("Error in measurement\n");
+            BMP180_reset();
+            BMP180_init();
+        }
+
+        char *txt, *ans;
+        if((txt = get_USB())){
+            IWDG->KR = IWDG_REFRESH;
+            ans = (char*)parse_cmd(txt);
+            if(ans){
+                uint16_t l = 0; char *p = ans;
+                while(*p++) l++;
+                USB_send(ans);
+            }
+        }
+    }
+    return 0;
+}

F1:F103/BMP180/proto.c

@@ -0,0 +1,242 @@
+/*
+ * This file is part of the BMP180 project.
+ * Copyright 2020 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "BMP180.h"
+#include "proto.h"
+#include "usb.h"
+
+extern volatile uint32_t Tms;
+
+char *omit_spaces(const char *buf){
+    while(*buf){
+        if(*buf > ' ') break;
+        ++buf;
+    }
+    return (char*)buf;
+}
+
+// In case of overflow return `buf` and N==0xffffffff
+// read decimal number & return pointer to next non-number symbol
+static char *getdec(const char *buf, uint32_t *N){
+    char *start = (char*)buf;
+    uint32_t num = 0;
+    while(*buf){
+        char c = *buf;
+        if(c < '0' || c > '9'){
+            break;
+        }
+        if(num > 429496729 || (num == 429496729 && c > '5')){ // overflow
+            *N = 0xffffff;
+            return start;
+        }
+        num *= 10;
+        num += c - '0';
+        ++buf;
+    }
+    *N = num;
+    return (char*)buf;
+}
+// read hexadecimal number (without 0x prefix!)
+static char *gethex(const char *buf, uint32_t *N){
+    char *start = (char*)buf;
+    uint32_t num = 0;
+    while(*buf){
+        char c = *buf;
+        uint8_t M = 0;
+        if(c >= '0' && c <= '9'){
+            M = '0';
+        }else if(c >= 'A' && c <= 'F'){
+            M = 'A' - 10;
+        }else if(c >= 'a' && c <= 'f'){
+            M = 'a' - 10;
+        }
+        if(M){
+            if(num & 0xf0000000){ // overflow
+                *N = 0xffffff;
+                return start;
+            }
+            num <<= 4;
+            num += c - M;
+        }else{
+            break;
+        }
+        ++buf;
+    }
+    *N = num;
+    return (char*)buf;
+}
+// read octal number (without 0 prefix!)
+static char *getoct(const char *buf, uint32_t *N){
+    char *start = (char*)buf;
+    uint32_t num = 0;
+    while(*buf){
+        char c = *buf;
+        if(c < '0' || c > '7'){
+            break;
+        }
+        if(num & 0xe0000000){ // overflow
+            *N = 0xffffff;
+            return start;
+        }
+        num <<= 3;
+        num += c - '0';
+        ++buf;
+    }
+    *N = num;
+    return (char*)buf;
+}
+// read binary number (without b prefix!)
+static char *getbin(const char *buf, uint32_t *N){
+    char *start = (char*)buf;
+    uint32_t num = 0;
+    while(*buf){
+        char c = *buf;
+        if(c < '0' || c > '1'){
+            break;
+        }
+        if(num & 0x80000000){ // overflow
+            *N = 0xffffff;
+            return start;
+        }
+        num <<= 1;
+        if(c == '1') num |= 1;
+        ++buf;
+    }
+    *N = num;
+    return (char*)buf;
+}
+
+/**
+ * @brief getnum - read uint32_t from string (dec, hex or bin: 127, 0x7f, 0b1111111)
+ * @param buf - buffer with number and so on
+ * @param N   - the number read
+ * @return pointer to first non-number symbol in buf
+ *      (if it is == buf, there's no number or if *N==0xffffffff there was overflow)
+ */
+char *getnum(const char *txt, uint32_t *N){
+    char *nxt = NULL;
+    char *s = omit_spaces(txt);
+    if(*s == '0'){ // hex, oct or 0
+        if(s[1] == 'x' || s[1] == 'X'){ // hex
+            nxt = gethex(s+2, N);
+            if(nxt == s+2) nxt = (char*)txt;
+        }else if(s[1] > '0'-1 && s[1] < '8'){ // oct
+            nxt = getoct(s+1, N);
+            if(nxt == s+1) nxt = (char*)txt;
+        }else{ // 0
+            nxt = s+1;
+            *N = 0;
+        }
+    }else if(*s == 'b' || *s == 'B'){
+        nxt = getbin(s+1, N);
+        if(nxt == s+1) nxt = (char*)txt;
+    }else{
+        nxt = getdec(s, N);
+        if(nxt == s) nxt = (char*)txt;
+    }
+    return nxt;
+}
+
+const char* helpmsg =
+    "'0' - reset BMP180\n"
+    "'1' - init BMP180\n"
+    "'I' - read chip ID (after init)\n"
+    "'M' - start measurements\n"
+    "'Ox' - set oversampling of p to x(0..3)\n"
+    "'R' - software reset\n"
+    "'W' - test watchdog\n"
+;
+
+const char *parse_cmd(const char *buf){
+    uint8_t u;
+    if(buf[1] == '\n'){ // one symbol commands
+        switch(*buf){
+            case '0':
+                if(BMP180_reset()) return "Reseted\n";
+                else return "Error in reset\n";
+            break;
+            case '1':
+                if(!BMP180_init())  return "Error in init process\n";
+                return "OK, inited\n";
+            break;
+            case 'I':
+                BMP180_read_ID(&u);
+                if(u == BMP180_CHIP_ID) return "BMP180\n";
+                else return "ID unknown\n";
+            break;
+            case 'M':
+                if(!BMP180_start(/*Tms*/)) return "BMP180 not found or not inited\n";
+                else return "Start\n";
+            break;
+            case 'R':
+                USB_send("Soft reset\n");
+                NVIC_SystemReset();
+            break;
+            case 'W':
+                USB_send("Wait for reboot\n");
+                while(1){nop();};
+            break;
+            default:
+                return helpmsg;
+        }
+        return NULL;
+    }
+    uint32_t Num = 0;
+    switch(*buf){ // long messages
+        case 'O':
+            ++buf;
+            if(buf != getnum(buf, &Num) && Num < BMP180_OVERSMAX){
+                BMP180_setOS(Num);
+                return "Changed\n";
+            }else return "Wrong OS number";
+        break;
+        default:
+            return buf;
+    }
+    return NULL;
+}
+
+static char *_2str(uint32_t  val, uint8_t minus){
+    static char strbuf[12];
+    char *bufptr = &strbuf[11];
+    *bufptr = 0;
+    if(!val){
+        *(--bufptr) = '0';
+    }else{
+        while(val){
+            *(--bufptr) = val % 10 + '0';
+            val /= 10;
+        }
+    }
+    if(minus) *(--bufptr) = '-';
+    return bufptr;
+}
+
+// return string with number `val`
+char *u2str(uint32_t val){
+    return _2str(val, 0);
+}
+char *i2str(int32_t i){
+    uint8_t minus = 0;
+    uint32_t val;
+    if(i < 0){
+        minus = 1;
+        val = -i;
+    }else val = i;
+    return _2str(val, minus);
+}

F1:F103/BMP180/proto.h

@@ -0,0 +1,30 @@
+/*
+ * This file is part of the BMP180 project.
+ * Copyright 2020 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+#ifndef PROTO_H__
+#define PROTO_H__
+
+#include <stm32f1.h>
+
+const char *parse_cmd(const char *buf);
+char *omit_spaces(const char *buf);
+char *getnum(const char *buf, uint32_t *N);
+char *u2str(uint32_t val);
+char *i2str(int32_t val);
+
+#endif // PROTO_H__

F1:F103/BMP180/usb.c

@@ -0,0 +1,167 @@
+/*
+ * This file is part of the BMP180 project.
+ * Copyright 2020 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "usb.h"
+#include "usb_lib.h"
+
+static volatile uint8_t tx_succesfull = 1;
+static volatile uint8_t rxNE = 0;
+
+static int sstrlen(const char *s){
+    if(!s) return 0;
+    int l = 0;
+    while(*s++) ++l;
+    return l;
+}
+
+// interrupt IN handler (never used?)
+static void EP1_Handler(){
+    uint16_t epstatus = KEEP_DTOG(USB->EPnR[1]);
+    if(RX_FLAG(epstatus)) epstatus = (epstatus & ~USB_EPnR_STAT_TX) ^ USB_EPnR_STAT_RX; // set valid RX
+    else epstatus = epstatus & ~(USB_EPnR_STAT_TX|USB_EPnR_STAT_RX);
+    // clear CTR
+    epstatus = (epstatus & ~(USB_EPnR_CTR_RX|USB_EPnR_CTR_TX));
+    USB->EPnR[1] = epstatus;
+}
+
+// data IN/OUT handlers
+static void transmit_Handler(){ // EP3IN
+    tx_succesfull = 1;
+    uint16_t epstatus = KEEP_DTOG_STAT(USB->EPnR[3]);
+    // clear CTR keep DTOGs & STATs
+    USB->EPnR[3] = (epstatus & ~(USB_EPnR_CTR_TX)); // clear TX ctr
+}
+
+static void receive_Handler(){ // EP2OUT
+    rxNE = 1;
+    uint16_t epstatus = KEEP_DTOG_STAT(USB->EPnR[2]);
+    USB->EPnR[2] = (epstatus & ~(USB_EPnR_CTR_RX)); // clear RX ctr
+}
+
+void USB_setup(){
+    NVIC_DisableIRQ(USB_LP_CAN1_RX0_IRQn);
+    NVIC_DisableIRQ(USB_HP_CAN1_TX_IRQn);
+    RCC->APB1ENR |= RCC_APB1ENR_USBEN;
+    USB->CNTR   = USB_CNTR_FRES; // Force USB Reset
+    for(uint32_t ctr = 0; ctr < 72000; ++ctr) nop(); // wait >1ms
+    //uint32_t ctr = 0;
+    USB->CNTR   = 0;
+    USB->BTABLE = 0;
+    USB->DADDR  = 0;
+    USB->ISTR   = 0;
+    USB->CNTR   = USB_CNTR_RESETM | USB_CNTR_WKUPM; // allow only wakeup & reset interrupts
+    NVIC_EnableIRQ(USB_LP_CAN1_RX0_IRQn);
+}
+
+static int usbwr(const char *buf, int l){
+    uint32_t ctra = 1000000;
+    while(--ctra && tx_succesfull == 0){
+        IWDG->KR = IWDG_REFRESH;
+    }
+    tx_succesfull = 0;
+    EP_Write(3, (uint8_t*)buf, l);
+    ctra = 1000000;
+    while(--ctra && tx_succesfull == 0){
+        IWDG->KR = IWDG_REFRESH;
+    }
+    if(tx_succesfull == 0){usbON = 0; return 1;} // usb is OFF?
+    return 0;
+}
+
+static char usbbuff[USB_TXBUFSZ-1]; // temporary buffer (63 - to prevent need of ZLP)
+static int buflen = 0; // amount of symbols in usbbuff
+
+// send next up to 63 bytes of data in usbbuff
+static void send_next(){
+    if(!buflen || !tx_succesfull) return;
+    tx_succesfull = 0;
+    EP_Write(3, (uint8_t*)usbbuff, buflen);
+    buflen = 0;
+}
+
+// unblocking sending - just fill a buffer
+void USB_send(const char *buf){
+    int len = sstrlen(buf);
+    if(!usbON || !len) return;
+    if(len > USB_TXBUFSZ-1 - buflen){
+        usbwr(usbbuff, buflen);
+        buflen = 0;
+    }
+    if(len > USB_TXBUFSZ-1){
+        USB_send_blk(buf, len);
+        return;
+    }
+    while(len--) usbbuff[buflen++] = *buf++;
+}
+
+// blocking sending
+void USB_send_blk(const char *buf, int len){
+    if(!usbON || !len) return; // USB disconnected
+    if(buflen){
+        usbwr(usbbuff, buflen);
+        buflen = 0;
+    }
+    int needzlp = 0;
+    while(len){
+        if(len == USB_TXBUFSZ) needzlp = 1;
+        int s = (len > USB_TXBUFSZ) ? USB_TXBUFSZ : len;
+        if(usbwr(buf, s)) return;
+        len -= s;
+        buf += s;
+    }
+    if(needzlp){
+        usbwr(NULL, 0);
+    }
+}
+
+void usb_proc(){
+    switch(USB_Dev.USB_Status){
+        case USB_STATE_CONFIGURED:
+            // make new BULK endpoint
+            // Buffer have 1024 bytes, but last 256 we use for CAN bus (30.2 of RM: USB main features)
+            EP_Init(1, EP_TYPE_INTERRUPT, USB_EP1BUFSZ, 0, EP1_Handler); // IN1 - transmit
+            EP_Init(2, EP_TYPE_BULK, 0, USB_RXBUFSZ, receive_Handler); // OUT2 - receive data
+            EP_Init(3, EP_TYPE_BULK, USB_TXBUFSZ, 0, transmit_Handler); // IN3 - transmit data
+            USB_Dev.USB_Status = USB_STATE_CONNECTED;
+        break;
+        case USB_STATE_DEFAULT:
+        case USB_STATE_ADDRESSED:
+            if(usbON){
+                usbON = 0;
+            }
+        break;
+        default: // USB_STATE_CONNECTED - send next data portion
+            if(!usbON) return;
+            send_next();
+    }
+}
+
+/**
+ * @brief USB_receive
+ * @param buf (i) - buffer[64] for received data
+ * @return amount of received bytes
+ */
+int USB_receive(char *buf){
+    if(!usbON || !rxNE) return 0;
+    int sz = EP_Read(2, (uint16_t*)buf);
+    uint16_t epstatus = KEEP_DTOG(USB->EPnR[2]);
+    // keep stat_tx & set ACK rx
+    USB->EPnR[2] = (epstatus & ~(USB_EPnR_STAT_TX)) ^ USB_EPnR_STAT_RX;
+    rxNE = 0;
+    return sz;
+}

F1:F103/BMP180/usb.h

@@ -0,0 +1,33 @@
+/*
+ * This file is part of the BMP180 project.
+ * Copyright 2020 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#ifndef __USB_H__
+#define __USB_H__
+
+#include "hardware.h"
+
+#define BUFFSIZE   (64)
+
+void USB_setup();
+void usb_proc();
+void USB_send(const char *buf);
+void USB_send_blk(const char *buf, int len);
+int USB_receive(char *buf);
+
+#endif // __USB_H__

F1:F103/BMP180/usb_defs.h

@@ -0,0 +1,102 @@
+/*
+ * This file is part of the BMP180 project.
+ * Copyright 2020 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#ifndef __USB_DEFS_H__
+#define __USB_DEFS_H__
+
+#include <stm32f1.h>
+
+// max endpoints number
+#define STM32ENDPOINTS          8
+/**
+ *                 Buffers size definition
+ **/
+#define USB_BTABLE_SIZE         512
+// first 64 bytes of USB_BTABLE are registers!
+//#define USB_EP0_BASEADDR        64
+// for USB FS EP0 buffers are from 8 to 64 bytes long (64 for PL2303)
+#define USB_EP0_BUFSZ           64
+// USB transmit buffer size (64 for PL2303)
+#define USB_TXBUFSZ             64
+// USB receive buffer size (64 for PL2303)
+#define USB_RXBUFSZ             64
+// EP1 - interrupt - buffer size
+#define USB_EP1BUFSZ            8
+
+#define USB_BTABLE_BASE         0x40006000
+#define USB_BASE                ((uint32_t)0x40005C00)
+#define USB                     ((USB_TypeDef *) USB_BASE)
+
+#ifdef USB_BTABLE
+#undef USB_BTABLE
+#endif
+#define USB_BTABLE              ((USB_BtableDef *)(USB_BTABLE_BASE))
+#define USB_ISTR_EPID           0x0000000F
+#define USB_FNR_LSOF_0          0x00000800
+#define USB_FNR_lSOF_1          0x00001000
+#define USB_LPMCSR_BESL_0       0x00000010
+#define USB_LPMCSR_BESL_1       0x00000020
+#define USB_LPMCSR_BESL_2       0x00000040
+#define USB_LPMCSR_BESL_3       0x00000080
+#define USB_EPnR_CTR_RX         0x00008000
+#define USB_EPnR_DTOG_RX        0x00004000
+#define USB_EPnR_STAT_RX        0x00003000
+#define USB_EPnR_STAT_RX_0      0x00001000
+#define USB_EPnR_STAT_RX_1      0x00002000
+#define USB_EPnR_SETUP          0x00000800
+#define USB_EPnR_EP_TYPE        0x00000600
+#define USB_EPnR_EP_TYPE_0      0x00000200
+#define USB_EPnR_EP_TYPE_1      0x00000400
+#define USB_EPnR_EP_KIND        0x00000100
+#define USB_EPnR_CTR_TX         0x00000080
+#define USB_EPnR_DTOG_TX        0x00000040
+#define USB_EPnR_STAT_TX        0x00000030
+#define USB_EPnR_STAT_TX_0      0x00000010
+#define USB_EPnR_STAT_TX_1      0x00000020
+#define USB_EPnR_EA             0x0000000F
+#define USB_COUNTn_RX_BLSIZE    0x00008000
+#define USB_COUNTn_NUM_BLOCK    0x00007C00
+#define USB_COUNTn_RX           0x0000003F
+
+#ifdef USB_TypeDef
+#define USB_TypeDef USB_TypeDef_custom
+#endif
+
+typedef struct {
+    __IO uint32_t EPnR[STM32ENDPOINTS];
+    __IO uint32_t RESERVED[STM32ENDPOINTS];
+    __IO uint32_t CNTR;
+    __IO uint32_t ISTR;
+    __IO uint32_t FNR;
+    __IO uint32_t DADDR;
+    __IO uint32_t BTABLE;
+} USB_TypeDef;
+
+typedef struct{
+    __IO uint32_t USB_ADDR_TX;
+    __IO uint32_t USB_COUNT_TX;
+    __IO uint32_t USB_ADDR_RX;
+    __IO uint32_t USB_COUNT_RX;
+} USB_EPDATA_TypeDef;
+
+typedef struct{
+    __IO USB_EPDATA_TypeDef EP[STM32ENDPOINTS];
+} USB_BtableDef;
+
+#endif // __USB_DEFS_H__

F1:F103/BMP180/usb_lib.c

@@ -0,0 +1,476 @@
+/*
+ * This file is part of the BMP180 project.
+ * Copyright 2020 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdint.h>
+#include "usb_lib.h"
+
+ep_t endpoints[STM32ENDPOINTS];
+
+usb_dev_t USB_Dev;
+static usb_LineCoding lineCoding = {115200, 0, 0, 8};
+static config_pack_t setup_packet;
+static uint8_t ep0databuf[EP0DATABUF_SIZE];
+static uint8_t ep0dbuflen = 0;
+
+usb_LineCoding getLineCoding(){return lineCoding;}
+
+uint8_t usbON = 0; // device disconnected from terminal
+
+// definition of parts common for USB_DeviceDescriptor & USB_DeviceQualifierDescriptor
+#define bcdUSB_L        0x10
+#define bcdUSB_H        0x01
+#define bDeviceClass    0
+#define bDeviceSubClass 0
+#define bDeviceProtocol 0
+#define bNumConfigurations 1
+
+static const uint8_t USB_DeviceDescriptor[] = {
+        18,     // bLength
+        0x01,   // bDescriptorType - Device descriptor
+        bcdUSB_L,   // bcdUSB_L - 1.10
+        bcdUSB_H,   // bcdUSB_H
+        bDeviceClass,   // bDeviceClass - USB_COMM
+        bDeviceSubClass,   // bDeviceSubClass
+        bDeviceProtocol,   // bDeviceProtocol
+        USB_EP0_BUFSZ,   // bMaxPacketSize
+        0x7b,   // idVendor_L PL2303: VID=0x067b, PID=0x2303
+        0x06,   // idVendor_H
+        0x03,   // idProduct_L
+        0x23,   // idProduct_H
+        0x00,   // bcdDevice_Ver_L
+        0x03,   // bcdDevice_Ver_H
+        0x01,   // iManufacturer
+        0x02,   // iProduct
+        0x00,   // iSerialNumber
+        bNumConfigurations    // bNumConfigurations
+};
+
+static const uint8_t USB_DeviceQualifierDescriptor[] = {
+        10,     //bLength
+        0x06,   // bDescriptorType - Device qualifier
+        bcdUSB_L,   // bcdUSB_L
+        bcdUSB_H,   // bcdUSB_H
+        bDeviceClass,   // bDeviceClass
+        bDeviceSubClass,   // bDeviceSubClass
+        bDeviceProtocol,   // bDeviceProtocol
+        USB_EP0_BUFSZ,   // bMaxPacketSize0
+        bNumConfigurations,   // bNumConfigurations
+        0x00    // Reserved
+};
+
+static const uint8_t USB_ConfigDescriptor[] = {
+        /*Configuration Descriptor*/
+        0x09, /* bLength: Configuration Descriptor size */
+        0x02, /* bDescriptorType: Configuration */
+        39,   /* wTotalLength:no of returned bytes */
+        0x00,
+        0x01, /* bNumInterfaces: 1 interface */
+        0x01, /* bConfigurationValue: Configuration value */
+        0x00, /* iConfiguration: Index of string descriptor describing the configuration */
+        0xa0, /* bmAttributes - Bus powered, Remote wakeup */
+        0x32, /* MaxPower 100 mA */
+
+        /*---------------------------------------------------------------------------*/
+
+        /*Interface Descriptor */
+        0x09, /* bLength: Interface Descriptor size */
+        0x04, /* bDescriptorType: Interface */
+        0x00, /* bInterfaceNumber: Number of Interface */
+        0x00, /* bAlternateSetting: Alternate setting */
+        0x03, /* bNumEndpoints: 3 endpoints used */
+        0xff, /* bInterfaceClass */
+        0x00, /* bInterfaceSubClass */
+        0x00, /* bInterfaceProtocol */
+        0x00, /* iInterface: */
+///////////////////////////////////////////////////
+        /*Endpoint 1 Descriptor*/
+        0x07, /* bLength: Endpoint Descriptor size */
+        0x05, /* bDescriptorType: Endpoint */
+        0x81, /* bEndpointAddress IN1 */
+        0x03, /* bmAttributes: Interrupt */
+        0x0a, /* wMaxPacketSize LO: */
+        0x00, /* wMaxPacketSize HI: */
+        0x01, /* bInterval: */
+
+        /*Endpoint OUT2 Descriptor*/
+        0x07, /* bLength: Endpoint Descriptor size */
+        0x05, /* bDescriptorType: Endpoint */
+        0x02, /* bEndpointAddress: OUT2 */
+        0x02, /* bmAttributes: Bulk */
+        (USB_RXBUFSZ & 0xff), /* wMaxPacketSize: 64 */
+        (USB_RXBUFSZ >> 8),
+        0x00, /* bInterval: ignore for Bulk transfer */
+
+        /*Endpoint IN3 Descriptor*/
+        0x07, /* bLength: Endpoint Descriptor size */
+        0x05, /* bDescriptorType: Endpoint */
+        0x83, /* bEndpointAddress IN3 */
+        0x02, /* bmAttributes: Bulk */
+        (USB_TXBUFSZ & 0xff), /* wMaxPacketSize: 64 */
+        (USB_TXBUFSZ >> 8),
+        0x00, /* bInterval: ignore for Bulk transfer */
+};
+
+_USB_LANG_ID_(USB_StringLangDescriptor, LANG_US);
+// these descriptors are not used in PL2303 emulator!
+_USB_STRING_(USB_StringSerialDescriptor, u"0");
+_USB_STRING_(USB_StringManufacturingDescriptor, u"Prolific Technology Inc.");
+_USB_STRING_(USB_StringProdDescriptor, u"USB-Serial Controller");
+
+/*
+ * default handlers
+ */
+// SET_LINE_CODING
+void WEAK linecoding_handler(usb_LineCoding __attribute__((unused)) *lc){
+}
+
+// SET_CONTROL_LINE_STATE
+void WEAK clstate_handler(uint16_t __attribute__((unused)) val){
+}
+
+// SEND_BREAK
+void WEAK break_handler(){
+}
+
+// handler of vendor requests
+void WEAK vendor_handler(config_pack_t *packet){
+    if(packet->bmRequestType & 0x80){ // read
+        uint8_t c;
+        switch(packet->wValue){
+            case 0x8484:
+                c = 2;
+            break;
+            case 0x0080:
+                c = 1;
+            break;
+            case 0x8686:
+                c = 0xaa;
+            break;
+            default:
+                c = 0;
+        }
+        EP_WriteIRQ(0, &c, 1);
+    }else{ // write ZLP
+        EP_WriteIRQ(0, (uint8_t *)0, 0);
+    }
+}
+
+static void wr0(const uint8_t *buf, uint16_t size){
+    if(setup_packet.wLength < size) size = setup_packet.wLength; // shortened request
+    if(size < endpoints[0].txbufsz){
+        EP_WriteIRQ(0, buf, size);
+        return;
+    }
+    while(size){
+        uint16_t l = size;
+        if(l > endpoints[0].txbufsz) l = endpoints[0].txbufsz;
+        EP_WriteIRQ(0, buf, l);
+        buf += l;
+        size -= l;
+        uint8_t needzlp = (l == endpoints[0].txbufsz) ? 1 : 0;
+        if(size || needzlp){ // send last data buffer
+            uint16_t status = KEEP_DTOG(USB->EPnR[0]);
+            // keep DTOGs, clear CTR_RX,TX, set TX VALID, leave stat_Rx
+            USB->EPnR[0] = (status & ~(USB_EPnR_CTR_RX|USB_EPnR_CTR_TX|USB_EPnR_STAT_RX))
+                            ^ USB_EPnR_STAT_TX;
+            uint32_t ctr = 1000000;
+            while(--ctr && (USB->ISTR & USB_ISTR_CTR) == 0){IWDG->KR = IWDG_REFRESH;};
+            if((USB->ISTR & USB_ISTR_CTR) == 0){
+                return;
+            }
+            if(needzlp) EP_WriteIRQ(0, (uint8_t*)0, 0);
+        }
+    }
+}
+
+static inline void get_descriptor(){
+    switch(setup_packet.wValue){
+        case DEVICE_DESCRIPTOR:
+            wr0(USB_DeviceDescriptor, sizeof(USB_DeviceDescriptor));
+        break;
+        case CONFIGURATION_DESCRIPTOR:
+            wr0(USB_ConfigDescriptor, sizeof(USB_ConfigDescriptor));
+        break;
+        case STRING_LANG_DESCRIPTOR:
+            wr0((const uint8_t *)&USB_StringLangDescriptor, STRING_LANG_DESCRIPTOR_SIZE_BYTE);
+        break;
+        case STRING_MAN_DESCRIPTOR:
+            wr0((const uint8_t *)&USB_StringManufacturingDescriptor, USB_StringManufacturingDescriptor.bLength);
+        break;
+        case STRING_PROD_DESCRIPTOR:
+            wr0((const uint8_t *)&USB_StringProdDescriptor, USB_StringProdDescriptor.bLength);
+        break;
+        case STRING_SN_DESCRIPTOR:
+            wr0((const uint8_t *)&USB_StringSerialDescriptor, USB_StringSerialDescriptor.bLength);
+        break;
+        case DEVICE_QUALIFIER_DESCRIPTOR:
+            wr0(USB_DeviceQualifierDescriptor, USB_DeviceQualifierDescriptor[0]);
+        break;
+        default:
+        break;
+    }
+}
+
+static uint8_t configuration = 0; // reply for GET_CONFIGURATION (==1 if configured)
+static inline void std_d2h_req(){
+    uint16_t status = 0; // bus powered
+    switch(setup_packet.bRequest){
+        case GET_DESCRIPTOR:
+            get_descriptor();
+        break;
+        case GET_STATUS:
+            EP_WriteIRQ(0, (uint8_t *)&status, 2); // send status: Bus Powered
+        break;
+        case GET_CONFIGURATION:
+            EP_WriteIRQ(0, &configuration, 1);
+        break;
+        default:
+        break;
+    }
+}
+
+static inline void std_h2d_req(){
+    switch(setup_packet.bRequest){
+        case SET_ADDRESS:
+            // new address will be assigned later - after  acknowlegement or request to host
+            USB_Dev.USB_Addr = setup_packet.wValue;
+        break;
+        case SET_CONFIGURATION:
+            // Now device configured
+            USB_Dev.USB_Status = USB_STATE_CONFIGURED;
+            configuration = setup_packet.wValue;
+        break;
+        default:
+        break;
+    }
+}
+
+/*
+bmRequestType: 76543210
+7    direction: 0 - host->device, 1 - device->host
+65   type: 0 - standard, 1 - class, 2 - vendor
+4..0 getter: 0 - device, 1 - interface, 2 - endpoint, 3 - other
+*/
+/**
+ * Endpoint0 (control) handler
+ */
+static void EP0_Handler(){
+    uint16_t epstatus = USB->EPnR[0]; // EP0R on input -> return this value after modifications
+    uint8_t reqtype = setup_packet.bmRequestType & 0x7f;
+    uint8_t dev2host = (setup_packet.bmRequestType & 0x80) ? 1 : 0;
+    int rxflag = RX_FLAG(epstatus);
+    if(rxflag && SETUP_FLAG(epstatus)){
+        switch(reqtype){
+            case STANDARD_DEVICE_REQUEST_TYPE: // standard device request
+                if(dev2host){
+                    std_d2h_req();
+                }else{
+                    std_h2d_req();
+                    EP_WriteIRQ(0, (uint8_t *)0, 0);
+                }
+            break;
+            case STANDARD_ENDPOINT_REQUEST_TYPE: // standard endpoint request
+                if(setup_packet.bRequest == CLEAR_FEATURE){
+                    EP_WriteIRQ(0, (uint8_t *)0, 0);
+                }
+            break;
+            case VENDOR_REQUEST_TYPE:
+                vendor_handler(&setup_packet);
+            break;
+            case CONTROL_REQUEST_TYPE:
+                switch(setup_packet.bRequest){
+                    case GET_LINE_CODING:
+                        EP_WriteIRQ(0, (uint8_t*)&lineCoding, sizeof(lineCoding));
+                    break;
+                    case SET_LINE_CODING: // omit this for next stage, when data will come
+                    break;
+                    case SET_CONTROL_LINE_STATE:
+                        usbON = 1;
+                        clstate_handler(setup_packet.wValue);
+                    break;
+                    case SEND_BREAK:
+                        usbON = 0;
+                        break_handler();
+                    break;
+                    default:
+                    break;
+                }
+                if(setup_packet.bRequest != GET_LINE_CODING) EP_WriteIRQ(0, (uint8_t *)0, 0); // write acknowledgement
+            break;
+            default:
+                EP_WriteIRQ(0, (uint8_t *)0, 0);
+        }
+    }else if(rxflag){ // got data over EP0 or host acknowlegement
+        if(endpoints[0].rx_cnt){
+            if(setup_packet.bRequest == SET_LINE_CODING){
+                linecoding_handler((usb_LineCoding*)ep0databuf);
+            }
+        }
+    } else if(TX_FLAG(epstatus)){ // package transmitted
+        // now we can change address after enumeration
+        if ((USB->DADDR & USB_DADDR_ADD) != USB_Dev.USB_Addr){
+            USB->DADDR = USB_DADDR_EF | USB_Dev.USB_Addr;
+            // change state to ADRESSED
+            USB_Dev.USB_Status = USB_STATE_ADDRESSED;
+        }
+    }
+    epstatus = KEEP_DTOG(USB->EPnR[0]);
+    if(rxflag) epstatus ^= USB_EPnR_STAT_TX; // start ZLP/data transmission
+    else epstatus &= ~USB_EPnR_STAT_TX; // or leave unchanged
+    // keep DTOGs, clear CTR_RX,TX, set RX VALID
+    USB->EPnR[0] = (epstatus & ~(USB_EPnR_CTR_RX|USB_EPnR_CTR_TX)) ^ USB_EPnR_STAT_RX;
+}
+
+static uint16_t lastaddr = LASTADDR_DEFAULT;
+/**
+ * Endpoint initialisation
+ * @param number - EP num (0...7)
+ * @param type - EP type (EP_TYPE_BULK, EP_TYPE_CONTROL, EP_TYPE_ISO, EP_TYPE_INTERRUPT)
+ * @param txsz - transmission buffer size @ USB/CAN buffer
+ * @param rxsz - reception buffer size @ USB/CAN buffer
+ * @param uint16_t (*func)(ep_t *ep) - EP handler function
+ * @return 0 if all OK
+ */
+int EP_Init(uint8_t number, uint8_t type, uint16_t txsz, uint16_t rxsz, void (*func)(ep_t ep)){
+    if(number >= STM32ENDPOINTS) return 4; // out of configured amount
+    if(txsz > USB_BTABLE_SIZE || rxsz > USB_BTABLE_SIZE) return 1; // buffer too large
+    if(lastaddr + txsz + rxsz >= USB_BTABLE_SIZE) return 2; // out of btable
+    USB->EPnR[number] = (type << 9) | (number & USB_EPnR_EA);
+    USB->EPnR[number] ^= USB_EPnR_STAT_RX | USB_EPnR_STAT_TX_1;
+    if(rxsz & 1 || rxsz > 512) return 3; // wrong rx buffer size
+    uint16_t countrx = 0;
+    if(rxsz < 64) countrx = rxsz / 2;
+    else{
+        if(rxsz & 0x1f) return 3; // should be multiple of 32
+        countrx = 31 + rxsz / 32;
+    }
+    USB_BTABLE->EP[number].USB_ADDR_TX = lastaddr;
+    endpoints[number].tx_buf = (uint16_t *)(USB_BTABLE_BASE + lastaddr*2);
+    endpoints[number].txbufsz = txsz;
+    lastaddr += txsz;
+    USB_BTABLE->EP[number].USB_COUNT_TX = 0;
+    USB_BTABLE->EP[number].USB_ADDR_RX = lastaddr;
+    endpoints[number].rx_buf = (uint16_t *)(USB_BTABLE_BASE + lastaddr*2);
+    lastaddr += rxsz;
+    USB_BTABLE->EP[number].USB_COUNT_RX = countrx << 10;
+    endpoints[number].func = func;
+    return 0;
+}
+
+// standard IRQ handler
+void usb_lp_can_rx0_isr(){
+    if(USB->ISTR & USB_ISTR_RESET){
+        usbON = 0;
+        // Reinit registers
+        USB->CNTR = USB_CNTR_RESETM | USB_CNTR_CTRM | USB_CNTR_SUSPM | USB_CNTR_WKUPM;
+        USB->ISTR = 0;
+        // Endpoint 0 - CONTROL
+        // ON USB LS size of EP0 may be 8 bytes, but on FS it should be 64 bytes!
+        lastaddr = LASTADDR_DEFAULT;
+        // clear address, leave only enable bit
+        USB->DADDR = USB_DADDR_EF;
+        USB_Dev.USB_Status = USB_STATE_DEFAULT;
+        USB->ISTR = ~USB_ISTR_RESET;
+        if(EP_Init(0, EP_TYPE_CONTROL, USB_EP0_BUFSZ, USB_EP0_BUFSZ, EP0_Handler)){
+            return;
+        }
+    }
+    if(USB->ISTR & USB_ISTR_CTR){
+        // EP number
+        uint8_t n = USB->ISTR & USB_ISTR_EPID;
+        // copy status register
+        uint16_t epstatus = USB->EPnR[n];
+        // copy received bytes amount
+        endpoints[n].rx_cnt = USB_BTABLE->EP[n].USB_COUNT_RX & 0x3FF; // low 10 bits is counter
+        // check direction
+        if(USB->ISTR & USB_ISTR_DIR){ // OUT interrupt - receive data, CTR_RX==1 (if CTR_TX == 1 - two pending transactions: receive following by transmit)
+            if(n == 0){ // control endpoint
+                if(epstatus & USB_EPnR_SETUP){ // setup packet -> copy data to conf_pack
+                    EP_Read(0, (uint16_t*)&setup_packet);
+                    ep0dbuflen = 0;
+                    // interrupt handler will be called later
+                }else if(epstatus & USB_EPnR_CTR_RX){ // data packet -> push received data to ep0databuf
+                    ep0dbuflen = endpoints[0].rx_cnt;
+                    EP_Read(0, (uint16_t*)&ep0databuf);
+                }
+            }
+        }
+        // call EP handler
+        if(endpoints[n].func) endpoints[n].func(endpoints[n]);
+    }
+    if(USB->ISTR & USB_ISTR_SUSP){ // suspend -> still no connection, may sleep
+        usbON = 0;
+        USB->CNTR |= USB_CNTR_FSUSP | USB_CNTR_LP_MODE;
+        USB->ISTR = ~USB_ISTR_SUSP;
+    }
+    if(USB->ISTR & USB_ISTR_WKUP){ // wakeup
+        USB->CNTR &= ~(USB_CNTR_FSUSP | USB_CNTR_LP_MODE); // clear suspend flags
+        USB->ISTR = ~USB_ISTR_WKUP;
+    }
+}
+
+/**
+ * Write data to EP buffer (called from IRQ handler)
+ * @param number - EP number
+ * @param *buf - array with data
+ * @param size - its size
+ */
+void EP_WriteIRQ(uint8_t number, const uint8_t *buf, uint16_t size){
+    uint8_t i;
+    if(size > endpoints[number].txbufsz) size = endpoints[number].txbufsz;
+    uint16_t N2 = (size + 1) >> 1;
+    // the buffer is 16-bit, so we should copy data as it would be uint16_t
+    uint16_t *buf16 = (uint16_t *)buf;
+    uint32_t *out = (uint32_t *)endpoints[number].tx_buf;
+    for(i = 0; i < N2; ++i, ++out){
+        *out = buf16[i];
+    }
+    USB_BTABLE->EP[number].USB_COUNT_TX = size;
+}
+
+/**
+ * Write data to EP buffer (called outside IRQ handler)
+ * @param number - EP number
+ * @param *buf - array with data
+ * @param size - its size
+ */
+void EP_Write(uint8_t number, const uint8_t *buf, uint16_t size){
+    EP_WriteIRQ(number, buf, size);
+    uint16_t status = KEEP_DTOG(USB->EPnR[number]);
+    // keep DTOGs, clear CTR_TX & set TX VALID to start transmission
+    USB->EPnR[number] = (status & ~(USB_EPnR_CTR_TX)) ^ USB_EPnR_STAT_TX;
+}
+
+/*
+ * Copy data from EP buffer into user buffer area
+ * @param *buf - user array for data
+ * @return amount of data read
+ */
+int EP_Read(uint8_t number, uint16_t *buf){
+    int sz = endpoints[number].rx_cnt;
+    if(!sz) return 0;
+    endpoints[number].rx_cnt = 0;
+    int n = (sz + 1) >> 1;
+    uint32_t *in = (uint32_t *)endpoints[number].rx_buf;
+    if(n){
+        for(int i = 0; i < n; ++i, ++in)
+            buf[i] = *(uint16_t*)in;
+    }
+    return sz;
+}
+

F1:F103/BMP180/usb_lib.h

@@ -0,0 +1,184 @@
+/*
+ * This file is part of the BMP180 project.
+ * Copyright 2020 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#ifndef __USB_LIB_H__
+#define __USB_LIB_H__
+
+#include <wchar.h>
+#include "usb_defs.h"
+
+#define EP0DATABUF_SIZE                 (64)
+#define LASTADDR_DEFAULT                (STM32ENDPOINTS * 8)
+
+// bmRequestType & 0x7f
+#define STANDARD_DEVICE_REQUEST_TYPE    0
+#define STANDARD_ENDPOINT_REQUEST_TYPE  2
+#define VENDOR_REQUEST_TYPE             0x40
+#define CONTROL_REQUEST_TYPE            0x21
+// bRequest, standard; for bmRequestType == 0x80
+#define GET_STATUS                      0x00
+#define GET_DESCRIPTOR                  0x06
+#define GET_CONFIGURATION               0x08
+// for bmRequestType == 0
+#define CLEAR_FEATURE                   0x01
+#define SET_FEATURE                     0x03    // unused
+#define SET_ADDRESS                     0x05
+#define SET_DESCRIPTOR                  0x07    // unused
+#define SET_CONFIGURATION               0x09
+// for bmRequestType == 0x81, 1 or 0xB2
+#define GET_INTERFACE                   0x0A    // unused
+#define SET_INTERFACE                   0x0B    // unused
+#define SYNC_FRAME                      0x0C    // unused
+#define VENDOR_REQUEST                  0x01    // unused
+
+// Class-Specific Control Requests
+#define SEND_ENCAPSULATED_COMMAND       0x00    // unused
+#define GET_ENCAPSULATED_RESPONSE       0x01    // unused
+#define SET_COMM_FEATURE                0x02    // unused
+#define GET_COMM_FEATURE                0x03    // unused
+#define CLEAR_COMM_FEATURE              0x04    // unused
+#define SET_LINE_CODING                 0x20
+#define GET_LINE_CODING                 0x21
+#define SET_CONTROL_LINE_STATE          0x22
+#define SEND_BREAK                      0x23
+
+// control line states
+#define CONTROL_DTR                     0x01
+#define CONTROL_RTS                     0x02
+
+// wValue
+#define DEVICE_DESCRIPTOR               0x100
+#define CONFIGURATION_DESCRIPTOR        0x200
+#define STRING_LANG_DESCRIPTOR          0x300
+#define STRING_MAN_DESCRIPTOR           0x301
+#define STRING_PROD_DESCRIPTOR          0x302
+#define STRING_SN_DESCRIPTOR            0x303
+#define DEVICE_QUALIFIER_DESCRIPTOR     0x600
+
+#define RX_FLAG(epstat)                 (epstat & USB_EPnR_CTR_RX)
+#define TX_FLAG(epstat)                 (epstat & USB_EPnR_CTR_TX)
+#define SETUP_FLAG(epstat)              (epstat & USB_EPnR_SETUP)
+
+// EPnR bits manipulation
+#define KEEP_DTOG_STAT(EPnR)            (EPnR & ~(USB_EPnR_STAT_RX|USB_EPnR_STAT_TX|USB_EPnR_DTOG_RX|USB_EPnR_DTOG_TX))
+#define KEEP_DTOG(EPnR)                 (EPnR & ~(USB_EPnR_DTOG_RX|USB_EPnR_DTOG_TX))
+
+// USB state: uninitialized, addressed, ready for use
+typedef enum{
+    USB_STATE_DEFAULT,
+    USB_STATE_ADDRESSED,
+    USB_STATE_CONFIGURED,
+    USB_STATE_CONNECTED
+} USB_state;
+
+// EP types
+#define EP_TYPE_BULK                    0x00
+#define EP_TYPE_CONTROL                 0x01
+#define EP_TYPE_ISO                     0x02
+#define EP_TYPE_INTERRUPT               0x03
+
+#define LANG_US (uint16_t)0x0409
+
+#define _USB_STRING_(name, str)                  \
+static const struct name \
+{                          \
+        uint8_t  bLength;                       \
+        uint8_t  bDescriptorType;               \
+        uint16_t bString[(sizeof(str) - 2) / 2]; \
+    \
+} \
+name = {sizeof(name), 0x03, str}
+
+#define _USB_LANG_ID_(name, lng_id)     \
+    \
+static const struct name \
+{         \
+        uint8_t  bLength;         \
+        uint8_t  bDescriptorType; \
+        uint16_t bString;         \
+    \
+} \
+name = {0x04, 0x03, lng_id}
+#define STRING_LANG_DESCRIPTOR_SIZE_BYTE    (4)
+
+// EP0 configuration packet
+typedef struct {
+    uint8_t bmRequestType;
+    uint8_t bRequest;
+    uint16_t wValue;
+    uint16_t wIndex;
+    uint16_t wLength;
+} config_pack_t;
+
+// endpoints state
+typedef struct{
+    uint16_t *tx_buf;           // transmission buffer address
+    uint16_t txbufsz;           // transmission buffer size
+    uint16_t *rx_buf;           // reception buffer address
+    void (*func)();             // endpoint action function
+    unsigned rx_cnt  : 10;      // received data counter
+} ep_t;
+
+// USB status & its address
+typedef struct {
+    uint8_t  USB_Status;
+    uint16_t USB_Addr;
+}usb_dev_t;
+
+typedef struct {
+    uint32_t dwDTERate;
+    uint8_t bCharFormat;
+    #define USB_CDC_1_STOP_BITS   0
+    #define USB_CDC_1_5_STOP_BITS 1
+    #define USB_CDC_2_STOP_BITS   2
+    uint8_t bParityType;
+    #define USB_CDC_NO_PARITY     0
+    #define USB_CDC_ODD_PARITY    1
+    #define USB_CDC_EVEN_PARITY   2
+    #define USB_CDC_MARK_PARITY   3
+    #define USB_CDC_SPACE_PARITY  4
+    uint8_t bDataBits;
+} __attribute__ ((packed)) usb_LineCoding;
+
+typedef struct {
+    uint8_t   bmRequestType;
+    uint8_t   bNotificationType;
+    uint16_t  wValue;
+    uint16_t  wIndex;
+    uint16_t  wLength;
+} __attribute__ ((packed)) usb_cdc_notification;
+
+extern ep_t endpoints[];
+extern usb_dev_t USB_Dev;
+extern uint8_t usbON;
+
+void USB_Init();
+void USB_ResetState();
+int EP_Init(uint8_t number, uint8_t type, uint16_t txsz, uint16_t rxsz, void (*func)());
+void EP_WriteIRQ(uint8_t number, const uint8_t *buf, uint16_t size);
+void EP_Write(uint8_t number, const uint8_t *buf, uint16_t size);
+int EP_Read(uint8_t number, uint16_t *buf);
+usb_LineCoding getLineCoding();
+
+void linecoding_handler(usb_LineCoding *lc);
+void clstate_handler(uint16_t val);
+void break_handler();
+void vendor_handler(config_pack_t *packet);
+
+#endif // __USB_LIB_H__

F1:F103/BMP280/BMP280.c

@@ -0,0 +1,472 @@
+/**
+ * Ciastkolog.pl (https://github.com/ciastkolog)
+ *
+*/
+/**
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2016 sheinz (https://github.com/sheinz)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+/*
+ * This file is part of the BMP280 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "i2c.h"
+#include "BMP280.h"
+
+//#define EBUG
+
+#ifdef EBUG
+#include "usb.h"
+#include "proto.h"
+#define DBG(x)  do{USB_send(x);}while(0)
+#else
+#define DBG(x)
+#endif
+
+#define BMP280_I2C_ADDRESS_MASK 0x76
+#define BMP280_I2C_ADDRESS_0  0x76
+#define BMP280_I2C_ADDRESS_1  0x77
+/**
+ * BMP280 registers
+ */
+#define BMP280_REG_HUM_LSB      0xFE
+#define BMP280_REG_HUM_MSB      0xFD
+#define BMP280_REG_HUM          (BMP280_REG_HUM_MSB)
+#define BMP280_REG_TEMP_XLSB    0xFC /* bits: 7-4 */
+#define BMP280_REG_TEMP_LSB     0xFB
+#define BMP280_REG_TEMP_MSB     0xFA
+#define BMP280_REG_TEMP         (BMP280_REG_TEMP_MSB)
+#define BMP280_REG_PRESS_XLSB   0xF9 /* bits: 7-4 */
+#define BMP280_REG_PRESS_LSB    0xF8
+#define BMP280_REG_PRESS_MSB    0xF7
+#define BMP280_REG_PRESSURE     (BMP280_REG_PRESS_MSB)
+#define BMP280_REG_ALLDATA      (BMP280_REG_PRESS_MSB) // all data: P, T & H
+#define BMP280_REG_CONFIG       0xF5 /* bits: 7-5 t_sb; 4-2 filter; 0 spi3w_en */
+#define BMP280_REG_CTRL         0xF4 /* bits: 7-5 osrs_t; 4-2 osrs_p; 1-0 mode */
+#define BMP280_REG_STATUS       0xF3 /* bits: 3 measuring; 0 im_update */
+#define BMP280_REG_CTRL_HUM     0xF2 /* bits: 2-0 osrs_h; */
+#define BMP280_REG_RESET        0xE0
+    #define BMP280_RESET_VALUE     0xB6
+#define BMP280_REG_ID           0xD0
+
+#define BMP280_REG_CALIBA       0x88
+#define BMP280_CALIBA_SIZE      (26)  // 26 bytes of calibration registers sequence from 0x88 to 0xa1
+#define BMP280_CALIBB_SIZE      (7)   // 7 bytes of calibration registers sequence from 0xe1 to 0xe7
+#define BMP280_REG_CALIBB       0xE1
+
+#define BMP280_MODE_FORSED      (1)  // force single measurement
+#define BMP280_MODE_NORMAL      (3)  // run continuosly
+#define BMP280_STATUS_MSRNG     (1<<3) // measuring in process
+
+static uint8_t curaddress = BMP280_I2C_ADDRESS_0;
+
+static struct {
+    // temperature
+    uint16_t dig_T1;    // 0x88 (LSB), 0x98 (MSB)
+    int16_t  dig_T2;    // ...
+    int16_t  dig_T3;
+    // pressure
+    uint16_t dig_P1;
+    int16_t  dig_P2;
+    int16_t  dig_P3;
+    int16_t  dig_P4;
+    int16_t  dig_P5;
+    int16_t  dig_P6;
+    int16_t  dig_P7;
+    int16_t  dig_P8;
+    int16_t  dig_P9;    // 0x9e, 0x9f
+    // humidity (partially calculated from EEE struct)
+    uint8_t unused;     // 0xA0
+    uint8_t dig_H1;     // 0xA1
+    int16_t dig_H2;     // --------------------
+    uint8_t dig_H3;     // only from EEE
+    uint16_t dig_H4;
+    uint16_t dig_H5;
+    int8_t dig_H6;
+    // data is ready
+    uint8_t  rdy;
+} __attribute__ ((packed)) CaliData = {0};
+
+//T: 28222 26310 50
+//P: 37780 -10748 3024 7965 -43 -7 9900 -10230 4285
+//H: 75 25601 0 334 50 30
+
+// data for humidity calibration of BME280
+static uint8_t EEE[BMP280_CALIBB_SIZE] = {0};
+
+static struct{
+    BMP280_Filter filter;       // filtering
+    BMP280_Oversampling p_os;   // oversampling for pressure
+    BMP280_Oversampling t_os;   // -//- temperature
+    BMP280_Oversampling h_os;   // -//- humidity
+    uint8_t ID;                 // identificator
+    uint8_t regctl;             // control register base value [(params.t_os << 5) | (params.p_os << 2)]
+} params = {
+    .filter = BMP280_FILTER_OFF,
+    .p_os   = BMP280_OVERS16,
+    .t_os   = BMP280_OVERS16,
+    .h_os   = BMP280_OVERS16,
+    .ID     = 0
+};
+
+static BMP280_status bmpstatus = BMP280_NOTINIT;
+
+BMP280_status BMP280_get_status(){
+    return bmpstatus;
+}
+
+// address: 0 or 1
+void BMP280_setup(uint8_t address){
+    curaddress = BMP280_I2C_ADDRESS_MASK | (address & 1);
+    bmpstatus = BMP280_NOTINIT;
+}
+
+// setters for `params`
+void BMP280_setfilter(BMP280_Filter f){
+    params.filter = f;
+}
+void BMP280_setOSt(BMP280_Oversampling os){
+    params.t_os = os;
+}
+void BMP280_setOSp(BMP280_Oversampling os){
+    params.p_os = os;
+}
+void BMP280_setOSh(BMP280_Oversampling os){
+    params.h_os = os;
+}
+
+
+/*
+// read register, @return 1 if all OK
+static int read_reg16(uint8_t reg, uint16_t *val){
+    if(I2C_OK != i2c_7bit_send_onebyte(reg, 0)) return 0;
+    if(I2C_OK != i2c_7bit_receive_twobytes((uint8_t*)val)) return 0;
+    return 1;
+}*/
+
+static int read_reg8(uint8_t reg, uint8_t *val){
+    if(I2C_OK != i2c_7bit_send_onebyte(reg, 0)) return 0;
+    if(I2C_OK != i2c_7bit_receive_onebyte(val, 1)) return 0;
+    return 1;
+}
+
+static int write_reg8(uint8_t reg, uint8_t val){
+    uint8_t d[2] = {reg, val};
+    if(I2C_OK != i2c_7bit_send(d, 2)) return 0;
+    return 1;
+}
+
+// get compensation data, return 1 if OK
+static int readcompdata(){
+    if(I2C_OK != i2c_7bit_send_onebyte(BMP280_REG_CALIBA, 0)) return 0;
+    if(I2C_OK != i2c_7bit_receive((uint8_t*)&CaliData, BMP280_CALIBA_SIZE)) return 0;
+    CaliData.rdy = 1;
+    if(params.ID == BME280_CHIP_ID){
+        if(I2C_OK == i2c_7bit_send_onebyte(BMP280_REG_CALIBB, 0) &&
+            I2C_OK == i2c_7bit_receive(EEE, BMP280_CALIBB_SIZE)){
+            CaliData.dig_H2 = (EEE[1] << 8) | EEE[0];
+            CaliData.dig_H3 = EEE[2];
+            CaliData.dig_H4 = (EEE[3] << 4) | (EEE[4] & 0x0f);
+            CaliData.dig_H5 = (EEE[5] << 4) | (EEE[4] >> 4);
+            CaliData.dig_H6 = EEE[6];
+        }
+    }
+    return 1;
+}
+
+// read compensation data & write registers
+int BMP280_init(){
+    i2c_setup();
+	i2c_set_addr7(curaddress);
+    if(!read_reg8(BMP280_REG_ID, &params.ID)) return 0;
+    DBG("Got device ID: "); DBG(u2str(params.ID)); DBG("\n");
+    if(params.ID != BMP280_CHIP_ID && params.ID != BME280_CHIP_ID){
+        DBG("Not BMP/BME\n");
+        return 0;
+    }
+    if(!write_reg8(BMP280_REG_RESET, BMP280_RESET_VALUE)){
+        DBG("Can't reset\n");
+        return 0;
+    }
+    uint8_t reg = 1;
+    while(reg & 1){
+        if(!read_reg8(BMP280_REG_STATUS, &reg)) return 0;
+    }
+    if(!readcompdata()){
+        DBG("Can't read calibration data\n");
+    }else{
+        DBG("T: "); DBG(u2str(CaliData.dig_T1)); DBG(" "); DBG(i2str(CaliData.dig_T2));
+        DBG(" "); DBG(i2str(CaliData.dig_T3));
+        DBG("\nP: "); DBG(u2str(CaliData.dig_P1)); DBG(" ");
+        DBG(i2str(CaliData.dig_P2)); DBG(" "); DBG(i2str(CaliData.dig_P3)); DBG(" ");
+        DBG(i2str(CaliData.dig_P4)); DBG(" "); DBG(i2str(CaliData.dig_P5)); DBG(" ");
+        DBG(i2str(CaliData.dig_P6)); DBG(" "); DBG(i2str(CaliData.dig_P7)); DBG(" ");
+        DBG(i2str(CaliData.dig_P8)); DBG(" "); DBG(i2str(CaliData.dig_P9));
+        DBG("\nH: "); DBG(u2str(CaliData.dig_H1)); DBG(" ");
+        if(params.ID == BME280_CHIP_ID){ // read H compensation
+            DBG(i2str(CaliData.dig_H2)); DBG(" "); DBG(u2str(CaliData.dig_H3)); DBG(" ");
+            DBG(i2str(CaliData.dig_H4)); DBG(" "); DBG(i2str(CaliData.dig_H5)); DBG(" ");
+            DBG(i2str(CaliData.dig_H6));
+        }else{DBG("not BME!");}
+        DBG("\n");
+    }
+    // write filter configuration
+    reg = params.filter << 2;
+    if(!write_reg8(BMP280_REG_CONFIG, reg)){DBG("Can't save filter settings\n");}
+    reg = (params.t_os << 5) | (params.p_os << 2); // oversampling for P/T, sleep mode
+    if(!write_reg8(BMP280_REG_CTRL, reg)){
+        DBG("Can't write settings for P/T\n");
+        return 0;
+    }
+    params.regctl = reg;
+    if(params.ID == BME280_CHIP_ID){ // write CTRL_HUM only AFTER CTRL!
+        reg = params.h_os;
+        if(!write_reg8(BMP280_REG_CTRL_HUM, reg)){
+            DBG("Can't write settings for H\n");
+            return 0;
+        }
+    }
+    return 1;
+}
+
+// @return 1 if OK, *devid -> BMP/BME
+int BMP280_read_ID(uint8_t *devid){
+    if(params.ID != BMP280_CHIP_ID && params.ID != BME280_CHIP_ID) return 0;
+    *devid = params.ID;
+    return 1;
+}
+
+// start measurement, @return 1 if all OK
+int BMP280_start(){
+    if(!CaliData.rdy || bmpstatus == BMP280_BUSY) return 0;
+    uint8_t reg = params.regctl | BMP280_MODE_FORSED;
+    if(!write_reg8(BMP280_REG_CTRL, reg)){
+        DBG("Can't write CTRL reg\n");
+        return 0;
+    }
+    bmpstatus = BMP280_BUSY;
+    return 1;
+}
+
+void BMP280_process(){
+    if(bmpstatus != BMP280_BUSY) return;
+    // BUSY state: poll data ready
+    uint8_t reg;
+    if(!read_reg8(BMP280_REG_STATUS, &reg)) return;
+    if(reg & BMP280_STATUS_MSRNG) return; // still busy
+    bmpstatus = BMP280_RDY; // data ready
+}
+
+// return T*100 degC
+static inline int32_t compTemp(int32_t adc_temp, int32_t *t_fine){
+	int32_t var1, var2;
+	var1 = ((((adc_temp >> 3) - ((int32_t) CaliData.dig_T1 << 1)))
+			* (int32_t) CaliData.dig_T2) >> 11;
+	var2 = (((((adc_temp >> 4) - (int32_t) CaliData.dig_T1)
+			* ((adc_temp >> 4) - (int32_t) CaliData.dig_T1)) >> 12)
+			* (int32_t) CaliData.dig_T3) >> 14;
+	*t_fine = var1 + var2;
+	return (*t_fine * 5 + 128) >> 8;
+}
+
+// return p*256 hPa
+static inline uint32_t compPres(int32_t adc_press, int32_t fine_temp) {
+	int64_t var1, var2, p;
+	var1 = (int64_t) fine_temp - 128000;
+	var2 = var1 * var1 * (int64_t) CaliData.dig_P6;
+	var2 = var2 + ((var1 * (int64_t) CaliData.dig_P5) << 17);
+	var2 = var2 + (((int64_t) CaliData.dig_P4) << 35);
+	var1 = ((var1 * var1 * (int64_t) CaliData.dig_P3) >> 8)
+			+ ((var1 * (int64_t) CaliData.dig_P2) << 12);
+	var1 = (((int64_t) 1 << 47) + var1) * ((int64_t) CaliData.dig_P1) >> 33;
+	if (var1 == 0){
+		return 0;  // avoid exception caused by division by zero
+	}
+	p = 1048576 - adc_press;
+	p = (((p << 31) - var2) * 3125) / var1;
+	var1 = ((int64_t) CaliData.dig_P9 * (p >> 13) * (p >> 13)) >> 25;
+	var2 = ((int64_t) CaliData.dig_P8 * p) >> 19;
+	p = ((p + var1 + var2) >> 8) + ((int64_t) CaliData.dig_P7 << 4);
+	return p;
+}
+
+// return H*1024 %
+static inline uint32_t compHum(int32_t adc_hum, int32_t fine_temp){
+	int32_t v_x1_u32r;
+	v_x1_u32r = fine_temp - (int32_t) 76800;
+	v_x1_u32r = ((((adc_hum << 14) - (((int32_t)CaliData.dig_H4) << 20)
+			- (((int32_t)CaliData.dig_H5) * v_x1_u32r)) + (int32_t)16384) >> 15)
+			* (((((((v_x1_u32r * ((int32_t)CaliData.dig_H6)) >> 10)
+					* (((v_x1_u32r * ((int32_t)CaliData.dig_H3)) >> 11)
+							+ (int32_t)32768)) >> 10) + (int32_t)2097152)
+					* ((int32_t)CaliData.dig_H2) + 8192) >> 14);
+    DBG("Step1: "); DBG(i2str(v_x1_u32r)); DBG(".. ");
+	v_x1_u32r = v_x1_u32r
+			- (((((v_x1_u32r >> 15) * (v_x1_u32r >> 15)) >> 7)
+					* ((int32_t)CaliData.dig_H1)) >> 4);
+    DBG("Step2: "); DBG(i2str(v_x1_u32r)); DBG(".. ");
+	v_x1_u32r = v_x1_u32r < 0 ? 0 : v_x1_u32r;
+	v_x1_u32r = v_x1_u32r > 419430400 ? 419430400 : v_x1_u32r;
+    DBG("Step3: "); DBG(i2str(v_x1_u32r)); DBG("\n");
+	return v_x1_u32r >> 12;
+}
+
+
+// read data & convert it
+int BMP280_getdata(int32_t *T, uint32_t *P, uint32_t *H){
+    if(bmpstatus != BMP280_RDY) return 0;
+    bmpstatus = BMP280_RELAX;
+    uint8_t datasz = 8; // amount of bytes to read
+    if(params.ID != BME280_CHIP_ID){
+        DBG("Not BME!\n");
+        if(H) *H = 0;
+        H = NULL;
+        datasz = 6;
+    }
+    uint8_t data[8];
+    if(I2C_OK != i2c_7bit_send_onebyte(BMP280_REG_ALLDATA, 0)) return 0;
+    if(I2C_OK != i2c_7bit_receive(data, datasz)) return 0;
+    int32_t p = (data[0] << 12) | (data[1] << 4) | (data[2] >> 4);
+    DBG("puncomp = "); DBG(i2str(p)); DBG("\n");
+    int32_t t = (data[3] << 12) | (data[4] << 4) | (data[5] >> 4);
+    DBG("tuncomp = "); DBG(i2str(t)); DBG("\n");
+    int32_t t_fine;
+    int32_t Temp = compTemp(t, &t_fine);
+    DBG("tfine = "); DBG(i2str(t_fine)); DBG("\n");
+    if(T) *T = Temp;
+    if(P){
+        float fp = compPres(p, t_fine) / 256.;
+        *P = fp;// * 100.;
+    }
+    if(H){
+        int32_t h = (data[6] << 8) | data[7];
+        DBG("huncomp = "); DBG(i2str(h)); DBG("\n");
+        float fh = compHum(h, t_fine)/1024.;
+        *H = fh * 100.;
+    }
+    return 1;
+}
+
+#if 0
+/*
+ * start themperature reading @return 0 if all OK
+ */
+int BMP280_cmdT(){
+	const uint8_t cmd[2] = {0x03, 0x11};
+	if(state != RELAX){
+		return 1;
+	}
+    bmpstatus = BMP280_BUSY;
+	i2c_status st = i2c_7bit_send(cmd, 2);
+	if(st != I2C_OK){
+        bmpstatus = BMP280_ERR;
+		return 1;
+	}
+    DBG("Wait for T\n");
+	state = WAITFORT;
+    return 0;
+}
+
+/*
+ * start humidity reading @return 0 if all OK
+ */
+int BMP280_cmdH(){
+	const uint8_t cmd[2] = {0x03, 0x01};
+	if(state != RELAX){
+		return 1;
+	}
+    bmpstatus = BMP280_BUSY;
+	i2c_status st = i2c_7bit_send(cmd, 2);
+	if(st != I2C_OK){
+        bmpstatus = BMP280_ERR;
+		return 1;
+	}
+	state = WAITFORH;
+    DBG("Wait for H\n");
+    return 0;
+}
+
+int32_t BMP280_getT(){ // T*10
+    if(bmpstatus != BMP280_TRDY) return -5000;
+    DBG("TH="); DBG(u2str(TH)); DBG("\n");
+    TH >>= 2;
+    uint32_t d = (TH*10)/32 - 500;
+    bmpstatus = BMP280_RELAX;
+    return d;
+}
+uint32_t BMP280_getH(){ // hum * 10
+    if(bmpstatus != BMP280_HRDY) return 5000;
+    TH >>= 4;
+    uint32_t d = (TH*10)/16 - 240;
+    bmpstatus = BMP280_RELAX;
+    return d;
+}
+
+/*
+ * process state machine
+ */
+void BMP280_process(){
+	uint8_t b, d[2];
+	i2c_status st;
+	if(state == RELAX) return;
+	if(state == WAITFORH || state == WAITFORT){ // poll RDY
+        DBG("Poll\n");
+		if((st = i2c_7bit_send_onebyte(0, 0)) == I2C_OK){
+            DBG("0 sent\n");
+			if(i2c_7bit_receive_onebyte(&b, 1) == I2C_OK){
+                DBG("received: "); DBG(u2str(b)); DBG("\n");
+				if(b) return; // !RDY
+                if((st = i2c_7bit_send_onebyte(1, 0)) == I2C_OK){
+                    DBG("sent 1\n");
+                    if((st = i2c_7bit_receive_twobytes(d)) == I2C_OK){
+                        DBG("got data: ");
+                        DBG(u2str(d[0])); DBG(" "); DBG(u2str(d[1])); DBG("\n");
+                        bmpstatus = (state == WAITFORH) ? BMP280_HRDY : BMP280_TRDY;
+                        TH = (d[0]<<8) | d[1];
+                    }
+                }
+				state = RELAX;
+				if(st != I2C_OK){
+					bmpstatus = BMP280_ERR;
+				}
+			}
+		}else{
+			state = RELAX;
+            bmpstatus = BMP280_ERR;
+		}
+	}
+}
+#endif

F1:F103/BMP280/BMP280.h

@@ -0,0 +1,96 @@
+/**
+ * Ciastkolog.pl (https://github.com/ciastkolog)
+ *
+*/
+/**
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2016 sheinz (https://github.com/sheinz)
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+/*
+ * This file is part of the BMP280 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#ifndef BMP280_H__
+#define BMP280_H__
+
+#include <stm32f1.h>
+
+#define BMP280_CHIP_ID  0x58
+#define BME280_CHIP_ID  0x60
+
+typedef enum{ // K for filtering: next = [prev*(k-1) + data_ADC]/k
+    BMP280_FILTER_OFF = 0, // k=1, no filtering
+    BMP280_FILTER_2   = 1, // k=2, 2 samples to reach >75% of data_ADC
+    BMP280_FILTER_4   = 2, // k=4, 5 samples
+    BMP280_FILTER_8   = 3, // k=8, 11 samples
+    BMP280_FILTER_16  = 4, // k=16, 22 samples
+    BMP280_FILTERMAX
+} BMP280_Filter;
+
+typedef enum{ // Number of oversampling
+    BMP280_NOMEASUR = 0,
+    BMP280_OVERS1   = 1,
+    BMP280_OVERS2   = 2,
+    BMP280_OVERS4   = 3,
+    BMP280_OVERS8   = 4,
+    BMP280_OVERS16  = 5,
+    BMP280_OVERSMAX
+} BMP280_Oversampling;
+
+typedef enum{
+    BMP280_NOTINIT,     // wasn't inited
+    BMP280_BUSY,        // measurement in progress
+    BMP280_ERR,         // error in I2C
+    BMP280_RELAX,       // relaxed state
+    BMP280_RDY,         // data ready - can get it
+} BMP280_status;
+
+
+void BMP280_setup(uint8_t address);
+int BMP280_init();
+void BMP280_setfilter(BMP280_Filter f);
+void BMP280_setOSt(BMP280_Oversampling os);
+void BMP280_setOSp(BMP280_Oversampling os);
+void BMP280_setOSh(BMP280_Oversampling os);
+int BMP280_read_ID(uint8_t *devid);
+BMP280_status BMP280_get_status();
+int BMP280_start();
+void BMP280_process();
+int BMP280_getdata(int32_t *T, uint32_t *P, uint32_t *H);
+
+
+#endif // BMP280_H__

F1:F103/BMP280/Makefile

@@ -0,0 +1,139 @@
+BINARY		= BMP280
+BOOTPORT	?= /dev/ttyUSB0
+BOOTSPEED	?= 115200
+# MCU FAMILY
+FAMILY		?= F1
+# MCU code
+MCU			?= F103x8
+# density (stm32f10x.h, lines 70-84)
+DENSITY 	?= MD
+# change this linking script depending on particular MCU model,
+LDSCRIPT	?= stm32f103x8.ld
+# debug
+#DEFS		= -DEBUG
+
+INDEPENDENT_HEADERS=
+
+FP_FLAGS	?= -msoft-float -mfloat-abi=soft
+ASM_FLAGS	?= -mthumb -mcpu=cortex-m3 -mfix-cortex-m3-ldrd
+ARCH_FLAGS	= $(ASM_FLAGS) $(FP_FLAGS)
+
+###############################################################################
+# Executables
+#PREFIX		?= arm-none-eabi
+# gcc from arm web site 
+PREFIX		?= /opt/bin/arm-none-eabi
+TOOLCHLIB	?= /opt/arm-none-eabi/lib
+RM			:= rm -f
+RMDIR		:= rmdir
+CC			:= $(PREFIX)-gcc
+# don't replace ld with gcc: the binary size would be much greater!!
+LD			:= $(PREFIX)-ld
+AR			:= $(PREFIX)-ar
+AS			:= $(PREFIX)-as
+SIZE 		:= $(PREFIX)-size
+OBJCOPY		:= $(PREFIX)-objcopy
+OBJDUMP		:= $(PREFIX)-objdump
+GDB			:= $(PREFIX)-gdb
+STFLASH		:= $(shell which st-flash)
+STBOOT		:= $(shell which stm32flash)
+DFUUTIL		:= $(shell which dfu-util)
+
+###############################################################################
+# Source files
+OBJDIR 		= mk
+SRC			:= $(wildcard *.c)
+OBJS		:= $(addprefix $(OBJDIR)/, $(SRC:%.c=%.o))
+STARTUP		= $(OBJDIR)/startup.o
+OBJS 		+= $(STARTUP)
+# dependencies: we need them to recompile files if their headers-dependencies changed
+DEPS		:= $(OBJS:.o=.d)
+
+INC_DIR ?= ../inc
+
+INCLUDE 	:= -I$(INC_DIR)/Fx -I$(INC_DIR)/cm
+LIB_DIR		:= $(INC_DIR)/ld
+
+###############################################################################
+# C flags
+CFLAGS		+= -O2 -g -D__thumb2__=1 -MD
+CFLAGS		+= -Wall -Werror -Wextra -Wshadow 
+CFLAGS		+= -fno-common -ffunction-sections -fdata-sections -fno-stack-protector
+CFLAGS		+=  $(ARCH_FLAGS)
+
+###############################################################################
+# Linker flags
+LDFLAGS		+= -nostartfiles --static -nostdlibs 
+LDFLAGS		+= -L$(LIB_DIR) -L$(TOOLCHLIB)
+LDFLAGS		+= -T$(LDSCRIPT)
+
+###############################################################################
+# Used libraries
+LDLIBS		+=  -lc $(shell $(CC) $(CFLAGS) -print-libgcc-file-name)
+
+DEFS		+= -DSTM32$(FAMILY) -DSTM32$(MCU) -DSTM32F10X_$(DENSITY)
+
+ELF		:= $(OBJDIR)/$(BINARY).elf
+LIST	:= $(OBJDIR)/$(BINARY).list
+BIN		:= $(BINARY).bin
+HEX		:= $(BINARY).hex
+
+all: bin list size
+
+elf: $(ELF)
+bin: $(BIN)
+hex: $(HEX)
+list: $(LIST)
+
+ifneq ($(MAKECMDGOALS),clean)
+-include $(DEPS)
+endif
+
+$(OBJDIR):
+	mkdir $(OBJDIR)
+
+$(STARTUP): $(INC_DIR)/startup/vector.c
+	$(CC) $(CFLAGS) $(DEFS) $(INCLUDE) -o $@ -c $<
+
+$(OBJDIR)/%.o: %.c
+	@echo "  CC      $<"
+	$(CC) $(CFLAGS) $(DEFS) $(INCLUDE) -o $@ -c $<
+
+$(BIN): $(ELF)
+	@echo "  OBJCOPY $(BIN)"
+	$(OBJCOPY) -Obinary $(ELF) $(BIN)
+
+$(HEX): $(ELF)
+	@echo "  OBJCOPY $(HEX)"
+	$(OBJCOPY) -Oihex $(ELF) $(HEX)
+
+$(LIST): $(ELF)
+	@echo "  OBJDUMP $(LIST)"
+	$(OBJDUMP) -S $(ELF) > $(LIST)
+
+$(ELF): $(OBJDIR) $(OBJS)
+	@echo "  LD      $(ELF)"
+	$(LD) $(LDFLAGS) $(OBJS) $(LDLIBS) -o $(ELF)
+
+size: $(ELF)
+	$(SIZE) $(ELF)    
+
+clean:
+	@echo "  CLEAN"
+	$(RM) $(OBJS) $(DEPS) $(ELF) $(HEX) $(LIST)
+	@rmdir $(OBJDIR) 2>/dev/null || true
+
+
+flash: $(BIN)
+	@echo "  FLASH  $(BIN)"
+	$(STFLASH) write $(BIN) 0x8000000
+
+boot: $(BIN)
+	@echo "  LOAD $(BIN) through bootloader"
+	$(STBOOT) -b$(BOOTSPEED) $(BOOTPORT) -w $(BIN)
+
+dfuboot: $(BIN)
+	@echo "  LOAD  $(BIN) THROUGH DFU"
+	$(DFUUTIL) -a0 -D $(BIN) -s 0x08000000
+
+.PHONY: clean flash boot

F1:F103/BMP280/Readme

@@ -0,0 +1,2 @@
+Work with I2C temperature/pressure sensor BMP280 and temp/pres/humidity sensor BME280
+

F1:F103/BMP280/dewpoint.c

@@ -0,0 +1,74 @@
+/*
+ * This file is part of the BMP280 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "dewpoint.h"
+#include "usb.h"
+#include "proto.h"
+
+#define NKNOTS  (32)
+const uint16_t X[NKNOTS] = {1, 2, 3, 4, 5, 6, 7, 8, 10, 12, 14, 16, 19, 22, 29, 37, 47, 59, 72, 87, 104,
+                            123, 145, 171, 200, 232, 267, 348, 443, 555, 684, 832};
+const float Y[NKNOTS] = {-6.90776, -6.21461, -5.80914, -5.52146, -5.29832, -5.116, -4.96185, -4.82831,
+                         -4.60517, -4.42285, -4.2687, -4.13517, -3.96332, -3.81671, -3.54046, -3.29684,
+                         -3.05761, -2.83022, -2.63109, -2.44185, -2.26336, -2.09557, -1.93102, -1.76609,
+                         -1.60944, -1.46102, -1.32051, -1.05555, -0.814186, -0.588787, -0.379797, -0.183923};
+const float K[NKNOTS] = {0.693147, 0.405465, 0.287682, 0.223144, 0.182322, 0.154151, 0.133531, 0.111572,
+                         0.0911608, 0.0770753, 0.0667657, 0.0572834, 0.0488678, 0.0394648, 0.0304528,
+                         0.023923, 0.0189492, 0.0153176, 0.0126161, 0.010499, 0.00883123, 0.00747952,
+                         0.00634345, 0.00540186, 0.00463813, 0.00401461, 0.00327103, 0.00254071,
+                         0.00201249, 0.00162008, 0.00132348, 0.00109478};
+
+float ln(uint16_t RH){
+    // find interval
+    int idx = (NKNOTS)/2, left = 0, right = NKNOTS-1; // left, right, middle
+    while(idx > left && idx < right){
+        uint16_t midval = X[idx];
+        if(RH < midval){
+            if(idx == 0) break;
+            if(RH > X[idx-1]){ // found
+                --idx;
+                break;
+            }
+            right = idx - 1;
+            idx = (left + right)/2;
+        }else{
+            if(RH < X[idx+1]) break;  // found
+            left = idx + 1;
+            idx = (left + right)/2;
+        }
+    }
+    if(idx < 0) idx = 0;
+    else if(idx > NKNOTS-1) idx = NKNOTS - 1;
+    //USB_send("idx="); USB_send(u2str(idx)); USB_send("\n");
+    float l = Y[idx] + K[idx]*(RH - X[idx]);
+#undef NKNOTS
+    return l;
+}
+
+/**
+ * @brief dewpoint calculate dew point (*10degrC)
+ * @param T - temperature (*10degrC)
+ * @param H - rel. humidity (*10%)
+ * @return dewpoint
+ */
+int32_t dewpoint(int32_t T, uint32_t H){
+    float gamma = 17.27 * T / (2377 + T);
+    gamma += ln(H);
+    float d = 2377 * gamma / (17.27 - gamma);
+    return (int32_t)d;
+}

F1:F103/BMP280/dewpoint.h

@@ -0,0 +1,22 @@
+/*
+ * This file is part of the BMP280 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stm32f1.h>
+
+float ln(uint16_t RH);
+int32_t dewpoint(int32_t T, uint32_t H);

F1:F103/BMP280/hardware.c

@@ -0,0 +1,48 @@
+/*
+ * This file is part of the BMP280 project.
+ * Copyright 2020 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "hardware.h"
+
+static inline void gpio_setup(){
+    // Enable clocks to the GPIO subsystems (PB for ADC), turn on AFIO clocking to disable SWD/JTAG
+    RCC->APB2ENR |= RCC_APB2ENR_IOPAEN | RCC_APB2ENR_IOPCEN | RCC_APB2ENR_AFIOEN;
+    // turn off SWJ/JTAG
+//    AFIO->MAPR = AFIO_MAPR_SWJ_CFG_DISABLE;
+    AFIO->MAPR = AFIO_MAPR_SWJ_CFG_JTAGDISABLE; // for PA15
+    // Set led as opendrain output
+    GPIOC->CRH |= CRH(13, CNF_ODOUTPUT|MODE_SLOW);
+    // USB pullup (PA15) - pushpull output
+    GPIOA->CRH = CRH(15, CNF_PPOUTPUT|MODE_SLOW);
+}
+
+void hw_setup(){
+    gpio_setup();
+}
+
+void iwdg_setup(){
+    uint32_t tmout = 16000000;
+    RCC->CSR |= RCC_CSR_LSION;
+    while((RCC->CSR & RCC_CSR_LSIRDY) != RCC_CSR_LSIRDY){if(--tmout == 0) break;} /* (2) */
+    IWDG->KR = IWDG_START;
+    IWDG->KR = IWDG_WRITE_ACCESS;
+    IWDG->PR = IWDG_PR_PR_1;
+    IWDG->RLR = 1250;
+    tmout = 16000000;
+    while(IWDG->SR){if(--tmout == 0) break;}
+    IWDG->KR = IWDG_REFRESH;
+}

F1:F103/BMP280/hardware.h

@@ -0,0 +1,43 @@
+/*
+ * This file is part of the BMP280 project.
+ * Copyright 2020 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#ifndef __HARDWARE_H__
+#define __HARDWARE_H__
+
+#include "stm32f1.h"
+
+// LED0 - PC13 (bluepill), blinking each second
+#define LED0_port   GPIOC
+#define LED0_pin    (1<<13)
+
+// USB pullup (not present in bluepill, should be soldered) - PA15
+#define USBPU_port  GPIOA
+#define USBPU_pin   (1<<15)
+#define USBPU_ON()  pin_set(USBPU_port, USBPU_pin)
+#define USBPU_OFF() pin_clear(USBPU_port, USBPU_pin)
+
+#define LED_blink(x)    pin_toggle(x ## _port, x ## _pin)
+#define LED_on(x)       pin_clear(x ## _port, x ## _pin)
+#define LED_off(x)      pin_set(x ## _port, x ## _pin)
+
+void hw_setup();
+void iwdg_setup();
+
+
+#endif // __HARDWARE_H__

F1:F103/BMP280/i2c.c

@@ -0,0 +1,236 @@
+/*
+ * This file is part of the BMP280 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "hardware.h"
+#include "i2c.h"
+
+#ifdef EBUG
+#include "usb.h"
+#include "proto.h"
+#define DBG(x)  do{USB_send(x);}while(0)
+#else
+#define DBG(x)
+#endif
+
+extern volatile uint32_t Tms;
+
+// current addresses for read/write (should be set with i2c_set_addr7)
+static uint8_t addr7r = 0, addr7w = 0;
+
+/*
+ * PB10/PB6 - I2C_SCL, PB11/PB7 - I2C_SDA or remap @ PB8 & PB9
+ */
+void i2c_setup(){
+    I2C1->CR1 = 0;
+    I2C1->SR1 = 0;
+    RCC->APB2ENR |= RCC_APB2ENR_IOPBEN;
+    GPIOB->CRL = (GPIOB->CRL & ~(GPIO_CRL_CNF6 | GPIO_CRL_CNF7)) |
+            CRL(6, CNF_AFOD | MODE_NORMAL) | CRL(7, CNF_AFOD | MODE_NORMAL);
+    RCC->APB1ENR |= RCC_APB1ENR_I2C1EN;
+    I2C1->CR2 = 8; // FREQR=8MHz, T=125ns
+    I2C1->TRISE = 9; // (9-1)*125 = 1mks
+    I2C1->CCR = 40; // normal mode, 8MHz/2/40 = 100kHz
+    I2C1->CR1 |= I2C_CR1_PE; // enable periph
+}
+
+void i2c_set_addr7(uint8_t addr){
+	addr7w = addr << 1;
+	addr7r = addr7w | 1;
+}
+
+// wait for event evt no more than 2 ms
+#define I2C_WAIT(evt)  do{ register uint32_t wait4 = Tms + 2;   \
+		while(Tms < wait4 && !(evt)) IWDG->KR = IWDG_REFRESH;   \
+		if(!(evt)){ret = I2C_TMOUT; goto eotr;}}while(0)
+// wait for !busy
+#define I2C_LINEWAIT() do{ register uint32_t wait4 = Tms + 2;                   \
+    while(Tms < wait4 && (I2C1->SR2 & I2C_SR2_BUSY)) IWDG->KR = IWDG_REFRESH;   \
+    if(I2C1->SR2 & I2C_SR2_BUSY){I2C1->CR1 |= I2C_CR1_SWRST; return I2C_LINEBUSY;}\
+    }while(0)
+
+// start writing
+static i2c_status i2c_7bit_startw(){
+    i2c_status ret = I2C_LINEBUSY;
+    DBG("SR1="); DBG(u2str(I2C1->SR1)); DBG("\n");
+    DBG("CR1="); DBG(u2str(I2C1->CR1)); DBG("\n");
+    DBG("CR2="); DBG(u2str(I2C1->CR2)); DBG("\n");
+    if(I2C1->CR1 != I2C_CR1_PE) i2c_setup();
+    if(I2C1->SR1) I2C1->SR1 = 0; // clear NACK and other problems
+    (void) I2C1->SR2;
+    I2C_LINEWAIT();
+    DBG("linew\n");
+    I2C1->CR1 |= I2C_CR1_START;             // generate start sequence
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_SB);       // wait for SB
+    DBG("SB\n");
+    (void) I2C1->SR1;                       // clear SB
+    I2C1->DR = addr7w;                      // set address
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_ADDR);     // wait for ADDR flag (timeout @ NACK)
+    DBG("ADDR\n");
+    if(I2C1->SR1 & I2C_SR1_AF){             // NACK
+        return I2C_NACK;
+    }
+    DBG("ACK\n");
+    (void) I2C1->SR2;                       // clear ADDR
+    ret = I2C_OK;
+eotr:
+    return ret;
+}
+
+/**
+ * send one byte in 7bit address mode
+ * @param data - data to write
+ * @param stop - ==1 to send stop event
+ * @return status
+ */
+i2c_status i2c_7bit_send_onebyte(uint8_t data, uint8_t stop){
+    i2c_status ret = i2c_7bit_startw();
+    if(ret != I2C_OK){
+        I2C1->CR1 |= I2C_CR1_STOP;
+        goto eotr;
+    }
+    I2C1->DR = data;                        // init data send register
+    DBG("TxE\n");
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_TXE);      // wait for TxE (timeout when NACK)
+    ret = I2C_OK;
+    DBG("OK\n");
+    if(stop){
+        I2C_WAIT(I2C1->SR1 & I2C_SR1_BTF);  // wait for BTF
+        DBG("BTF\n");
+    }
+eotr:
+    if(stop){
+        I2C1->CR1 |= I2C_CR1_STOP;          // generate stop event
+    }
+    return ret;
+}
+
+// send data array
+i2c_status i2c_7bit_send(const uint8_t *data, int datalen){
+    i2c_status ret = i2c_7bit_startw();
+    if(ret != I2C_OK){
+        I2C1->CR1 |= I2C_CR1_STOP;
+        goto eotr;
+    }
+    for(int i = 0; i < datalen; ++i){
+        I2C1->DR = data[i];
+        I2C_WAIT(I2C1->SR1 & I2C_SR1_TXE);
+    }
+    ret = I2C_OK;
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_BTF);
+eotr:
+    I2C1->CR1 |= I2C_CR1_STOP;
+    return ret;
+}
+
+i2c_status i2c_7bit_receive_onebyte(uint8_t *data, uint8_t stop){
+    i2c_status ret = I2C_LINEBUSY;
+    //I2C_LINEWAIT();
+    I2C1->CR1 |= I2C_CR1_START;             // generate start sequence
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_SB);       // wait for SB
+    DBG("Rx SB\n");
+    (void) I2C1->SR1;                       // clear SB
+    I2C1->DR = addr7r;                      // set address
+    DBG("Rx addr\n");
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_ADDR);     // wait for ADDR flag
+    DBG("Rx ack\n");
+    I2C1->CR1 &= ~I2C_CR1_ACK;              // clear ACK
+    if(I2C1->SR1 & I2C_SR1_AF){             // NACK
+        DBG("Rx nak\n");
+        ret = I2C_NACK;
+        goto eotr;
+    }
+    (void) I2C1->SR2;                       // clear ADDR
+    DBG("Rx stop\n");
+    if(stop) I2C1->CR1 |= I2C_CR1_STOP;     // program STOP
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_RXNE);     // wait for RxNE
+    DBG("Rx OK\n");
+    *data = I2C1->DR;                       // read data & clear RxNE
+    ret = I2C_OK;
+eotr:
+    return ret;
+}
+
+i2c_status i2c_7bit_receive_twobytes(uint8_t *data){
+    i2c_status ret = I2C_LINEBUSY;
+    //I2C_LINEWAIT();
+    I2C1->CR1 |= I2C_CR1_START | I2C_CR1_POS | I2C_CR1_ACK; // generate start sequence, set pos & ack
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_SB);       // wait for SB
+    DBG("2 Rx sb\n");
+    (void) I2C1->SR1;                       // clear SB
+    I2C1->DR = addr7r;                      // set address
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_ADDR);     // wait for ADDR flag
+    DBG("2 ADDR\n");
+    if(I2C1->SR1 & I2C_SR1_AF){             // NACK
+        ret = I2C_NACK;
+        goto eotr;
+    }
+    DBG("2 ACK\n");
+    (void) I2C1->SR2;                       // clear ADDR
+    I2C1->CR1 &= ~I2C_CR1_ACK;              // clear ACK
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_BTF);      // wait for BTF
+    DBG("2 BTF\n");
+    I2C1->CR1 |= I2C_CR1_STOP;              // program STOP
+    *data++ = I2C1->DR; *data = I2C1->DR;   // read data & clear RxNE
+    ret = I2C_OK;
+eotr:
+    return ret;
+}
+
+// receive any amount of bytes
+i2c_status i2c_7bit_receive(uint8_t *data, uint16_t nbytes){
+    if(nbytes == 0) return I2C_HWPROBLEM;
+    I2C1->SR1 = 0; // clear previous NACK flag & other error flags
+    if(nbytes == 1) return i2c_7bit_receive_onebyte(data, 1);
+    else if(nbytes == 2) return i2c_7bit_receive_twobytes(data);
+    i2c_status ret = I2C_LINEBUSY;
+    //I2C_LINEWAIT();
+    I2C1->CR1 |= I2C_CR1_START | I2C_CR1_ACK; // generate start sequence, set pos & ack
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_SB);       // wait for SB
+    DBG("got SB\n");
+    (void) I2C1->SR1;                       // clear SB
+    I2C1->DR = addr7r;                      // set address
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_ADDR);     // wait for ADDR flag
+    DBG("send addr\n");
+    if(I2C1->SR1 & I2C_SR1_AF){             // NACK
+        DBG("NACKed\n");
+        ret = I2C_NACK;
+        goto eotr;
+    }
+    DBG("ACKed\n");
+    (void) I2C1->SR2;                       // clear ADDR
+    for(uint16_t x = nbytes - 3; x > 0; --x){
+        I2C_WAIT(I2C1->SR1 & I2C_SR1_RXNE); // wait next byte
+        *data++ = I2C1->DR;                 // get data
+    }
+    DBG("three left\n");
+    // three bytes remain to be read
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_RXNE);     // wait dataN-2
+    DBG("dataN-2\n");
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_BTF);      // wait for BTF
+    DBG("BTF\n");
+    I2C1->CR1 &= ~I2C_CR1_ACK;              // clear ACK
+    *data++ = I2C1->DR;                     // read dataN-2
+    I2C1->CR1 |= I2C_CR1_STOP;              // program STOP
+    *data++ = I2C1->DR;                     // read dataN-1
+    I2C_WAIT(I2C1->SR1 & I2C_SR1_RXNE);     // wait next byte
+    *data = I2C1->DR;                       // read dataN
+    DBG("got it\n");
+    ret = I2C_OK;
+eotr:
+    return ret;
+}

F1:F103/BMP280/i2c.h

@@ -0,0 +1,41 @@
+/*
+ * This file is part of the BMP280 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+#ifndef I2C_H__
+
+#include <stm32f1.h>
+
+typedef enum{
+	I2C_OK = 0,
+	I2C_LINEBUSY,
+	I2C_TMOUT,
+	I2C_NOADDR,
+	I2C_NACK,
+	I2C_HWPROBLEM,
+} i2c_status;
+
+void i2c_setup();
+void i2c_set_addr7(uint8_t addr);
+i2c_status i2c_7bit_send_onebyte(uint8_t data, uint8_t stop);
+i2c_status i2c_7bit_send(const uint8_t *data, int datalen);
+i2c_status i2c_7bit_receive_onebyte(uint8_t *data, uint8_t stop);
+i2c_status i2c_7bit_receive_twobytes(uint8_t *data);
+i2c_status i2c_7bit_receive(uint8_t *data, uint16_t nbytes);
+
+#define I2C_H__
+#endif // I2C_H__

F1:F103/BMP280/main.c

@@ -0,0 +1,115 @@
+/*
+ * This file is part of the BMP280 project.
+ * Copyright 2020 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "BMP280.h"
+#include "dewpoint.h"
+#include "hardware.h"
+#include "proto.h"
+#include "usb.h"
+#include "usb_lib.h"
+
+#define USBBUFSZ    127
+
+volatile uint32_t Tms = 0;
+
+/* Called when systick fires */
+void sys_tick_handler(void){
+    ++Tms;
+}
+
+// usb getline
+static char *get_USB(){
+    static char tmpbuf[USBBUFSZ+1], *curptr = tmpbuf;
+    static int rest = USBBUFSZ;
+    int x = USB_receive(curptr);
+    curptr[x] = 0;
+    if(!x) return NULL;
+    if(curptr[x-1] == '\n'){
+        curptr = tmpbuf;
+        rest = USBBUFSZ;
+        return tmpbuf;
+    }
+    curptr += x; rest -= x;
+    if(rest <= 0){ // buffer overflow
+        curptr = tmpbuf;
+        rest = USBBUFSZ;
+        USB_send("USB buffer overflow\n");
+    }
+    return NULL;
+}
+
+static void showd(int32_t mT, int32_t mH){
+    USB_send("Dewpoint=");
+    USB_send(i2str(dewpoint(mT, mH)));
+    USB_send("*10degrC\n");
+}
+
+int main(void){
+    uint32_t lastT = 0;
+    sysreset();
+    StartHSE();
+    hw_setup();
+    SysTick_Config(72000);
+
+    RCC->CSR |= RCC_CSR_RMVF; // remove reset flags
+
+    USBPU_OFF();
+    USB_setup();
+    iwdg_setup();
+    USBPU_ON();
+
+    while (1){
+        IWDG->KR = IWDG_REFRESH; // refresh watchdog
+        if(lastT > Tms || Tms - lastT > 499){
+            LED_blink(LED0);
+            lastT = Tms;
+        }
+        usb_proc();
+        BMP280_process();
+        BMP280_status s = BMP280_get_status();
+        if(s == BMP280_RDY){ // data ready - get it
+            int32_t T;
+            uint32_t P, H;
+            if(BMP280_getdata(&T, &P, &H)){
+                USB_send("T="); USB_send(i2str(T)); USB_send(" (*100degC)\nP=");
+                USB_send(u2str(P)); USB_send(" (Pa) or ");
+                float mm = P*0.0750062;
+                USB_send(u2str(mm)); USB_send(" (*10mmHg)\n");
+                if(H){
+                    USB_send("H="); USB_send(u2str(H)); USB_send(" (*100%)\n");
+                    showd(T/10, H/10);
+                }
+            }else USB_send("Can't read data\n");
+        }else if(s == BMP280_ERR){
+            USB_send("Error in measurement\n");
+            BMP280_init();
+        }
+
+        char *txt, *ans;
+        if((txt = get_USB())){
+            IWDG->KR = IWDG_REFRESH;
+            ans = (char*)parse_cmd(txt);
+            if(ans){
+                uint16_t l = 0; char *p = ans;
+                while(*p++) l++;
+                USB_send(ans);
+            }
+        }
+    }
+    return 0;
+}

F1:F103/BMP280/proto.c

@@ -0,0 +1,282 @@
+/*
+ * This file is part of the BMP280 project.
+ * Copyright 2020 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "BMP280.h"
+#include "dewpoint.h"
+#include "proto.h"
+#include "usb.h"
+
+extern volatile uint32_t Tms;
+
+char *omit_spaces(const char *buf){
+    while(*buf){
+        if(*buf > ' ') break;
+        ++buf;
+    }
+    return (char*)buf;
+}
+
+// In case of overflow return `buf` and N==0xffffffff
+// read decimal number & return pointer to next non-number symbol
+static char *getdec(const char *buf, uint32_t *N){
+    char *start = (char*)buf;
+    uint32_t num = 0;
+    while(*buf){
+        char c = *buf;
+        if(c < '0' || c > '9'){
+            break;
+        }
+        if(num > 429496729 || (num == 429496729 && c > '5')){ // overflow
+            *N = 0xffffff;
+            return start;
+        }
+        num *= 10;
+        num += c - '0';
+        ++buf;
+    }
+    *N = num;
+    return (char*)buf;
+}
+// read hexadecimal number (without 0x prefix!)
+static char *gethex(const char *buf, uint32_t *N){
+    char *start = (char*)buf;
+    uint32_t num = 0;
+    while(*buf){
+        char c = *buf;
+        uint8_t M = 0;
+        if(c >= '0' && c <= '9'){
+            M = '0';
+        }else if(c >= 'A' && c <= 'F'){
+            M = 'A' - 10;
+        }else if(c >= 'a' && c <= 'f'){
+            M = 'a' - 10;
+        }
+        if(M){
+            if(num & 0xf0000000){ // overflow
+                *N = 0xffffff;
+                return start;
+            }
+            num <<= 4;
+            num += c - M;
+        }else{
+            break;
+        }
+        ++buf;
+    }
+    *N = num;
+    return (char*)buf;
+}
+// read octal number (without 0 prefix!)
+static char *getoct(const char *buf, uint32_t *N){
+    char *start = (char*)buf;
+    uint32_t num = 0;
+    while(*buf){
+        char c = *buf;
+        if(c < '0' || c > '7'){
+            break;
+        }
+        if(num & 0xe0000000){ // overflow
+            *N = 0xffffff;
+            return start;
+        }
+        num <<= 3;
+        num += c - '0';
+        ++buf;
+    }
+    *N = num;
+    return (char*)buf;
+}
+// read binary number (without b prefix!)
+static char *getbin(const char *buf, uint32_t *N){
+    char *start = (char*)buf;
+    uint32_t num = 0;
+    while(*buf){
+        char c = *buf;
+        if(c < '0' || c > '1'){
+            break;
+        }
+        if(num & 0x80000000){ // overflow
+            *N = 0xffffff;
+            return start;
+        }
+        num <<= 1;
+        if(c == '1') num |= 1;
+        ++buf;
+    }
+    *N = num;
+    return (char*)buf;
+}
+
+/**
+ * @brief getnum - read uint32_t from string (dec, hex or bin: 127, 0x7f, 0b1111111)
+ * @param buf - buffer with number and so on
+ * @param N   - the number read
+ * @return pointer to first non-number symbol in buf
+ *      (if it is == buf, there's no number or if *N==0xffffffff there was overflow)
+ */
+char *getnum(const char *txt, uint32_t *N){
+    char *nxt = NULL;
+    char *s = omit_spaces(txt);
+    if(*s == '0'){ // hex, oct or 0
+        if(s[1] == 'x' || s[1] == 'X'){ // hex
+            nxt = gethex(s+2, N);
+            if(nxt == s+2) nxt = (char*)txt;
+        }else if(s[1] > '0'-1 && s[1] < '8'){ // oct
+            nxt = getoct(s+1, N);
+            if(nxt == s+1) nxt = (char*)txt;
+        }else{ // 0
+            nxt = s+1;
+            *N = 0;
+        }
+    }else if(*s == 'b' || *s == 'B'){
+        nxt = getbin(s+1, N);
+        if(nxt == s+1) nxt = (char*)txt;
+    }else{
+        nxt = getdec(s, N);
+        if(nxt == s) nxt = (char*)txt;
+    }
+    return nxt;
+}
+
+const char* helpmsg =
+    "'0/1' - reset I2C with devADDR 0/1\n"
+    "'Fx'- set filter to x (0..4)\n"
+    "'I' - read chip ID (after init)\n"
+    "'M' - start measurements\n"
+    "'N' - read number (0..1000) and show its ln\n"
+    "'Ovx' - set oversampling of v(t,h or p) to x(0..5)\n"
+    "'R' - software reset\n"
+    "'W' - test watchdog\n"
+;
+
+const char *parse_cmd(const char *buf){
+    uint8_t u;
+    if(buf[1] == '\n'){ // one symbol commands
+        if(*buf == '0' || *buf == '1'){
+            BMP280_setup(*buf - '0');
+            if(!BMP280_init()) return "Error in init process\n";
+            return "OK, inited\n";
+        }
+        switch(*buf){
+            case 'I':
+                if(BMP280_read_ID(&u)){
+                    if(u == BMP280_CHIP_ID) return "BMP280\n";
+                    else return "BME280\n";
+                }else return "Failed\n";
+            break;
+            case 'M':
+                if(!BMP280_start()) return "BMP280 not found or not inited\n";
+                else return "Start\n";
+            break;
+            case 'R':
+                USB_send("Soft reset\n");
+                NVIC_SystemReset();
+            break;
+            case 'W':
+                USB_send("Wait for reboot\n");
+                while(1){nop();};
+            break;
+            default:
+                return helpmsg;
+        }
+        return NULL;
+    }
+    uint32_t Num = 0;
+    int32_t I;
+    char *nxt, *bufori = (char*)buf;
+    void (*osfunc)(BMP280_Oversampling);
+    switch(*buf){ // long messages
+        case 'F':
+            ++buf;
+            if(buf != getnum(buf, &Num) && Num < BMP280_FILTERMAX){
+                BMP280_setfilter((BMP280_Filter)Num);
+                return "Changed\n";
+            }else return "Wrong filter number";
+        break;
+        case 'N':
+            ++buf;
+            nxt = getnum(buf, &Num);
+            if(buf == nxt){
+                if(Num == 0) return "Wrong number\n";
+                return "Integer32 overflow\n";
+            }
+            USB_send("ln("); USB_send(u2str(Num)); USB_send(")=");
+            I = ln(Num);
+            USB_send(i2str(I));
+            if(*nxt && *nxt != '\n'){
+                USB_send(", the rest of string: ");
+                USB_send(nxt);
+            }else USB_send("\n");
+        break;
+        case 'O':
+            ++buf;
+            osfunc = NULL;
+            switch(*buf){
+                case 'h': // h_os
+                    osfunc = BMP280_setOSh;
+                break;
+                case 'p': // p_os
+                    osfunc = BMP280_setOSp;
+                break;
+                case 't': // t_os
+                    osfunc = BMP280_setOSt;
+                break;
+                default:
+                    return bufori;
+            }
+            ++buf;
+            if(osfunc && buf != getnum(buf, &Num) && Num < BMP280_OVERSMAX){
+                osfunc((BMP280_Oversampling)Num);
+                return "Changed\n";
+            }else return "Wrong OS number";
+        break;
+        default:
+            return bufori;
+    }
+    return NULL;
+}
+
+static char *_2str(uint32_t  val, uint8_t minus){
+    static char strbuf[12];
+    char *bufptr = &strbuf[11];
+    *bufptr = 0;
+    if(!val){
+        *(--bufptr) = '0';
+    }else{
+        while(val){
+            *(--bufptr) = val % 10 + '0';
+            val /= 10;
+        }
+    }
+    if(minus) *(--bufptr) = '-';
+    return bufptr;
+}
+
+// return string with number `val`
+char *u2str(uint32_t val){
+    return _2str(val, 0);
+}
+char *i2str(int32_t i){
+    uint8_t minus = 0;
+    uint32_t val;
+    if(i < 0){
+        minus = 1;
+        val = -i;
+    }else val = i;
+    return _2str(val, minus);
+}

F1:F103/BMP280/proto.h

@@ -0,0 +1,30 @@
+/*
+ * This file is part of the BMP280 project.
+ * Copyright 2020 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+#ifndef PROTO_H__
+#define PROTO_H__
+
+#include <stm32f1.h>
+
+const char *parse_cmd(const char *buf);
+char *omit_spaces(const char *buf);
+char *getnum(const char *buf, uint32_t *N);
+char *u2str(uint32_t val);
+char *i2str(int32_t val);
+
+#endif // PROTO_H__

F1:F103/BMP280/usb.c

@@ -0,0 +1,167 @@
+/*
+ * This file is part of the BMP280 project.
+ * Copyright 2020 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "usb.h"
+#include "usb_lib.h"
+
+static volatile uint8_t tx_succesfull = 1;
+static volatile uint8_t rxNE = 0;
+
+static int sstrlen(const char *s){
+    if(!s) return 0;
+    int l = 0;
+    while(*s++) ++l;
+    return l;
+}
+
+// interrupt IN handler (never used?)
+static void EP1_Handler(){
+    uint16_t epstatus = KEEP_DTOG(USB->EPnR[1]);
+    if(RX_FLAG(epstatus)) epstatus = (epstatus & ~USB_EPnR_STAT_TX) ^ USB_EPnR_STAT_RX; // set valid RX
+    else epstatus = epstatus & ~(USB_EPnR_STAT_TX|USB_EPnR_STAT_RX);
+    // clear CTR
+    epstatus = (epstatus & ~(USB_EPnR_CTR_RX|USB_EPnR_CTR_TX));
+    USB->EPnR[1] = epstatus;
+}
+
+// data IN/OUT handlers
+static void transmit_Handler(){ // EP3IN
+    tx_succesfull = 1;
+    uint16_t epstatus = KEEP_DTOG_STAT(USB->EPnR[3]);
+    // clear CTR keep DTOGs & STATs
+    USB->EPnR[3] = (epstatus & ~(USB_EPnR_CTR_TX)); // clear TX ctr
+}
+
+static void receive_Handler(){ // EP2OUT
+    rxNE = 1;
+    uint16_t epstatus = KEEP_DTOG_STAT(USB->EPnR[2]);
+    USB->EPnR[2] = (epstatus & ~(USB_EPnR_CTR_RX)); // clear RX ctr
+}
+
+void USB_setup(){
+    NVIC_DisableIRQ(USB_LP_CAN1_RX0_IRQn);
+    NVIC_DisableIRQ(USB_HP_CAN1_TX_IRQn);
+    RCC->APB1ENR |= RCC_APB1ENR_USBEN;
+    USB->CNTR   = USB_CNTR_FRES; // Force USB Reset
+    for(uint32_t ctr = 0; ctr < 72000; ++ctr) nop(); // wait >1ms
+    //uint32_t ctr = 0;
+    USB->CNTR   = 0;
+    USB->BTABLE = 0;
+    USB->DADDR  = 0;
+    USB->ISTR   = 0;
+    USB->CNTR   = USB_CNTR_RESETM | USB_CNTR_WKUPM; // allow only wakeup & reset interrupts
+    NVIC_EnableIRQ(USB_LP_CAN1_RX0_IRQn);
+}
+
+static int usbwr(const char *buf, int l){
+    uint32_t ctra = 1000000;
+    while(--ctra && tx_succesfull == 0){
+        IWDG->KR = IWDG_REFRESH;
+    }
+    tx_succesfull = 0;
+    EP_Write(3, (uint8_t*)buf, l);
+    ctra = 1000000;
+    while(--ctra && tx_succesfull == 0){
+        IWDG->KR = IWDG_REFRESH;
+    }
+    if(tx_succesfull == 0){usbON = 0; return 1;} // usb is OFF?
+    return 0;
+}
+
+static char usbbuff[USB_TXBUFSZ-1]; // temporary buffer (63 - to prevent need of ZLP)
+static int buflen = 0; // amount of symbols in usbbuff
+
+// send next up to 63 bytes of data in usbbuff
+static void send_next(){
+    if(!buflen || !tx_succesfull) return;
+    tx_succesfull = 0;
+    EP_Write(3, (uint8_t*)usbbuff, buflen);
+    buflen = 0;
+}
+
+// unblocking sending - just fill a buffer
+void USB_send(const char *buf){
+    int len = sstrlen(buf);
+    if(!usbON || !len) return;
+    if(len > USB_TXBUFSZ-1 - buflen){
+        usbwr(usbbuff, buflen);
+        buflen = 0;
+    }
+    if(len > USB_TXBUFSZ-1){
+        USB_send_blk(buf, len);
+        return;
+    }
+    while(len--) usbbuff[buflen++] = *buf++;
+}
+
+// blocking sending
+void USB_send_blk(const char *buf, int len){
+    if(!usbON || !len) return; // USB disconnected
+    if(buflen){
+        usbwr(usbbuff, buflen);
+        buflen = 0;
+    }
+    int needzlp = 0;
+    while(len){
+        if(len == USB_TXBUFSZ) needzlp = 1;
+        int s = (len > USB_TXBUFSZ) ? USB_TXBUFSZ : len;
+        if(usbwr(buf, s)) return;
+        len -= s;
+        buf += s;
+    }
+    if(needzlp){
+        usbwr(NULL, 0);
+    }
+}
+
+void usb_proc(){
+    switch(USB_Dev.USB_Status){
+        case USB_STATE_CONFIGURED:
+            // make new BULK endpoint
+            // Buffer have 1024 bytes, but last 256 we use for CAN bus (30.2 of RM: USB main features)
+            EP_Init(1, EP_TYPE_INTERRUPT, USB_EP1BUFSZ, 0, EP1_Handler); // IN1 - transmit
+            EP_Init(2, EP_TYPE_BULK, 0, USB_RXBUFSZ, receive_Handler); // OUT2 - receive data
+            EP_Init(3, EP_TYPE_BULK, USB_TXBUFSZ, 0, transmit_Handler); // IN3 - transmit data
+            USB_Dev.USB_Status = USB_STATE_CONNECTED;
+        break;
+        case USB_STATE_DEFAULT:
+        case USB_STATE_ADDRESSED:
+            if(usbON){
+                usbON = 0;
+            }
+        break;
+        default: // USB_STATE_CONNECTED - send next data portion
+            if(!usbON) return;
+            send_next();
+    }
+}
+
+/**
+ * @brief USB_receive
+ * @param buf (i) - buffer[64] for received data
+ * @return amount of received bytes
+ */
+int USB_receive(char *buf){
+    if(!usbON || !rxNE) return 0;
+    int sz = EP_Read(2, (uint16_t*)buf);
+    uint16_t epstatus = KEEP_DTOG(USB->EPnR[2]);
+    // keep stat_tx & set ACK rx
+    USB->EPnR[2] = (epstatus & ~(USB_EPnR_STAT_TX)) ^ USB_EPnR_STAT_RX;
+    rxNE = 0;
+    return sz;
+}

F1:F103/BMP280/usb.h

@@ -0,0 +1,33 @@
+/*
+ * This file is part of the BMP280 project.
+ * Copyright 2020 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#ifndef __USB_H__
+#define __USB_H__
+
+#include "hardware.h"
+
+#define BUFFSIZE   (64)
+
+void USB_setup();
+void usb_proc();
+void USB_send(const char *buf);
+void USB_send_blk(const char *buf, int len);
+int USB_receive(char *buf);
+
+#endif // __USB_H__

F1:F103/BMP280/usb_defs.h

@@ -0,0 +1,102 @@
+/*
+ * This file is part of the BMP280 project.
+ * Copyright 2020 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#ifndef __USB_DEFS_H__
+#define __USB_DEFS_H__
+
+#include <stm32f1.h>
+
+// max endpoints number
+#define STM32ENDPOINTS          8
+/**
+ *                 Buffers size definition
+ **/
+#define USB_BTABLE_SIZE         512
+// first 64 bytes of USB_BTABLE are registers!
+//#define USB_EP0_BASEADDR        64
+// for USB FS EP0 buffers are from 8 to 64 bytes long (64 for PL2303)
+#define USB_EP0_BUFSZ           64
+// USB transmit buffer size (64 for PL2303)
+#define USB_TXBUFSZ             64
+// USB receive buffer size (64 for PL2303)
+#define USB_RXBUFSZ             64
+// EP1 - interrupt - buffer size
+#define USB_EP1BUFSZ            8
+
+#define USB_BTABLE_BASE         0x40006000
+#define USB_BASE                ((uint32_t)0x40005C00)
+#define USB                     ((USB_TypeDef *) USB_BASE)
+
+#ifdef USB_BTABLE
+#undef USB_BTABLE
+#endif
+#define USB_BTABLE              ((USB_BtableDef *)(USB_BTABLE_BASE))
+#define USB_ISTR_EPID           0x0000000F
+#define USB_FNR_LSOF_0          0x00000800
+#define USB_FNR_lSOF_1          0x00001000
+#define USB_LPMCSR_BESL_0       0x00000010
+#define USB_LPMCSR_BESL_1       0x00000020
+#define USB_LPMCSR_BESL_2       0x00000040
+#define USB_LPMCSR_BESL_3       0x00000080
+#define USB_EPnR_CTR_RX         0x00008000
+#define USB_EPnR_DTOG_RX        0x00004000
+#define USB_EPnR_STAT_RX        0x00003000
+#define USB_EPnR_STAT_RX_0      0x00001000
+#define USB_EPnR_STAT_RX_1      0x00002000
+#define USB_EPnR_SETUP          0x00000800
+#define USB_EPnR_EP_TYPE        0x00000600
+#define USB_EPnR_EP_TYPE_0      0x00000200
+#define USB_EPnR_EP_TYPE_1      0x00000400
+#define USB_EPnR_EP_KIND        0x00000100
+#define USB_EPnR_CTR_TX         0x00000080
+#define USB_EPnR_DTOG_TX        0x00000040
+#define USB_EPnR_STAT_TX        0x00000030
+#define USB_EPnR_STAT_TX_0      0x00000010
+#define USB_EPnR_STAT_TX_1      0x00000020
+#define USB_EPnR_EA             0x0000000F
+#define USB_COUNTn_RX_BLSIZE    0x00008000
+#define USB_COUNTn_NUM_BLOCK    0x00007C00
+#define USB_COUNTn_RX           0x0000003F
+
+#ifdef USB_TypeDef
+#define USB_TypeDef USB_TypeDef_custom
+#endif
+
+typedef struct {
+    __IO uint32_t EPnR[STM32ENDPOINTS];
+    __IO uint32_t RESERVED[STM32ENDPOINTS];
+    __IO uint32_t CNTR;
+    __IO uint32_t ISTR;
+    __IO uint32_t FNR;
+    __IO uint32_t DADDR;
+    __IO uint32_t BTABLE;
+} USB_TypeDef;
+
+typedef struct{
+    __IO uint32_t USB_ADDR_TX;
+    __IO uint32_t USB_COUNT_TX;
+    __IO uint32_t USB_ADDR_RX;
+    __IO uint32_t USB_COUNT_RX;
+} USB_EPDATA_TypeDef;
+
+typedef struct{
+    __IO USB_EPDATA_TypeDef EP[STM32ENDPOINTS];
+} USB_BtableDef;
+
+#endif // __USB_DEFS_H__

F1:F103/BMP280/usb_lib.c

@@ -0,0 +1,476 @@
+/*
+ * This file is part of the BMP280 project.
+ * Copyright 2020 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdint.h>
+#include "usb_lib.h"
+
+ep_t endpoints[STM32ENDPOINTS];
+
+usb_dev_t USB_Dev;
+static usb_LineCoding lineCoding = {115200, 0, 0, 8};
+static config_pack_t setup_packet;
+static uint8_t ep0databuf[EP0DATABUF_SIZE];
+static uint8_t ep0dbuflen = 0;
+
+usb_LineCoding getLineCoding(){return lineCoding;}
+
+uint8_t usbON = 0; // device disconnected from terminal
+
+// definition of parts common for USB_DeviceDescriptor & USB_DeviceQualifierDescriptor
+#define bcdUSB_L        0x10
+#define bcdUSB_H        0x01
+#define bDeviceClass    0
+#define bDeviceSubClass 0
+#define bDeviceProtocol 0
+#define bNumConfigurations 1
+
+static const uint8_t USB_DeviceDescriptor[] = {
+        18,     // bLength
+        0x01,   // bDescriptorType - Device descriptor
+        bcdUSB_L,   // bcdUSB_L - 1.10
+        bcdUSB_H,   // bcdUSB_H
+        bDeviceClass,   // bDeviceClass - USB_COMM
+        bDeviceSubClass,   // bDeviceSubClass
+        bDeviceProtocol,   // bDeviceProtocol
+        USB_EP0_BUFSZ,   // bMaxPacketSize
+        0x7b,   // idVendor_L PL2303: VID=0x067b, PID=0x2303
+        0x06,   // idVendor_H
+        0x03,   // idProduct_L
+        0x23,   // idProduct_H
+        0x00,   // bcdDevice_Ver_L
+        0x03,   // bcdDevice_Ver_H
+        0x01,   // iManufacturer
+        0x02,   // iProduct
+        0x00,   // iSerialNumber
+        bNumConfigurations    // bNumConfigurations
+};
+
+static const uint8_t USB_DeviceQualifierDescriptor[] = {
+        10,     //bLength
+        0x06,   // bDescriptorType - Device qualifier
+        bcdUSB_L,   // bcdUSB_L
+        bcdUSB_H,   // bcdUSB_H
+        bDeviceClass,   // bDeviceClass
+        bDeviceSubClass,   // bDeviceSubClass
+        bDeviceProtocol,   // bDeviceProtocol
+        USB_EP0_BUFSZ,   // bMaxPacketSize0
+        bNumConfigurations,   // bNumConfigurations
+        0x00    // Reserved
+};
+
+static const uint8_t USB_ConfigDescriptor[] = {
+        /*Configuration Descriptor*/
+        0x09, /* bLength: Configuration Descriptor size */
+        0x02, /* bDescriptorType: Configuration */
+        39,   /* wTotalLength:no of returned bytes */
+        0x00,
+        0x01, /* bNumInterfaces: 1 interface */
+        0x01, /* bConfigurationValue: Configuration value */
+        0x00, /* iConfiguration: Index of string descriptor describing the configuration */
+        0xa0, /* bmAttributes - Bus powered, Remote wakeup */
+        0x32, /* MaxPower 100 mA */
+
+        /*---------------------------------------------------------------------------*/
+
+        /*Interface Descriptor */
+        0x09, /* bLength: Interface Descriptor size */
+        0x04, /* bDescriptorType: Interface */
+        0x00, /* bInterfaceNumber: Number of Interface */
+        0x00, /* bAlternateSetting: Alternate setting */
+        0x03, /* bNumEndpoints: 3 endpoints used */
+        0xff, /* bInterfaceClass */
+        0x00, /* bInterfaceSubClass */
+        0x00, /* bInterfaceProtocol */
+        0x00, /* iInterface: */
+///////////////////////////////////////////////////
+        /*Endpoint 1 Descriptor*/
+        0x07, /* bLength: Endpoint Descriptor size */
+        0x05, /* bDescriptorType: Endpoint */
+        0x81, /* bEndpointAddress IN1 */
+        0x03, /* bmAttributes: Interrupt */
+        0x0a, /* wMaxPacketSize LO: */
+        0x00, /* wMaxPacketSize HI: */
+        0x01, /* bInterval: */
+
+        /*Endpoint OUT2 Descriptor*/
+        0x07, /* bLength: Endpoint Descriptor size */
+        0x05, /* bDescriptorType: Endpoint */
+        0x02, /* bEndpointAddress: OUT2 */
+        0x02, /* bmAttributes: Bulk */
+        (USB_RXBUFSZ & 0xff), /* wMaxPacketSize: 64 */
+        (USB_RXBUFSZ >> 8),
+        0x00, /* bInterval: ignore for Bulk transfer */
+
+        /*Endpoint IN3 Descriptor*/
+        0x07, /* bLength: Endpoint Descriptor size */
+        0x05, /* bDescriptorType: Endpoint */
+        0x83, /* bEndpointAddress IN3 */
+        0x02, /* bmAttributes: Bulk */
+        (USB_TXBUFSZ & 0xff), /* wMaxPacketSize: 64 */
+        (USB_TXBUFSZ >> 8),
+        0x00, /* bInterval: ignore for Bulk transfer */
+};
+
+_USB_LANG_ID_(USB_StringLangDescriptor, LANG_US);
+// these descriptors are not used in PL2303 emulator!
+_USB_STRING_(USB_StringSerialDescriptor, u"0");
+_USB_STRING_(USB_StringManufacturingDescriptor, u"Prolific Technology Inc.");
+_USB_STRING_(USB_StringProdDescriptor, u"USB-Serial Controller");
+
+/*
+ * default handlers
+ */
+// SET_LINE_CODING
+void WEAK linecoding_handler(usb_LineCoding __attribute__((unused)) *lc){
+}
+
+// SET_CONTROL_LINE_STATE
+void WEAK clstate_handler(uint16_t __attribute__((unused)) val){
+}
+
+// SEND_BREAK
+void WEAK break_handler(){
+}
+
+// handler of vendor requests
+void WEAK vendor_handler(config_pack_t *packet){
+    if(packet->bmRequestType & 0x80){ // read
+        uint8_t c;
+        switch(packet->wValue){
+            case 0x8484:
+                c = 2;
+            break;
+            case 0x0080:
+                c = 1;
+            break;
+            case 0x8686:
+                c = 0xaa;
+            break;
+            default:
+                c = 0;
+        }
+        EP_WriteIRQ(0, &c, 1);
+    }else{ // write ZLP
+        EP_WriteIRQ(0, (uint8_t *)0, 0);
+    }
+}
+
+static void wr0(const uint8_t *buf, uint16_t size){
+    if(setup_packet.wLength < size) size = setup_packet.wLength; // shortened request
+    if(size < endpoints[0].txbufsz){
+        EP_WriteIRQ(0, buf, size);
+        return;
+    }
+    while(size){
+        uint16_t l = size;
+        if(l > endpoints[0].txbufsz) l = endpoints[0].txbufsz;
+        EP_WriteIRQ(0, buf, l);
+        buf += l;
+        size -= l;
+        uint8_t needzlp = (l == endpoints[0].txbufsz) ? 1 : 0;
+        if(size || needzlp){ // send last data buffer
+            uint16_t status = KEEP_DTOG(USB->EPnR[0]);
+            // keep DTOGs, clear CTR_RX,TX, set TX VALID, leave stat_Rx
+            USB->EPnR[0] = (status & ~(USB_EPnR_CTR_RX|USB_EPnR_CTR_TX|USB_EPnR_STAT_RX))
+                            ^ USB_EPnR_STAT_TX;
+            uint32_t ctr = 1000000;
+            while(--ctr && (USB->ISTR & USB_ISTR_CTR) == 0){IWDG->KR = IWDG_REFRESH;};
+            if((USB->ISTR & USB_ISTR_CTR) == 0){
+                return;
+            }
+            if(needzlp) EP_WriteIRQ(0, (uint8_t*)0, 0);
+        }
+    }
+}
+
+static inline void get_descriptor(){
+    switch(setup_packet.wValue){
+        case DEVICE_DESCRIPTOR:
+            wr0(USB_DeviceDescriptor, sizeof(USB_DeviceDescriptor));
+        break;
+        case CONFIGURATION_DESCRIPTOR:
+            wr0(USB_ConfigDescriptor, sizeof(USB_ConfigDescriptor));
+        break;
+        case STRING_LANG_DESCRIPTOR:
+            wr0((const uint8_t *)&USB_StringLangDescriptor, STRING_LANG_DESCRIPTOR_SIZE_BYTE);
+        break;
+        case STRING_MAN_DESCRIPTOR:
+            wr0((const uint8_t *)&USB_StringManufacturingDescriptor, USB_StringManufacturingDescriptor.bLength);
+        break;
+        case STRING_PROD_DESCRIPTOR:
+            wr0((const uint8_t *)&USB_StringProdDescriptor, USB_StringProdDescriptor.bLength);
+        break;
+        case STRING_SN_DESCRIPTOR:
+            wr0((const uint8_t *)&USB_StringSerialDescriptor, USB_StringSerialDescriptor.bLength);
+        break;
+        case DEVICE_QUALIFIER_DESCRIPTOR:
+            wr0(USB_DeviceQualifierDescriptor, USB_DeviceQualifierDescriptor[0]);
+        break;
+        default:
+        break;
+    }
+}
+
+static uint8_t configuration = 0; // reply for GET_CONFIGURATION (==1 if configured)
+static inline void std_d2h_req(){
+    uint16_t status = 0; // bus powered
+    switch(setup_packet.bRequest){
+        case GET_DESCRIPTOR:
+            get_descriptor();
+        break;
+        case GET_STATUS:
+            EP_WriteIRQ(0, (uint8_t *)&status, 2); // send status: Bus Powered
+        break;
+        case GET_CONFIGURATION:
+            EP_WriteIRQ(0, &configuration, 1);
+        break;
+        default:
+        break;
+    }
+}
+
+static inline void std_h2d_req(){
+    switch(setup_packet.bRequest){
+        case SET_ADDRESS:
+            // new address will be assigned later - after  acknowlegement or request to host
+            USB_Dev.USB_Addr = setup_packet.wValue;
+        break;
+        case SET_CONFIGURATION:
+            // Now device configured
+            USB_Dev.USB_Status = USB_STATE_CONFIGURED;
+            configuration = setup_packet.wValue;
+        break;
+        default:
+        break;
+    }
+}
+
+/*
+bmRequestType: 76543210
+7    direction: 0 - host->device, 1 - device->host
+65   type: 0 - standard, 1 - class, 2 - vendor
+4..0 getter: 0 - device, 1 - interface, 2 - endpoint, 3 - other
+*/
+/**
+ * Endpoint0 (control) handler
+ */
+static void EP0_Handler(){
+    uint16_t epstatus = USB->EPnR[0]; // EP0R on input -> return this value after modifications
+    uint8_t reqtype = setup_packet.bmRequestType & 0x7f;
+    uint8_t dev2host = (setup_packet.bmRequestType & 0x80) ? 1 : 0;
+    int rxflag = RX_FLAG(epstatus);
+    if(rxflag && SETUP_FLAG(epstatus)){
+        switch(reqtype){
+            case STANDARD_DEVICE_REQUEST_TYPE: // standard device request
+                if(dev2host){
+                    std_d2h_req();
+                }else{
+                    std_h2d_req();
+                    EP_WriteIRQ(0, (uint8_t *)0, 0);
+                }
+            break;
+            case STANDARD_ENDPOINT_REQUEST_TYPE: // standard endpoint request
+                if(setup_packet.bRequest == CLEAR_FEATURE){
+                    EP_WriteIRQ(0, (uint8_t *)0, 0);
+                }
+            break;
+            case VENDOR_REQUEST_TYPE:
+                vendor_handler(&setup_packet);
+            break;
+            case CONTROL_REQUEST_TYPE:
+                switch(setup_packet.bRequest){
+                    case GET_LINE_CODING:
+                        EP_WriteIRQ(0, (uint8_t*)&lineCoding, sizeof(lineCoding));
+                    break;
+                    case SET_LINE_CODING: // omit this for next stage, when data will come
+                    break;
+                    case SET_CONTROL_LINE_STATE:
+                        usbON = 1;
+                        clstate_handler(setup_packet.wValue);
+                    break;
+                    case SEND_BREAK:
+                        usbON = 0;
+                        break_handler();
+                    break;
+                    default:
+                    break;
+                }
+                if(setup_packet.bRequest != GET_LINE_CODING) EP_WriteIRQ(0, (uint8_t *)0, 0); // write acknowledgement
+            break;
+            default:
+                EP_WriteIRQ(0, (uint8_t *)0, 0);
+        }
+    }else if(rxflag){ // got data over EP0 or host acknowlegement
+        if(endpoints[0].rx_cnt){
+            if(setup_packet.bRequest == SET_LINE_CODING){
+                linecoding_handler((usb_LineCoding*)ep0databuf);
+            }
+        }
+    } else if(TX_FLAG(epstatus)){ // package transmitted
+        // now we can change address after enumeration
+        if ((USB->DADDR & USB_DADDR_ADD) != USB_Dev.USB_Addr){
+            USB->DADDR = USB_DADDR_EF | USB_Dev.USB_Addr;
+            // change state to ADRESSED
+            USB_Dev.USB_Status = USB_STATE_ADDRESSED;
+        }
+    }
+    epstatus = KEEP_DTOG(USB->EPnR[0]);
+    if(rxflag) epstatus ^= USB_EPnR_STAT_TX; // start ZLP/data transmission
+    else epstatus &= ~USB_EPnR_STAT_TX; // or leave unchanged
+    // keep DTOGs, clear CTR_RX,TX, set RX VALID
+    USB->EPnR[0] = (epstatus & ~(USB_EPnR_CTR_RX|USB_EPnR_CTR_TX)) ^ USB_EPnR_STAT_RX;
+}
+
+static uint16_t lastaddr = LASTADDR_DEFAULT;
+/**
+ * Endpoint initialisation
+ * @param number - EP num (0...7)
+ * @param type - EP type (EP_TYPE_BULK, EP_TYPE_CONTROL, EP_TYPE_ISO, EP_TYPE_INTERRUPT)
+ * @param txsz - transmission buffer size @ USB/CAN buffer
+ * @param rxsz - reception buffer size @ USB/CAN buffer
+ * @param uint16_t (*func)(ep_t *ep) - EP handler function
+ * @return 0 if all OK
+ */
+int EP_Init(uint8_t number, uint8_t type, uint16_t txsz, uint16_t rxsz, void (*func)(ep_t ep)){
+    if(number >= STM32ENDPOINTS) return 4; // out of configured amount
+    if(txsz > USB_BTABLE_SIZE || rxsz > USB_BTABLE_SIZE) return 1; // buffer too large
+    if(lastaddr + txsz + rxsz >= USB_BTABLE_SIZE) return 2; // out of btable
+    USB->EPnR[number] = (type << 9) | (number & USB_EPnR_EA);
+    USB->EPnR[number] ^= USB_EPnR_STAT_RX | USB_EPnR_STAT_TX_1;
+    if(rxsz & 1 || rxsz > 512) return 3; // wrong rx buffer size
+    uint16_t countrx = 0;
+    if(rxsz < 64) countrx = rxsz / 2;
+    else{
+        if(rxsz & 0x1f) return 3; // should be multiple of 32
+        countrx = 31 + rxsz / 32;
+    }
+    USB_BTABLE->EP[number].USB_ADDR_TX = lastaddr;
+    endpoints[number].tx_buf = (uint16_t *)(USB_BTABLE_BASE + lastaddr*2);
+    endpoints[number].txbufsz = txsz;
+    lastaddr += txsz;
+    USB_BTABLE->EP[number].USB_COUNT_TX = 0;
+    USB_BTABLE->EP[number].USB_ADDR_RX = lastaddr;
+    endpoints[number].rx_buf = (uint16_t *)(USB_BTABLE_BASE + lastaddr*2);
+    lastaddr += rxsz;
+    USB_BTABLE->EP[number].USB_COUNT_RX = countrx << 10;
+    endpoints[number].func = func;
+    return 0;
+}
+
+// standard IRQ handler
+void usb_lp_can_rx0_isr(){
+    if(USB->ISTR & USB_ISTR_RESET){
+        usbON = 0;
+        // Reinit registers
+        USB->CNTR = USB_CNTR_RESETM | USB_CNTR_CTRM | USB_CNTR_SUSPM | USB_CNTR_WKUPM;
+        USB->ISTR = 0;
+        // Endpoint 0 - CONTROL
+        // ON USB LS size of EP0 may be 8 bytes, but on FS it should be 64 bytes!
+        lastaddr = LASTADDR_DEFAULT;
+        // clear address, leave only enable bit
+        USB->DADDR = USB_DADDR_EF;
+        USB_Dev.USB_Status = USB_STATE_DEFAULT;
+        USB->ISTR = ~USB_ISTR_RESET;
+        if(EP_Init(0, EP_TYPE_CONTROL, USB_EP0_BUFSZ, USB_EP0_BUFSZ, EP0_Handler)){
+            return;
+        }
+    }
+    if(USB->ISTR & USB_ISTR_CTR){
+        // EP number
+        uint8_t n = USB->ISTR & USB_ISTR_EPID;
+        // copy status register
+        uint16_t epstatus = USB->EPnR[n];
+        // copy received bytes amount
+        endpoints[n].rx_cnt = USB_BTABLE->EP[n].USB_COUNT_RX & 0x3FF; // low 10 bits is counter
+        // check direction
+        if(USB->ISTR & USB_ISTR_DIR){ // OUT interrupt - receive data, CTR_RX==1 (if CTR_TX == 1 - two pending transactions: receive following by transmit)
+            if(n == 0){ // control endpoint
+                if(epstatus & USB_EPnR_SETUP){ // setup packet -> copy data to conf_pack
+                    EP_Read(0, (uint16_t*)&setup_packet);
+                    ep0dbuflen = 0;
+                    // interrupt handler will be called later
+                }else if(epstatus & USB_EPnR_CTR_RX){ // data packet -> push received data to ep0databuf
+                    ep0dbuflen = endpoints[0].rx_cnt;
+                    EP_Read(0, (uint16_t*)&ep0databuf);
+                }
+            }
+        }
+        // call EP handler
+        if(endpoints[n].func) endpoints[n].func(endpoints[n]);
+    }
+    if(USB->ISTR & USB_ISTR_SUSP){ // suspend -> still no connection, may sleep
+        usbON = 0;
+        USB->CNTR |= USB_CNTR_FSUSP | USB_CNTR_LP_MODE;
+        USB->ISTR = ~USB_ISTR_SUSP;
+    }
+    if(USB->ISTR & USB_ISTR_WKUP){ // wakeup
+        USB->CNTR &= ~(USB_CNTR_FSUSP | USB_CNTR_LP_MODE); // clear suspend flags
+        USB->ISTR = ~USB_ISTR_WKUP;
+    }
+}
+
+/**
+ * Write data to EP buffer (called from IRQ handler)
+ * @param number - EP number
+ * @param *buf - array with data
+ * @param size - its size
+ */
+void EP_WriteIRQ(uint8_t number, const uint8_t *buf, uint16_t size){
+    uint8_t i;
+    if(size > endpoints[number].txbufsz) size = endpoints[number].txbufsz;
+    uint16_t N2 = (size + 1) >> 1;
+    // the buffer is 16-bit, so we should copy data as it would be uint16_t
+    uint16_t *buf16 = (uint16_t *)buf;
+    uint32_t *out = (uint32_t *)endpoints[number].tx_buf;
+    for(i = 0; i < N2; ++i, ++out){
+        *out = buf16[i];
+    }
+    USB_BTABLE->EP[number].USB_COUNT_TX = size;
+}
+
+/**
+ * Write data to EP buffer (called outside IRQ handler)
+ * @param number - EP number
+ * @param *buf - array with data
+ * @param size - its size
+ */
+void EP_Write(uint8_t number, const uint8_t *buf, uint16_t size){
+    EP_WriteIRQ(number, buf, size);
+    uint16_t status = KEEP_DTOG(USB->EPnR[number]);
+    // keep DTOGs, clear CTR_TX & set TX VALID to start transmission
+    USB->EPnR[number] = (status & ~(USB_EPnR_CTR_TX)) ^ USB_EPnR_STAT_TX;
+}
+
+/*
+ * Copy data from EP buffer into user buffer area
+ * @param *buf - user array for data
+ * @return amount of data read
+ */
+int EP_Read(uint8_t number, uint16_t *buf){
+    int sz = endpoints[number].rx_cnt;
+    if(!sz) return 0;
+    endpoints[number].rx_cnt = 0;
+    int n = (sz + 1) >> 1;
+    uint32_t *in = (uint32_t *)endpoints[number].rx_buf;
+    if(n){
+        for(int i = 0; i < n; ++i, ++in)
+            buf[i] = *(uint16_t*)in;
+    }
+    return sz;
+}
+

F1:F103/BMP280/usb_lib.h

@@ -0,0 +1,184 @@
+/*
+ * This file is part of the BMP280 project.
+ * Copyright 2020 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#ifndef __USB_LIB_H__
+#define __USB_LIB_H__
+
+#include <wchar.h>
+#include "usb_defs.h"
+
+#define EP0DATABUF_SIZE                 (64)
+#define LASTADDR_DEFAULT                (STM32ENDPOINTS * 8)
+
+// bmRequestType & 0x7f
+#define STANDARD_DEVICE_REQUEST_TYPE    0
+#define STANDARD_ENDPOINT_REQUEST_TYPE  2
+#define VENDOR_REQUEST_TYPE             0x40
+#define CONTROL_REQUEST_TYPE            0x21
+// bRequest, standard; for bmRequestType == 0x80
+#define GET_STATUS                      0x00
+#define GET_DESCRIPTOR                  0x06
+#define GET_CONFIGURATION               0x08
+// for bmRequestType == 0
+#define CLEAR_FEATURE                   0x01
+#define SET_FEATURE                     0x03    // unused
+#define SET_ADDRESS                     0x05
+#define SET_DESCRIPTOR                  0x07    // unused
+#define SET_CONFIGURATION               0x09
+// for bmRequestType == 0x81, 1 or 0xB2
+#define GET_INTERFACE                   0x0A    // unused
+#define SET_INTERFACE                   0x0B    // unused
+#define SYNC_FRAME                      0x0C    // unused
+#define VENDOR_REQUEST                  0x01    // unused
+
+// Class-Specific Control Requests
+#define SEND_ENCAPSULATED_COMMAND       0x00    // unused
+#define GET_ENCAPSULATED_RESPONSE       0x01    // unused
+#define SET_COMM_FEATURE                0x02    // unused
+#define GET_COMM_FEATURE                0x03    // unused
+#define CLEAR_COMM_FEATURE              0x04    // unused
+#define SET_LINE_CODING                 0x20
+#define GET_LINE_CODING                 0x21
+#define SET_CONTROL_LINE_STATE          0x22
+#define SEND_BREAK                      0x23
+
+// control line states
+#define CONTROL_DTR                     0x01
+#define CONTROL_RTS                     0x02
+
+// wValue
+#define DEVICE_DESCRIPTOR               0x100
+#define CONFIGURATION_DESCRIPTOR        0x200
+#define STRING_LANG_DESCRIPTOR          0x300
+#define STRING_MAN_DESCRIPTOR           0x301
+#define STRING_PROD_DESCRIPTOR          0x302
+#define STRING_SN_DESCRIPTOR            0x303
+#define DEVICE_QUALIFIER_DESCRIPTOR     0x600
+
+#define RX_FLAG(epstat)                 (epstat & USB_EPnR_CTR_RX)
+#define TX_FLAG(epstat)                 (epstat & USB_EPnR_CTR_TX)
+#define SETUP_FLAG(epstat)              (epstat & USB_EPnR_SETUP)
+
+// EPnR bits manipulation
+#define KEEP_DTOG_STAT(EPnR)            (EPnR & ~(USB_EPnR_STAT_RX|USB_EPnR_STAT_TX|USB_EPnR_DTOG_RX|USB_EPnR_DTOG_TX))
+#define KEEP_DTOG(EPnR)                 (EPnR & ~(USB_EPnR_DTOG_RX|USB_EPnR_DTOG_TX))
+
+// USB state: uninitialized, addressed, ready for use
+typedef enum{
+    USB_STATE_DEFAULT,
+    USB_STATE_ADDRESSED,
+    USB_STATE_CONFIGURED,
+    USB_STATE_CONNECTED
+} USB_state;
+
+// EP types
+#define EP_TYPE_BULK                    0x00
+#define EP_TYPE_CONTROL                 0x01
+#define EP_TYPE_ISO                     0x02
+#define EP_TYPE_INTERRUPT               0x03
+
+#define LANG_US (uint16_t)0x0409
+
+#define _USB_STRING_(name, str)                  \
+static const struct name \
+{                          \
+        uint8_t  bLength;                       \
+        uint8_t  bDescriptorType;               \
+        uint16_t bString[(sizeof(str) - 2) / 2]; \
+    \
+} \
+name = {sizeof(name), 0x03, str}
+
+#define _USB_LANG_ID_(name, lng_id)     \
+    \
+static const struct name \
+{         \
+        uint8_t  bLength;         \
+        uint8_t  bDescriptorType; \
+        uint16_t bString;         \
+    \
+} \
+name = {0x04, 0x03, lng_id}
+#define STRING_LANG_DESCRIPTOR_SIZE_BYTE    (4)
+
+// EP0 configuration packet
+typedef struct {
+    uint8_t bmRequestType;
+    uint8_t bRequest;
+    uint16_t wValue;
+    uint16_t wIndex;
+    uint16_t wLength;
+} config_pack_t;
+
+// endpoints state
+typedef struct{
+    uint16_t *tx_buf;           // transmission buffer address
+    uint16_t txbufsz;           // transmission buffer size
+    uint16_t *rx_buf;           // reception buffer address
+    void (*func)();             // endpoint action function
+    unsigned rx_cnt  : 10;      // received data counter
+} ep_t;
+
+// USB status & its address
+typedef struct {
+    uint8_t  USB_Status;
+    uint16_t USB_Addr;
+}usb_dev_t;
+
+typedef struct {
+    uint32_t dwDTERate;
+    uint8_t bCharFormat;
+    #define USB_CDC_1_STOP_BITS   0
+    #define USB_CDC_1_5_STOP_BITS 1
+    #define USB_CDC_2_STOP_BITS   2
+    uint8_t bParityType;
+    #define USB_CDC_NO_PARITY     0
+    #define USB_CDC_ODD_PARITY    1
+    #define USB_CDC_EVEN_PARITY   2
+    #define USB_CDC_MARK_PARITY   3
+    #define USB_CDC_SPACE_PARITY  4
+    uint8_t bDataBits;
+} __attribute__ ((packed)) usb_LineCoding;
+
+typedef struct {
+    uint8_t   bmRequestType;
+    uint8_t   bNotificationType;
+    uint16_t  wValue;
+    uint16_t  wIndex;
+    uint16_t  wLength;
+} __attribute__ ((packed)) usb_cdc_notification;
+
+extern ep_t endpoints[];
+extern usb_dev_t USB_Dev;
+extern uint8_t usbON;
+
+void USB_Init();
+void USB_ResetState();
+int EP_Init(uint8_t number, uint8_t type, uint16_t txsz, uint16_t rxsz, void (*func)());
+void EP_WriteIRQ(uint8_t number, const uint8_t *buf, uint16_t size);
+void EP_Write(uint8_t number, const uint8_t *buf, uint16_t size);
+int EP_Read(uint8_t number, uint16_t *buf);
+usb_LineCoding getLineCoding();
+
+void linecoding_handler(usb_LineCoding *lc);
+void clstate_handler(uint16_t val);
+void break_handler();
+void vendor_handler(config_pack_t *packet);
+
+#endif // __USB_LIB_H__

F1:F103/BUGS

@@ -0,0 +1,49 @@
+ 1. Непонимание что такое "атомарный доступ" и для чего нужно "volatile" при совместной работе разных процессов/ISR с одними данными.
+
+Смотрим например на usart2_getline() вызывающуюся в фоне и usart2_isr() (видимо - ISR), и думаем что будет если прерывание usart2_isr() произойдёт между строкой
+
+int L = linerdy;
+
+и строкой
+
+linerdy = 0;
+
+ 
+
+2. Алгоритм работы с приёмным потоком UART - в корне ущербный. Достаточно подумать, что будет если на большой скорости UART два символа '\n' подряд и в это время фоновая задача будет занята какой-то более-менее длительной работой (а ведь мы знаем что автор сего - ненавистник РТОС, и у него не будет повышен приоритет задаче, разгребающей UART-RX поток ;).
+
+ 
+
+3. Инициализация UART (usart2_setup()) - кривая. Сначала автор программирует DMA на работу с UART, включает его, и только затем включает тактирование UART и инициализирует его.
+
+Также - мультиплексор пинов переключает ноги с GPIO на UART ещё до инициализации самого UART (глитчи обеспечены).
+
+Правильный порядок: 1) инит DMA; 2) инит UART; 3) разрешение DMA; 4) разрешение прерываний; 5) переключение мультиплексора ног GPIO->UART. И не забывать использовать __DMB() где надо.
+
+ 
+
+4. Зачем в main() такое?:
+
+const char dummy[] = "dummy text\n", err[] = "Error!\n";
+
+Видимо чтобы получить как можно более тяжёлый код и занять побольше стека. Автор видимо не знает для чего нужно "static".  :unknw:
+
+ 
+
+5. Автор не читает мануал на используемый МК. Если бы читал, не писал бы такое:
+
+USART2_ICR |= USART_ISR_CMF; // clear flag
+
+Читаем описание регистра USART2_ICR и думаем: Что будет с остальными флагами кроме CMF после такой операции? Да и вообще - зачем читать из регистра если для сброса флага нужна запись в него "1"??? Тема эта уже 100500 раз обсасывалась здесь на форуме.
+
+То же самое здесь:
+
+DMA1_IFCR |= DMA_IFCR_CIF4; // clear TC flag
+
+и в других подобных местах. Регистр DMA1_IFCR - write-only! Опять же - RTFM.
+
+Наверняка ещё куча подобных багов есть - смотрел по диагонали.
+
+ 
+
+6. Исходник просто наполнен "магическими" числами - стиль программирования начинающего. Плохой стиль. 

F1:F103/CDC_ACM/Makefile

@@ -0,0 +1,159 @@
+# make debug adds -DEBUG -Werror
+# make ADDEFS="additional defs"
+BINARY		= cdcacm
+BOOTPORT	?= /dev/ttyUSB0
+BOOTSPEED	?= 115200
+# MCU FAMILY
+FAMILY		?= F1
+# MCU code
+MCU			?= F103x8
+# density (stm32f10x.h, lines 70-84)
+DENSITY 	?= MD
+# change this linking script depending on particular MCU model,
+LDSCRIPT	?= stm32f103x8.ld
+DEFS		= ${ADDEFS} -DVERSION=\"0.0.1\"
+TARGET := RELEASE
+# proxy GPS output over USART1
+#DEFS += -DUSART1PROXY
+
+FP_FLAGS	?= -msoft-float -mfloat-abi=soft
+ASM_FLAGS	?= -mthumb -mcpu=cortex-m3 -mfix-cortex-m3-ldrd
+ARCH_FLAGS	= $(ASM_FLAGS) $(FP_FLAGS)
+
+###############################################################################
+# Executables
+#PREFIX		?= arm-none-eabi
+# gcc from arm web site 
+PREFIX		?= /opt/bin/arm-none-eabi
+TOOLCHLIB	?= /opt/arm-none-eabi/lib
+RM			:= rm -f
+RMDIR		:= rmdir
+CC			:= $(PREFIX)-gcc
+# don't replace ld with gcc: the binary size would be much greater!!
+LD			:= $(PREFIX)-ld
+AR			:= $(PREFIX)-ar
+AS			:= $(PREFIX)-as
+SIZE 		:= $(PREFIX)-size
+OBJCOPY		:= $(PREFIX)-objcopy
+OBJDUMP		:= $(PREFIX)-objdump
+GDB			:= $(PREFIX)-gdb
+STFLASH		:= $(shell which st-flash)
+STBOOT		:= $(shell which stm32flash)
+DFUUTIL		:= $(shell which dfu-util)
+
+###############################################################################
+# Source files
+OBJDIR 		= mk
+SRC			:= $(wildcard *.c)
+OBJS		:= $(addprefix $(OBJDIR)/, $(SRC:%.c=%.o))
+STARTUP		= $(OBJDIR)/startup.o
+OBJS 		+= $(STARTUP)
+# dependencies: we need them to recompile files if their headers-dependencies changed
+DEPS		:= $(OBJS:.o=.d)
+
+INC_DIR ?= ../inc
+
+INCLUDE 	:= -I$(INC_DIR)/Fx -I$(INC_DIR)/cm
+LIB_DIR		:= $(INC_DIR)/ld
+
+###############################################################################
+# C flags
+CFLAGS		+= -O2 -g -D__thumb2__=1 -MD
+CFLAGS		+= -Wall -Wextra -Wshadow 
+CFLAGS		+= -fno-common -ffunction-sections -fdata-sections -fno-stack-protector
+CFLAGS		+=  $(ARCH_FLAGS)
+
+###############################################################################
+# Linker flags
+LDFLAGS		+= --static -nostartfiles -nostdlibs 
+LDFLAGS		+= -L$(LIB_DIR) -L$(TOOLCHLIB)
+LDFLAGS		+= -T$(LDSCRIPT)
+
+###############################################################################
+# Used libraries
+LDLIBS		+=  -lc $(shell $(CC) $(CFLAGS) -print-libgcc-file-name)
+
+DEFS		+= -DSTM32$(FAMILY) -DSTM32$(MCU) -DSTM32F10X_$(DENSITY)
+
+ELF		:= $(OBJDIR)/$(BINARY).elf
+LIST	:= $(OBJDIR)/$(BINARY).list
+BIN		:= $(BINARY).bin
+HEX		:= $(BINARY).hex
+
+all: $(OBJDIR)/RELEASE bin list size
+release: all
+
+debug: CFLAGS += -DEBUG -Werror
+debug: $(OBJDIR)/DEBUG bin list size
+
+$(OBJDIR)/DEBUG: 
+	@rm -rf $(OBJDIR)
+	@mkdir $(OBJDIR)
+	@> $(OBJDIR)/DEBUG
+	@echo "TARGET: DEBUG"
+	echo "CFLAGS += -DEBUG -Werror" > $(OBJDIR)/CFLAGS
+$(OBJDIR)/RELEASE:
+	@rm -rf $(OBJDIR)
+	@mkdir $(OBJDIR)
+	@> $(OBJDIR)/RELEASE
+	@echo "TARGET: RELEASE"
+	echo "" > $(OBJDIR)/CFLAGS
+
+elf: $(ELF)
+bin: $(BIN)
+hex: $(HEX)
+list: $(LIST)
+
+ifneq ($(MAKECMDGOALS),clean)
+-include $(DEPS)
+-include $(OBJDIR)/CFLAGS
+endif
+
+$(OBJDIR):
+	mkdir $(OBJDIR)
+
+$(STARTUP): $(INC_DIR)/startup/vector.c
+	$(CC) $(CFLAGS) $(DEFS) $(INCLUDE) -o $@ -c $<
+
+$(OBJDIR)/%.o: %.c
+	@echo "  CC      $<"
+	$(CC) $(CFLAGS) $(DEFS) $(INCLUDE) -o $@ -c $<
+
+$(BIN): $(ELF)
+	@echo "  OBJCOPY $(BIN)"
+	$(OBJCOPY) -Obinary $(ELF) $(BIN)
+
+$(HEX): $(ELF)
+	@echo "  OBJCOPY $(HEX)"
+	$(OBJCOPY) -Oihex $(ELF) $(HEX)
+
+$(LIST): $(ELF)
+	@echo "  OBJDUMP $(LIST)"
+	$(OBJDUMP) -S $(ELF) > $(LIST)
+
+$(ELF): $(OBJDIR) $(OBJS) 
+	@echo "  LD      $(ELF)"
+	$(LD) $(LDFLAGS) $(OBJS) $(LDLIBS) -o $(ELF)
+
+size: $(ELF)
+	$(SIZE) $(ELF)    
+
+clean:
+	@echo "  CLEAN"
+	@$(RM) $(HEX)
+	@$(RM) -rf $(OBJDIR) 2>/dev/null || true
+
+
+flash: $(BIN)
+	@echo "  FLASH  $(BIN)"
+	$(STFLASH) --reset write $(BIN) 0x8000000
+
+boot: $(BIN)
+	@echo "  LOAD $(BIN) through bootloader"
+	$(STBOOT) -b$(BOOTSPEED) $(BOOTPORT) -w $(BIN)
+
+dfuboot: $(BIN)
+	@echo "  LOAD  $(BIN) THROUGH DFU"
+	$(DFUUTIL) -a0 -D $(BIN) -s 0x08000000
+
+.PHONY: clean flash boot

F1:F103/CDC_ACM/Readme

@@ -0,0 +1 @@
+Base CDC snippet

F1:F103/CDC_ACM/hardware.c

@@ -0,0 +1,47 @@
+/*
+ *                                                                                                  geany_encoding=koi8-r
+ * hardware.c - hardware-dependent macros & functions
+ *
+ * Copyright 2018 Edward V. Emelianov <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ *
+ */
+
+#include "hardware.h"
+
+// pause in milliseconds for some purposes
+void pause_ms(uint32_t pause){
+    uint32_t Tnxt = Tms + pause;
+    while(Tms < Tnxt) nop();
+}
+
+static inline void gpio_setup(){
+    // Enable clocks to the GPIO subsystems (PB for ADC), turn on AFIO clocking to disable SWD/JTAG
+    RCC->APB2ENR |= RCC_APB2ENR_IOPAEN | RCC_APB2ENR_IOPCEN | RCC_APB2ENR_AFIOEN;
+    // turn off SWJ/JTAG
+//    AFIO->MAPR = AFIO_MAPR_SWJ_CFG_DISABLE;
+    // turn off USB pullup
+    GPIOA->ODR = (1<<13); // turn off usb pullup & turn on pullups for buttons
+    // Set led as opendrain output
+    GPIOC->CRH |= CRH(13, CNF_ODOUTPUT|MODE_SLOW);
+    // USB pullup (PA13) - opendrain output
+    GPIOA->CRH = CRH(13, CNF_ODOUTPUT|MODE_SLOW);
+}
+
+void hw_setup(){
+    gpio_setup();
+}

F1:F103/CDC_ACM/hardware.h

@@ -0,0 +1,48 @@
+/*
+ *                                                                                                  geany_encoding=koi8-r
+ * hardware.h
+ *
+ * Copyright 2018 Edward V. Emelianov <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ *
+ */
+#pragma once
+#ifndef __HARDWARE_H__
+#define __HARDWARE_H__
+
+#include "stm32f1.h"
+
+// LED0 - PC13 (bluepill), blinking each second
+#define LED0_port   GPIOC
+#define LED0_pin    (1<<13)
+
+// USB pullup (not present in bluepill) - PA13
+#define USBPU_port  GPIOA
+#define USBPU_pin   (1<<13)
+#define USBPU_ON()  pin_clear(USBPU_port, USBPU_pin)
+#define USBPU_OFF() pin_set(USBPU_port, USBPU_pin)
+
+#define LED_blink(x)    pin_toggle(x ## _port, x ## _pin)
+#define LED_on(x)       pin_clear(x ## _port, x ## _pin)
+#define LED_off(x)      pin_set(x ## _port, x ## _pin)
+
+extern volatile uint32_t Tms;
+
+void pause_ms(uint32_t pause);
+void hw_setup();
+
+#endif // __HARDWARE_H__

F1:F103/CDC_ACM/main.c

@@ -0,0 +1,146 @@
+/*
+ * main.c
+ *
+ * Copyright 2017 Edward V. Emelianoff <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+
+#include "hardware.h"
+#include "proto.h"
+#include "usb.h"
+#include "usb_lib.h"
+
+volatile uint32_t Tms = 0;
+
+/* Called when systick fires */
+void sys_tick_handler(void){
+    ++Tms;
+}
+
+void iwdg_setup(){
+    uint32_t tmout = 16000000;
+    /* Enable the peripheral clock RTC */
+    /* (1) Enable the LSI (40kHz) */
+    /* (2) Wait while it is not ready */
+    RCC->CSR |= RCC_CSR_LSION; /* (1) */
+    while((RCC->CSR & RCC_CSR_LSIRDY) != RCC_CSR_LSIRDY){if(--tmout == 0) break;} /* (2) */
+    /* Configure IWDG */
+    /* (1) Activate IWDG (not needed if done in option bytes) */
+    /* (2) Enable write access to IWDG registers */
+    /* (3) Set prescaler by 64 (1.6ms for each tick) */
+    /* (4) Set reload value to have a rollover each 2s */
+    /* (5) Check if flags are reset */
+    /* (6) Refresh counter */
+    IWDG->KR = IWDG_START; /* (1) */
+    IWDG->KR = IWDG_WRITE_ACCESS; /* (2) */
+    IWDG->PR = IWDG_PR_PR_1; /* (3) */
+    IWDG->RLR = 1250; /* (4) */
+    tmout = 16000000;
+    while(IWDG->SR){if(--tmout == 0) break;} /* (5) */
+    IWDG->KR = IWDG_REFRESH; /* (6) */
+}
+
+#define USBBUF 63
+// usb getline
+static char *get_USB(){
+    static char tmpbuf[USBBUF+1], *curptr = tmpbuf;
+    static int rest = USBBUF;
+    uint8_t x = USB_receive((uint8_t*)curptr);
+    if(!x) return NULL;
+    curptr[x] = 0;
+    if(x == 1 && *curptr == 0x7f){ // backspace
+        if(curptr > tmpbuf){
+            --curptr;
+            USND("\b \b");
+        }
+        return NULL;
+    }
+    USB_sendstr(curptr); // echo
+    if(curptr[x-1] == '\n'){ // || curptr[x-1] == '\r'){
+        curptr = tmpbuf;
+        rest = USBBUF;
+        // omit empty lines
+        if(tmpbuf[0] == '\n') return NULL;
+        // and wrong empty lines
+        if(tmpbuf[0] == '\r' && tmpbuf[1] == '\n') return NULL;
+        return tmpbuf;
+    }
+    curptr += x; rest -= x;
+    if(rest <= 0){ // buffer overflow
+        curptr = tmpbuf;
+        rest = USBBUF;
+    }
+    return NULL;
+}
+
+/* - these functions need for true USB-TTY
+static uint32_t newrate = 0;
+// redefine weak handlers
+void linecoding_handler(usb_LineCoding *lcd){
+    newrate = lcd->dwDTERate;
+}
+static uint16_t cl = 0xffff;
+void clstate_handler(uint16_t val){
+    cl = val;
+}
+static int8_t br = 0;
+void break_handler(){
+    br = 1;
+}*/
+
+int main(void){
+    uint32_t lastT = 0;
+    sysreset();
+    StartHSE();
+    SysTick_Config(72000);
+    hw_setup();
+
+    USBPU_OFF();
+/*    if(RCC->CSR & RCC_CSR_IWDGRSTF){ // watchdog reset occured
+        SEND("WDGRESET=1"); newline();
+    }
+    if(RCC->CSR & RCC_CSR_SFTRSTF){ // software reset occured
+        SEND("SOFTRESET=1"); newline();
+    }*/
+    RCC->CSR |= RCC_CSR_RMVF; // remove reset flags
+
+    USB_setup();
+    iwdg_setup();
+    USBPU_ON();
+
+    while (1){
+        IWDG->KR = IWDG_REFRESH; // refresh watchdog
+        if(Tms - lastT > 499){
+            LED_blink(LED0);
+            lastT = Tms;
+        }
+        usb_proc();
+        char *txt = get_USB();
+        if(txt){
+            IWDG->KR = IWDG_REFRESH;
+            cmd_parser(txt);
+        }
+        /*
+        int n = 0;
+        if(newrate){SEND("new speed: "); printu(newrate); n = 1; newrate = 0;}
+        if(cl!=0xffff){SEND("controls: "); printuhex(cl); n = 1; cl = 0xffff;}
+        if(br){SEND("break"); n = 1; br = 0;}
+        if(n){newline(); transmit_tbuf();}*/
+    }
+    return 0;
+}
+

F1:F103/CDC_ACM/proto.c

@@ -0,0 +1,205 @@
+/*
+ *                                                                                                  geany_encoding=koi8-r
+ * proto.c
+ *
+ * Copyright 2018 Edward V. Emelianov <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ *
+ */
+#include "hardware.h"
+#include "proto.h"
+#include "usb.h"
+
+#include <string.h> // strlen
+
+static char buff[BUFSZ+1], *bptr = buff;
+static uint8_t blen = 0;
+
+void sendbuf(){
+    IWDG->KR = IWDG_REFRESH;
+    if(blen == 0) return;
+    *bptr = 0;
+    USB_sendstr(buff);
+    bptr = buff;
+    blen = 0;
+}
+
+void bufputchar(char ch){
+    if(blen > BUFSZ-1){
+        sendbuf();
+    }
+    *bptr++ = ch;
+    ++blen;
+}
+
+void addtobuf(const char *txt){
+    IWDG->KR = IWDG_REFRESH;
+    while(*txt) bufputchar(*txt++);
+}
+
+char *omit_spaces(char *buf){
+    while(*buf){
+        if(*buf > ' ') break;
+        ++buf;
+    }
+    return buf;
+}
+
+// THERE'S NO OVERFLOW PROTECTION IN NUMBER READ PROCEDURES!
+// read decimal number
+static char *getdec(char *buf, uint32_t *N){
+    uint32_t num = 0;
+    while(*buf){
+        char c = *buf;
+        if(c < '0' || c > '9'){
+            break;
+        }
+        num *= 10;
+        num += c - '0';
+        ++buf;
+    }
+    *N = num;
+    return buf;
+}
+// read hexadecimal number (without 0x prefix!)
+static char *gethex(char *buf, uint32_t *N){
+    uint32_t num = 0;
+    while(*buf){
+        char c = *buf;
+        uint8_t M = 0;
+        if(c >= '0' && c <= '9'){
+            M = '0';
+        }else if(c >= 'A' && c <= 'F'){
+            M = 'A' - 10;
+        }else if(c >= 'a' && c <= 'f'){
+            M = 'a' - 10;
+        }
+        if(M){
+            num <<= 4;
+            num += c - M;
+        }else{
+            break;
+        }
+        ++buf;
+    }
+    *N = num;
+    return buf;
+}
+// read binary number (without 0b prefix!)
+static char *getbin(char *buf, uint32_t *N){
+    uint32_t num = 0;
+    while(*buf){
+        char c = *buf;
+        if(c < '0' || c > '1'){
+            break;
+        }
+        num <<= 1;
+        if(c == '1') num |= 1;
+        ++buf;
+    }
+    *N = num;
+    return buf;
+}
+
+/**
+ * @brief getnum - read uint32_t from string (dec, hex or bin: 127, 0x7f, 0b1111111)
+ * @param buf - buffer with number and so on
+ * @param N   - the number read
+ * @return pointer to first non-number symbol in buf (if it is == buf, there's no number)
+ */
+char *getnum(char *txt, uint32_t *N){
+    if(*txt == '0'){
+        if(txt[1] == 'x' || txt[1] == 'X') return gethex(txt+2, N);
+        if(txt[1] == 'b' || txt[1] == 'B') return getbin(txt+2, N);
+    }
+    return getdec(txt, N);
+}
+
+/**
+ * @brief cmd_parser - command parsing
+ * @param txt   - buffer with commands & data
+ * @param isUSB - == 1 if data got from USB
+ */
+void cmd_parser(char *txt){
+    char _1st = txt[0];
+    /*
+     * parse long commands here
+     */
+    /*switch(_1st){
+        case 'a':
+            addIGN(txt + 1);
+            goto eof;
+        break;
+    }*/
+    if(txt[1] != '\n') *txt = '?'; // help for wrong message length
+    switch(_1st){
+        case 'R':
+            SEND("Soft reset\n");
+            sendbuf();
+            pause_ms(5); // a little pause to transmit data
+            NVIC_SystemReset();
+        break;
+        case 'T':
+            SEND("Time (ms): ");
+            printu(Tms);
+            newline();
+        break;
+        default: // help
+            SEND(
+            "'R' - software reset\n"
+            "'T' - get time from start (ms)\n"
+            );
+        break;
+    }
+    newline();
+    sendbuf();
+}
+
+// print 32bit unsigned int
+void printu(uint32_t val){
+    char buf[11], *bufptr = &buf[10];
+    *bufptr = 0;
+    if(!val){
+        *(--bufptr) = '0';
+    }else{
+        while(val){
+            *(--bufptr) = val % 10 + '0';
+            val /= 10;
+        }
+    }
+    addtobuf(bufptr);
+}
+
+// print 32bit unsigned int as hex
+void printuhex(uint32_t val){
+    addtobuf("0x");
+    uint8_t *ptr = (uint8_t*)&val + 3;
+    int8_t i, j, z=1;
+    for(i = 0; i < 4; ++i, --ptr){
+        if(*ptr == 0){ // omit leading zeros
+            if(i == 3) z = 0;
+            if(z) continue;
+        }
+        else z = 0;
+        for(j = 1; j > -1; --j){
+            uint8_t half = (*ptr >> (4*j)) & 0x0f;
+            if(half < 10) bufputchar(half + '0');
+            else bufputchar(half - 10 + 'a');
+        }
+    }
+}
+

F1:F103/CDC_ACM/proto.h

@@ -0,0 +1,55 @@
+/*
+ *                                                                                                  geany_encoding=koi8-r
+ * proto.h
+ *
+ * Copyright 2018 Edward V. Emelianov <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ *
+ */
+#pragma once
+#ifndef __PROTO_H__
+#define __PROTO_H__
+
+#include "stm32f1.h"
+#include "hardware.h"
+
+#define BUFSZ   (64)
+
+// macro for static strings
+#define SEND(str) do{addtobuf(str);}while(0)
+
+#ifdef EBUG
+#define MSG(str)  do{addtobuf(__FILE__ " (L" STR(__LINE__) "): " str);}while(0)
+#else
+#define MSG(str)
+#endif
+
+#define newline() do{bufputchar('\n');}while(0)
+// newline with buffer sending over USART
+#define NL() do{bufputchar('\n'); sendbuf();}while(0)
+
+void cmd_parser(char *buf);
+void addtobuf(const char *txt);
+void bufputchar(char ch);
+void printu(uint32_t val);
+void printuhex(uint32_t val);
+void sendbuf();
+
+char *omit_spaces(char *buf);
+char *getnum(char *buf, uint32_t *N);
+
+#endif // __PROTO_H__

F1:F103/CDC_ACM/usb.c

@@ -0,0 +1,158 @@
+/*
+ *                                                                                                  geany_encoding=koi8-r
+ * usb.c - base functions for different USB types
+ *
+ * Copyright 2018 Edward V. Emelianov <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ *
+ */
+#include "usb.h"
+#include "usb_lib.h"
+
+static volatile uint8_t tx_succesfull = 1;
+static uint8_t rxNE = 0;
+
+static void rxtx_Handler(){
+    uint16_t epstatus = KEEP_DTOG(USB->EPnR[1]);
+    if(RX_FLAG(epstatus)){
+        rxNE = 1;
+        epstatus = (epstatus & ~(USB_EPnR_STAT_TX|USB_EPnR_CTR_RX)) ^ USB_EPnR_STAT_RX; // keep stat Tx & set valid RX, clear CTR Rx
+    }else{
+        tx_succesfull = 1;
+        epstatus = (epstatus & ~(USB_EPnR_STAT_TX|USB_EPnR_CTR_TX)) ^ USB_EPnR_STAT_RX; // keep stat Tx & set valid RX, clear CTR Tx
+    }
+    USB->EPnR[1] = epstatus;
+}
+
+void USB_setup(){
+    NVIC_DisableIRQ(USB_LP_CAN1_RX0_IRQn);
+    NVIC_DisableIRQ(USB_HP_CAN1_TX_IRQn);
+    RCC->APB1ENR |= RCC_APB1ENR_USBEN;
+    USB->CNTR   = USB_CNTR_FRES; // Force USB Reset
+    for(uint32_t ctr = 0; ctr < 72000; ++ctr) nop(); // wait >1ms
+    USB->CNTR   = 0;
+    USB->BTABLE = 0;
+    USB->DADDR  = 0;
+    USB->ISTR   = 0;
+    USB->CNTR   = USB_CNTR_RESETM | USB_CNTR_WKUPM; // allow only wakeup & reset interrupts
+    NVIC_EnableIRQ(USB_LP_CAN1_RX0_IRQn);
+}
+
+
+static int usbwr(const uint8_t *buf, uint16_t l){
+    uint32_t ctra = 1000000;
+    while(--ctra && tx_succesfull == 0){
+        IWDG->KR = IWDG_REFRESH;
+    }
+    tx_succesfull = 0;
+    EP_Write(1, buf, l);
+    ctra = 1000000;
+    while(--ctra && tx_succesfull == 0){
+        IWDG->KR = IWDG_REFRESH;
+    }
+    if(tx_succesfull == 0){usbON = 0; return 1;} // usb is OFF?
+    return 0;
+}
+
+static uint8_t usbbuff[USB_TXBUFSZ-1]; // temporary buffer (63 - to prevent need of ZLP)
+static uint8_t buflen = 0; // amount of symbols in usbbuff
+
+// send next up to 64 bytes of data in usbbuff
+static void send_next(){
+    if(!buflen || !tx_succesfull) return;
+    tx_succesfull = 0;
+    EP_Write(1, usbbuff, buflen);
+    buflen = 0;
+}
+
+// unblocking sending - just fill a buffer
+void USB_send(const uint8_t *buf, uint16_t len){
+    if(!usbON || !len) return;
+    if(len > USB_TXBUFSZ-1 - buflen){
+        usbwr(usbbuff, buflen);
+        buflen = 0;
+    }
+    if(len > USB_TXBUFSZ-1){
+        USB_send_blk(buf, len);
+        return;
+    }
+    while(len--) usbbuff[buflen++] = *buf++;
+}
+
+// send zero-terminated string
+void USB_sendstr(const char *str){
+    uint16_t l = 0;
+    const char *ptr = str;
+    while(*ptr++) ++l;
+    USB_send((uint8_t*)str, l);
+}
+
+// blocking sending
+void USB_send_blk(const uint8_t *buf, uint16_t len){
+    if(!usbON || !len) return; // USB disconnected
+    if(buflen){
+        usbwr(usbbuff, buflen);
+        buflen = 0;
+    }
+    int needzlp = 0;
+    while(len){
+        if(len == USB_TXBUFSZ) needzlp = 1;
+        uint16_t s = (len > USB_TXBUFSZ) ? USB_TXBUFSZ : len;
+        if(usbwr(buf, s)) return;
+        len -= s;
+        buf += s;
+    }  
+    if(needzlp){
+        usbwr(NULL, 0);
+    }
+}
+
+void usb_proc(){
+    switch(USB_Dev.USB_Status){
+        case USB_STATE_CONFIGURED:
+            // make new BULK endpoint
+            // Buffer have 1024 bytes, but last 256 we use for CAN bus (30.2 of RM: USB main features)
+            //EP_Init(1, EP_TYPE_INTERRUPT, USB_EP1BUFSZ, 0, EP1_Handler); // IN1 - transmit
+            EP_Init(1, EP_TYPE_BULK, USB_TXBUFSZ, USB_RXBUFSZ, rxtx_Handler); // INOUT1 - transmit/receive data
+            USB_Dev.USB_Status = USB_STATE_CONNECTED;
+        break;
+        case USB_STATE_DEFAULT:
+        case USB_STATE_ADDRESSED:
+            if(usbON){
+                usbON = 0;
+            }
+        break;
+        default: // USB_STATE_CONNECTED - send next data portion
+            if(!usbON) return;
+            send_next();
+    }
+}
+
+/**
+ * @brief USB_receive
+ * @param buf (i) - buffer[64] for received data
+ * @return amount of received bytes
+ */
+uint8_t USB_receive(uint8_t *buf){
+    if(!usbON || !rxNE) return 0;
+    uint8_t sz = EP_Read(1, (uint16_t*)buf);
+    uint16_t epstatus = KEEP_DTOG(USB->EPnR[1]);
+    // keep stat_tx & set ACK rx
+    USB->EPnR[1] = (epstatus & ~(USB_EPnR_STAT_TX)) ^ USB_EPnR_STAT_RX;
+    rxNE = 0;
+    return sz;
+}

F1:F103/CDC_ACM/usb.h

@@ -0,0 +1,39 @@
+/*
+ *                                                                                                  geany_encoding=koi8-r
+ * usb.h
+ *
+ * Copyright 2018 Edward V. Emelianov <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ *
+ */
+#pragma once
+#ifndef __USB_H__
+#define __USB_H__
+
+#include "hardware.h"
+
+// send string with constant length
+#define USND(str)  do{USB_send((uint8_t*)str, sizeof(str)-1);}while(0)
+
+void USB_setup();
+void usb_proc();
+void USB_send(const uint8_t *buf, uint16_t len);
+void USB_sendstr(const char *str);
+void USB_send_blk(const uint8_t *buf, uint16_t len);
+uint8_t USB_receive(uint8_t *buf);
+
+#endif // __USB_H__

F1:F103/CDC_ACM/usb_defs.h

@@ -0,0 +1,107 @@
+/*
+ *                                                                                                  geany_encoding=koi8-r
+ * usb_defs.h
+ *
+ * Copyright 2018 Edward V. Emelianov <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ *
+ */
+
+#pragma once
+#ifndef __USB_DEFS_H__
+#define __USB_DEFS_H__
+
+#include <stm32f1.h>
+
+// max endpoints number
+#define STM32ENDPOINTS          8
+/**
+ *                 Buffers size definition
+ **/
+#define USB_BTABLE_SIZE         512
+// first 64 bytes of USB_BTABLE are registers!
+//#define USB_EP0_BASEADDR        64
+// for USB FS EP0 buffers are from 8 to 64 bytes long (64 for PL2303)
+#define USB_EP0_BUFSZ           64
+// USB transmit buffer size (64 for PL2303)
+#define USB_TXBUFSZ             64
+// USB receive buffer size (64 for PL2303)
+#define USB_RXBUFSZ             64
+// EP1 - interrupt - buffer size
+#define USB_EP1BUFSZ            8
+
+#define USB_BTABLE_BASE         0x40006000
+#define USB_BASE                ((uint32_t)0x40005C00)
+#define USB                     ((USB_TypeDef *) USB_BASE)
+
+#ifdef USB_BTABLE
+#undef USB_BTABLE
+#endif
+#define USB_BTABLE              ((USB_BtableDef *)(USB_BTABLE_BASE))
+#define USB_ISTR_EPID           0x0000000F
+#define USB_FNR_LSOF_0          0x00000800
+#define USB_FNR_lSOF_1          0x00001000
+#define USB_LPMCSR_BESL_0       0x00000010
+#define USB_LPMCSR_BESL_1       0x00000020
+#define USB_LPMCSR_BESL_2       0x00000040
+#define USB_LPMCSR_BESL_3       0x00000080
+#define USB_EPnR_CTR_RX         0x00008000
+#define USB_EPnR_DTOG_RX        0x00004000
+#define USB_EPnR_STAT_RX        0x00003000
+#define USB_EPnR_STAT_RX_0      0x00001000
+#define USB_EPnR_STAT_RX_1      0x00002000
+#define USB_EPnR_SETUP          0x00000800
+#define USB_EPnR_EP_TYPE        0x00000600
+#define USB_EPnR_EP_TYPE_0      0x00000200
+#define USB_EPnR_EP_TYPE_1      0x00000400
+#define USB_EPnR_EP_KIND        0x00000100
+#define USB_EPnR_CTR_TX         0x00000080
+#define USB_EPnR_DTOG_TX        0x00000040
+#define USB_EPnR_STAT_TX        0x00000030
+#define USB_EPnR_STAT_TX_0      0x00000010
+#define USB_EPnR_STAT_TX_1      0x00000020
+#define USB_EPnR_EA             0x0000000F
+#define USB_COUNTn_RX_BLSIZE    0x00008000
+#define USB_COUNTn_NUM_BLOCK    0x00007C00
+#define USB_COUNTn_RX           0x0000003F
+
+#ifdef USB_TypeDef
+#define USB_TypeDef USB_TypeDef_custom
+#endif
+
+typedef struct {
+    __IO uint32_t EPnR[STM32ENDPOINTS];
+    __IO uint32_t RESERVED[STM32ENDPOINTS];
+    __IO uint32_t CNTR;
+    __IO uint32_t ISTR;
+    __IO uint32_t FNR;
+    __IO uint32_t DADDR;
+    __IO uint32_t BTABLE;
+} USB_TypeDef;
+
+typedef struct{
+    __IO uint32_t USB_ADDR_TX;
+    __IO uint32_t USB_COUNT_TX;
+    __IO uint32_t USB_ADDR_RX;
+    __IO uint32_t USB_COUNT_RX;
+} USB_EPDATA_TypeDef;
+
+typedef struct{
+    __IO USB_EPDATA_TypeDef EP[STM32ENDPOINTS];
+} USB_BtableDef;
+
+#endif // __USB_DEFS_H__

F1:F103/CDC_ACM/usb_lib.c

@@ -0,0 +1,489 @@
+/*
+ *                                                                                                  geany_encoding=koi8-r
+ * usb_lib.c
+ *
+ * Copyright 2018 Edward V. Emelianov <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ *
+ */
+
+#include <stdint.h>
+#include "usb_lib.h"
+
+ep_t endpoints[STM32ENDPOINTS];
+
+usb_dev_t USB_Dev;
+static usb_LineCoding lineCoding = {115200, 0, 0, 8};
+static config_pack_t setup_packet;
+static uint8_t ep0databuf[EP0DATABUF_SIZE];
+static uint8_t ep0dbuflen = 0;
+
+usb_LineCoding getLineCoding(){return lineCoding;}
+
+uint8_t usbON = 0; // device disconnected from terminal
+
+// definition of parts common for USB_DeviceDescriptor & USB_DeviceQualifierDescriptor
+#define bcdUSB_L        0x00
+#define bcdUSB_H        0x02
+#define bDeviceClass    0
+#define bDeviceSubClass 0
+#define bDeviceProtocol 0
+#define bNumConfigurations 1
+
+static const uint8_t USB_DeviceDescriptor[] = {
+        18,     // bLength
+        0x01,   // bDescriptorType - Device descriptor
+        bcdUSB_L,   // bcdUSB_L - 1.10
+        bcdUSB_H,   // bcdUSB_H
+        bDeviceClass,   // bDeviceClass - USB_COMM
+        bDeviceSubClass,   // bDeviceSubClass
+        bDeviceProtocol,   // bDeviceProtocol
+        USB_EP0_BUFSZ,   // bMaxPacketSize
+  // 0483:5740 (VID:PID) - stm32 VCP
+    0x83, 0x04, 0x40, 0x57,
+        0x00,   // bcdDevice_Ver_L
+        0x02,   // bcdDevice_Ver_H
+        0x01,   // iManufacturer
+        0x02,   // iProduct
+        0x03,   // iSerialNumber
+        bNumConfigurations    // bNumConfigurations
+};
+
+static const uint8_t USB_DeviceQualifierDescriptor[] = {
+        10,     //bLength
+        0x06,   // bDescriptorType - Device qualifier
+        bcdUSB_L,   // bcdUSB_L
+        bcdUSB_H,   // bcdUSB_H
+        bDeviceClass,   // bDeviceClass
+        bDeviceSubClass,   // bDeviceSubClass
+        bDeviceProtocol,   // bDeviceProtocol
+        USB_EP0_BUFSZ,   // bMaxPacketSize0
+        bNumConfigurations,   // bNumConfigurations
+        0x00    // Reserved
+};
+
+static const uint8_t USB_ConfigDescriptor[] = {
+    /*Configuration Descriptor*/
+    0x09, /* bLength: Configuration Descriptor size */
+    0x02, /* bDescriptorType: Configuration */
+    67,   /* wTotalLength:no of returned bytes */
+    0x00,
+    0x02, /* bNumInterfaces: 2 interface */
+    0x01, /* bConfigurationValue: Configuration value */
+    0x00, /* iConfiguration: Index of string descriptor describing the configuration */
+    0x80, /* bmAttributes - Bus powered */
+    0x32, /* MaxPower 100 mA */
+    /*---------------------------------------------------------------------------*/
+    /*Interface Descriptor */
+    0x09, /* bLength: Interface Descriptor size */
+    0x04, /* bDescriptorType: Interface */
+    0x00, /* bInterfaceNumber: Number of Interface */
+    0x00, /* bAlternateSetting: Alternate setting */
+    0x01, /* bNumEndpoints: One endpoints used */
+    0x02, /* bInterfaceClass: Communication Interface Class */
+    0x02, /* bInterfaceSubClass: Abstract Control Model */
+    0x01, /* bInterfaceProtocol: Common AT commands */
+    0x00, /* iInterface: */
+    /*Header Functional Descriptor*/
+    0x05, /* bLength: Endpoint Descriptor size */
+    0x24, /* bDescriptorType: CS_INTERFACE */
+    0x00, /* bDescriptorSubtype: Header Func Desc */
+    0x10, /* bcdCDC: spec release number */
+    0x01,
+    /*Call Management Functional Descriptor*/
+    0x05, /* bFunctionLength */
+    0x24, /* bDescriptorType: CS_INTERFACE */
+    0x01, /* bDescriptorSubtype: Call Management Func Desc */
+    0x00, /* bmCapabilities: D0+D1 */
+    0x01, /* bDataInterface: 1 */
+    /*ACM Functional Descriptor*/
+    0x04, /* bFunctionLength */
+    0x24, /* bDescriptorType: CS_INTERFACE */
+    0x02, /* bDescriptorSubtype: Abstract Control Management desc */
+    0x02, /* bmCapabilities */
+    /*Union Functional Descriptor*/
+    0x05, /* bFunctionLength */
+    0x24, /* bDescriptorType: CS_INTERFACE */
+    0x06, /* bDescriptorSubtype: Union func desc */
+    0x00, /* bMasterInterface: Communication class interface */
+    0x01, /* bSlaveInterface0: Data Class Interface */
+    /*Endpoint 1 Descriptor*/
+    0x07, /* bLength: Endpoint Descriptor size */
+    0x05, /* bDescriptorType: Endpoint */
+    0x8A, /* bEndpointAddress IN10 */
+    0x03, /* bmAttributes: Interrupt */
+    (USB_EP1BUFSZ & 0xff), /* wMaxPacketSize LO: */
+    (USB_EP1BUFSZ >> 8), /* wMaxPacketSize HI: */
+    0x10, /* bInterval: */
+    /*---------------------------------------------------------------------------*/
+    /*Data class interface descriptor*/
+    0x09, /* bLength: Endpoint Descriptor size */
+    0x04, /* bDescriptorType: */
+    0x01, /* bInterfaceNumber: Number of Interface */
+    0x00, /* bAlternateSetting: Alternate setting */
+    0x02, /* bNumEndpoints: Two endpoints used */
+    0x0A, /* bInterfaceClass: CDC */
+    0x02, /* bInterfaceSubClass: */
+    0x00, /* bInterfaceProtocol: */
+    0x00, /* iInterface: */
+    /*Endpoint IN3 Descriptor*/
+    0x07, /* bLength: Endpoint Descriptor size */
+    0x05, /* bDescriptorType: Endpoint */
+    0x81, /* bEndpointAddress: IN1 */
+    0x02, /* bmAttributes: Bulk */
+    (USB_TXBUFSZ & 0xff), /* wMaxPacketSize: 64 */
+    (USB_TXBUFSZ >> 8),
+    0x00, /* bInterval: ignore for Bulk transfer */
+    /*Endpoint OUT1 Descriptor*/
+    0x07, /* bLength: Endpoint Descriptor size */
+    0x05, /* bDescriptorType: Endpoint */
+    0x01, /* bEndpointAddress: OUT1 */
+    0x02, /* bmAttributes: Bulk */
+    (USB_TXBUFSZ & 0xff), /* wMaxPacketSize: 64 */
+    (USB_TXBUFSZ >> 8),
+    0x00 /* bInterval: ignore for Bulk transfer */
+};
+
+
+USB_LANG_ID(USB_StringLangDescriptor, LANG_US);
+
+USB_STRING(USB_StringSerialDescriptor, u"000001");
+USB_STRING(USB_StringManufacturingDescriptor, u"Eddy @ SAO RAS");
+USB_STRING(USB_StringProdDescriptor, u"USB-Serial Controller");
+
+/*
+ * default handlers
+ */
+// SET_LINE_CODING
+void WEAK linecoding_handler(usb_LineCoding __attribute__((unused)) *lcd){
+    //MSG("linecoding_handler()");
+}
+
+// SET_CONTROL_LINE_STATE
+void WEAK clstate_handler(uint16_t __attribute__((unused)) val){
+    //MSG("clstate_handler()");
+}
+
+// SEND_BREAK
+void WEAK break_handler(){
+    //MSG("break_handler()");
+}
+
+static void wr0(const uint8_t *buf, uint16_t size){
+    if(setup_packet.wLength < size) size = setup_packet.wLength; // shortened request
+    if(size < endpoints[0].txbufsz){
+        EP_WriteIRQ(0, buf, size);
+        return;
+    }
+    while(size){
+        uint16_t l = size;
+        if(l > endpoints[0].txbufsz) l = endpoints[0].txbufsz;
+        EP_WriteIRQ(0, buf, l);
+        buf += l;
+        size -= l;
+        uint8_t needzlp = (l == endpoints[0].txbufsz) ? 1 : 0;
+        if(size || needzlp){ // send last data buffer
+            uint16_t status = KEEP_DTOG(USB->EPnR[0]);
+            // keep DTOGs, clear CTR_RX,TX, set TX VALID, leave stat_Rx
+            USB->EPnR[0] = (status & ~(USB_EPnR_CTR_RX|USB_EPnR_CTR_TX|USB_EPnR_STAT_RX))
+                            ^ USB_EPnR_STAT_TX;
+            uint32_t ctr = 1000000;
+            while(--ctr && (USB->ISTR & USB_ISTR_CTR) == 0){IWDG->KR = IWDG_REFRESH;};
+            if((USB->ISTR & USB_ISTR_CTR) == 0){
+                return;
+            }
+            if(needzlp) EP_WriteIRQ(0, (uint8_t*)0, 0);
+        }
+    }
+}
+
+static inline void get_descriptor(){
+    switch(setup_packet.wValue){
+        case DEVICE_DESCRIPTOR:
+            wr0(USB_DeviceDescriptor, sizeof(USB_DeviceDescriptor));
+        break;
+        case CONFIGURATION_DESCRIPTOR:
+            wr0(USB_ConfigDescriptor, sizeof(USB_ConfigDescriptor));
+        break;
+        case STRING_LANG_DESCRIPTOR:
+            wr0((const uint8_t *)&USB_StringLangDescriptor, STRING_LANG_DESCRIPTOR_SIZE_BYTE);
+        break;
+        case STRING_MAN_DESCRIPTOR:
+            wr0((const uint8_t *)&USB_StringManufacturingDescriptor, USB_StringManufacturingDescriptor.bLength);
+        break;
+        case STRING_PROD_DESCRIPTOR:
+            wr0((const uint8_t *)&USB_StringProdDescriptor, USB_StringProdDescriptor.bLength);
+        break;
+        case STRING_SN_DESCRIPTOR:
+            wr0((const uint8_t *)&USB_StringSerialDescriptor, USB_StringSerialDescriptor.bLength);
+        break;
+        case DEVICE_QUALIFIER_DESCRIPTOR:
+            wr0(USB_DeviceQualifierDescriptor, USB_DeviceQualifierDescriptor[0]);
+        break;
+        default:
+        break;
+    }
+}
+
+static uint8_t configuration = 0; // reply for GET_CONFIGURATION (==1 if configured)
+static inline void std_d2h_req(){
+    uint16_t state = 0; // bus powered
+    switch(setup_packet.bRequest){
+        case GET_DESCRIPTOR:
+            get_descriptor();
+        break;
+        case GET_STATUS:
+            EP_WriteIRQ(0, (uint8_t *)&state, 2); // send status: Bus Powered
+        break;
+        case GET_CONFIGURATION:
+            EP_WriteIRQ(0, &configuration, 1);
+        break;
+        default:
+        break;
+    }
+}
+
+static inline void std_h2d_req(){
+    switch(setup_packet.bRequest){
+        case SET_ADDRESS:
+            // new address will be assigned later - after  acknowlegement or request to host
+            USB_Dev.USB_Addr = setup_packet.wValue;
+        break;
+        case SET_CONFIGURATION:
+            // Now device configured
+            USB_Dev.USB_Status = USB_STATE_CONFIGURED;
+            configuration = setup_packet.wValue;
+        break;
+        default:
+        break;
+    }
+}
+
+/*
+bmRequestType: 76543210
+7    direction: 0 - host->device, 1 - device->host
+65   type: 0 - standard, 1 - class, 2 - vendor
+4..0 getter: 0 - device, 1 - interface, 2 - endpoint, 3 - other
+*/
+/**
+ * Endpoint0 (control) handler
+ */
+static void EP0_Handler(){
+    uint8_t reqtype = setup_packet.bmRequestType & 0x7f;
+    uint8_t dev2host = (setup_packet.bmRequestType & 0x80) ? 1 : 0;
+    uint16_t epstatus = USB->EPnR[0];
+    int rxflag = RX_FLAG(epstatus);
+    if(rxflag && SETUP_FLAG(epstatus)){
+        switch(reqtype){
+            case STANDARD_DEVICE_REQUEST_TYPE: // standard device request
+                if(dev2host){
+                    std_d2h_req();
+                }else{
+                    std_h2d_req();
+                    EP_WriteIRQ(0, (uint8_t *)0, 0);
+                }
+            break;
+            case STANDARD_ENDPOINT_REQUEST_TYPE: // standard endpoint request
+                if(setup_packet.bRequest == CLEAR_FEATURE){
+                    EP_WriteIRQ(0, (uint8_t *)0, 0);
+                }else{
+                }
+            break;
+            case CONTROL_REQUEST_TYPE:
+                switch(setup_packet.bRequest){
+                    case GET_LINE_CODING:
+                        EP_WriteIRQ(0, (uint8_t*)&lineCoding, sizeof(lineCoding));
+                    break;
+                    case SET_LINE_CODING: // omit this for next stage, when data will come
+                    break;
+                    case SET_CONTROL_LINE_STATE:
+                        usbON = 1;
+                        clstate_handler(setup_packet.wValue);
+                    break;
+                    case SEND_BREAK:
+                        usbON = 0;
+                        break_handler();
+                    break;
+                    default:
+                    break;
+                }
+                if(setup_packet.bRequest != GET_LINE_CODING) EP_WriteIRQ(0, (uint8_t *)0, 0);
+            break;
+            default:
+                EP_WriteIRQ(0, (uint8_t *)0, 0);
+        }
+    }else if(rxflag){ // got data over EP0 or host acknowlegement
+        if(endpoints[0].rx_cnt){
+            if(setup_packet.bRequest == SET_LINE_CODING){
+                linecoding_handler((usb_LineCoding*)ep0databuf);
+            }
+        }
+    }else if(TX_FLAG(epstatus)){ // package transmitted
+        // now we can change address after enumeration
+        if((USB->DADDR & USB_DADDR_ADD) != USB_Dev.USB_Addr){
+            USB->DADDR = USB_DADDR_EF | USB_Dev.USB_Addr;
+            // change state to ADRESSED
+            USB_Dev.USB_Status = USB_STATE_ADDRESSED;
+        }
+    }
+    epstatus = KEEP_DTOG(USB->EPnR[0]);
+    if(rxflag) epstatus ^= USB_EPnR_STAT_TX; // start ZLP/data transmission
+    else epstatus &= ~USB_EPnR_STAT_TX; // or leave unchanged
+    // keep DTOGs, clear CTR_RX,TX, set RX VALID
+    USB->EPnR[0] = (epstatus & ~(USB_EPnR_CTR_RX|USB_EPnR_CTR_TX)) ^ USB_EPnR_STAT_RX;
+}
+
+static uint16_t lastaddr = LASTADDR_DEFAULT;
+/**
+ * Endpoint initialisation
+ * @param number - EP num (0...7)
+ * @param type - EP type (EP_TYPE_BULK, EP_TYPE_CONTROL, EP_TYPE_ISO, EP_TYPE_INTERRUPT)
+ * @param txsz - transmission buffer size @ USB/CAN buffer
+ * @param rxsz - reception buffer size @ USB/CAN buffer
+ * @param uint16_t (*func)(ep_t *ep) - EP handler function
+ * @return 0 if all OK
+ */
+int EP_Init(uint8_t number, uint8_t type, uint16_t txsz, uint16_t rxsz, void (*func)(ep_t ep)){
+    if(number >= STM32ENDPOINTS) return 4; // out of configured amount
+    if(txsz > USB_BTABLE_SIZE || rxsz > USB_BTABLE_SIZE) return 1; // buffer too large
+    if(lastaddr + txsz + rxsz >= USB_BTABLE_SIZE) return 2; // out of btable
+    USB->EPnR[number] = (type << 9) | (number & USB_EPnR_EA);
+    USB->EPnR[number] ^= USB_EPnR_STAT_RX | USB_EPnR_STAT_TX_1;
+    if(rxsz & 1 || rxsz > 512) return 3; // wrong rx buffer size
+    uint16_t countrx = 0;
+    if(rxsz < 64) countrx = rxsz / 2;
+    else{
+        if(rxsz & 0x1f) return 3; // should be multiple of 32
+        countrx = 31 + rxsz / 32;
+    }
+    USB_BTABLE->EP[number].USB_ADDR_TX = lastaddr;
+    endpoints[number].tx_buf = (uint16_t *)(USB_BTABLE_BASE + lastaddr*2);
+    endpoints[number].txbufsz = txsz;
+    lastaddr += txsz;
+    USB_BTABLE->EP[number].USB_COUNT_TX = 0;
+    USB_BTABLE->EP[number].USB_ADDR_RX = lastaddr;
+    endpoints[number].rx_buf = (uint16_t *)(USB_BTABLE_BASE + lastaddr*2);
+    lastaddr += rxsz;
+    USB_BTABLE->EP[number].USB_COUNT_RX = countrx << 10;
+    endpoints[number].func = func;
+    return 0;
+}
+
+//extern int8_t dump;
+// standard IRQ handler
+void usb_lp_can_rx0_isr(){
+    if(USB->ISTR & USB_ISTR_RESET){
+        usbON = 0;
+        // Reinit registers
+        USB->CNTR = USB_CNTR_RESETM | USB_CNTR_CTRM | USB_CNTR_SUSPM | USB_CNTR_WKUPM;
+        // Endpoint 0 - CONTROL
+        // ON USB LS size of EP0 may be 8 bytes, but on FS it should be 64 bytes!
+        lastaddr = LASTADDR_DEFAULT;
+        // clear address, leave only enable bit
+        USB->DADDR = USB_DADDR_EF;
+        // state is default - wait for enumeration
+        USB_Dev.USB_Status = USB_STATE_DEFAULT;
+        USB->ISTR = ~USB_ISTR_RESET;
+        if(EP_Init(0, EP_TYPE_CONTROL, USB_EP0_BUFSZ, USB_EP0_BUFSZ, EP0_Handler)){
+            return;
+        }
+    }
+    if(USB->ISTR & USB_ISTR_CTR){
+        // EP number
+        uint8_t n = USB->ISTR & USB_ISTR_EPID;
+        // copy status register
+        uint16_t epstatus = USB->EPnR[n];
+        // copy received bytes amount
+        endpoints[n].rx_cnt = USB_BTABLE->EP[n].USB_COUNT_RX & 0x3FF; // low 10 bits is counter
+        // check direction
+        if(USB->ISTR & USB_ISTR_DIR){ // OUT interrupt - receive data, CTR_RX==1 (if CTR_TX == 1 - two pending transactions: receive following by transmit)
+            if(n == 0){ // control endpoint
+                if(epstatus & USB_EPnR_SETUP){ // setup packet -> copy data to conf_pack
+                    EP_Read(0, (uint16_t*)&setup_packet);
+                    ep0dbuflen = 0;
+                    // interrupt handler will be called later
+                }else if(epstatus & USB_EPnR_CTR_RX){ // data packet -> push received data to ep0databuf
+                    ep0dbuflen = endpoints[0].rx_cnt;
+                    EP_Read(0, (uint16_t*)&ep0databuf);
+                }
+            }
+        }else{ // IN interrupt - transmit data, only CTR_TX == 1
+            // enumeration end could be MSG (if EP0)
+        }
+        // call EP handler
+        if(endpoints[n].func) endpoints[n].func(endpoints[n]);
+    }
+    if(USB->ISTR & USB_ISTR_SUSP){ // suspend -> still no connection, may sleep
+        usbON = 0;
+        USB->CNTR |= USB_CNTR_FSUSP | USB_CNTR_LP_MODE;
+        USB->ISTR = ~USB_ISTR_SUSP;
+    }
+    if(USB->ISTR & USB_ISTR_WKUP){ // wakeup
+        USB->CNTR &= ~(USB_CNTR_FSUSP | USB_CNTR_LP_MODE); // clear suspend flags
+        USB->ISTR = ~USB_ISTR_WKUP;
+    }
+}
+
+/**
+ * Write data to EP buffer (called from IRQ handler)
+ * @param number - EP number
+ * @param *buf - array with data
+ * @param size - its size
+ */
+void EP_WriteIRQ(uint8_t number, const uint8_t *buf, uint16_t size){
+    uint8_t i;
+    if(size > endpoints[number].txbufsz) size = endpoints[number].txbufsz;
+    uint16_t N2 = (size + 1) >> 1;
+    // the buffer is 16-bit, so we should copy data as it would be uint16_t
+    uint16_t *buf16 = (uint16_t *)buf;
+    uint32_t *out = (uint32_t *)endpoints[number].tx_buf;
+    for(i = 0; i < N2; ++i, ++out){
+        *out = buf16[i];
+    }
+    USB_BTABLE->EP[number].USB_COUNT_TX = size;
+}
+
+/**
+ * Write data to EP buffer (called outside IRQ handler)
+ * @param number - EP number
+ * @param *buf - array with data
+ * @param size - its size
+ */
+void EP_Write(uint8_t number, const uint8_t *buf, uint16_t size){
+    EP_WriteIRQ(number, buf, size);
+    uint16_t status = KEEP_DTOG(USB->EPnR[number]);
+    // keep DTOGs, clear CTR_TX & set TX VALID to start transmission
+    USB->EPnR[number] = (status & ~(USB_EPnR_CTR_TX)) ^ USB_EPnR_STAT_TX;
+}
+
+/*
+ * Copy data from EP buffer into user buffer area
+ * @param *buf - user array for data
+ * @return amount of data read
+ */
+int EP_Read(uint8_t number, uint16_t *buf){
+    int sz = endpoints[number].rx_cnt;
+    if(!sz) return 0;
+    endpoints[number].rx_cnt = 0;
+    int n = (sz + 1) >> 1;
+    uint32_t *in = (uint32_t *)endpoints[number].rx_buf;
+    if(n){
+        for(int i = 0; i < n; ++i, ++in)
+            buf[i] = *(uint16_t*)in;
+    }
+    return sz;
+}

F1:F103/CDC_ACM/usb_lib.h

@@ -0,0 +1,215 @@
+/*
+ *                                                                                                  geany_encoding=koi8-r
+ * usb_lib.h
+ *
+ * Copyright 2018 Edward V. Emelianov <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ *
+ */
+
+#pragma once
+#ifndef __USB_LIB_H__
+#define __USB_LIB_H__
+
+#include <wchar.h>
+#include "usb_defs.h"
+
+#define EP0DATABUF_SIZE                 (64)
+#define LASTADDR_DEFAULT                (STM32ENDPOINTS * 8)
+
+// Max EP amount (EP0 + other used)
+//#define ENDPOINTS_NUM                   4
+// bmRequestType & 0x7f
+#define STANDARD_DEVICE_REQUEST_TYPE    0
+#define STANDARD_ENDPOINT_REQUEST_TYPE  2
+#define VENDOR_REQUEST_TYPE             0x40
+#define CONTROL_REQUEST_TYPE            0x21
+// bRequest, standard; for bmRequestType == 0x80
+#define GET_STATUS                      0x00
+#define GET_DESCRIPTOR                  0x06
+#define GET_CONFIGURATION               0x08
+// for bmRequestType == 0
+#define CLEAR_FEATURE                   0x01
+#define SET_FEATURE                     0x03    // unused
+#define SET_ADDRESS                     0x05
+#define SET_DESCRIPTOR                  0x07    // unused
+#define SET_CONFIGURATION               0x09
+// for bmRequestType == 0x81, 1 or 0xB2
+#define GET_INTERFACE                   0x0A    // unused
+#define SET_INTERFACE                   0x0B    // unused
+#define SYNC_FRAME                      0x0C    // unused
+#define VENDOR_REQUEST                  0x01    // unused
+
+// Class-Specific Control Requests
+#define SEND_ENCAPSULATED_COMMAND       0x00    // unused
+#define GET_ENCAPSULATED_RESPONSE       0x01    // unused
+#define SET_COMM_FEATURE                0x02    // unused
+#define GET_COMM_FEATURE                0x03    // unused
+#define CLEAR_COMM_FEATURE              0x04    // unused
+#define SET_LINE_CODING                 0x20
+#define GET_LINE_CODING                 0x21
+#define SET_CONTROL_LINE_STATE          0x22
+#define SEND_BREAK                      0x23
+
+// control line states
+#define CONTROL_DTR                     0x01
+#define CONTROL_RTS                     0x02
+
+// wValue
+#define DEVICE_DESCRIPTOR               0x100
+#define CONFIGURATION_DESCRIPTOR        0x200
+#define STRING_LANG_DESCRIPTOR          0x300
+#define STRING_MAN_DESCRIPTOR           0x301
+#define STRING_PROD_DESCRIPTOR          0x302
+#define STRING_SN_DESCRIPTOR            0x303
+#define DEVICE_QUALIFIER_DESCRIPTOR     0x600
+
+#define RX_FLAG(epstat)                 (epstat & USB_EPnR_CTR_RX)
+#define TX_FLAG(epstat)                 (epstat & USB_EPnR_CTR_TX)
+#define SETUP_FLAG(epstat)              (epstat & USB_EPnR_SETUP)
+
+// keep all DTOGs and STATs
+#define KEEP_DTOG_STAT(EPnR)            (EPnR & ~(USB_EPnR_STAT_RX|USB_EPnR_STAT_TX|USB_EPnR_DTOG_RX|USB_EPnR_DTOG_TX))
+#define KEEP_DTOG(EPnR)                 (EPnR & ~(USB_EPnR_DTOG_RX|USB_EPnR_DTOG_TX))
+
+//#define RX_CNT(N)                       (USB_BTABLE->EP[N].USB_COUNT_RX & 0x3FF)
+
+/*
+// EPnR bits manipulation
+#define CLEAR_DTOG_RX(R)                (R & USB_EPnR_DTOG_RX) ? R : (R & (~USB_EPnR_DTOG_RX))
+#define SET_DTOG_RX(R)                  (R & USB_EPnR_DTOG_RX) ? (R & (~USB_EPnR_DTOG_RX)) : R
+#define TOGGLE_DTOG_RX(R)               (R | USB_EPnR_DTOG_RX)
+#define KEEP_DTOG_RX(R)                 (R & (~USB_EPnR_DTOG_RX))
+#define CLEAR_DTOG_TX(R)                (R & USB_EPnR_DTOG_TX) ? R : (R & (~USB_EPnR_DTOG_TX))
+#define SET_DTOG_TX(R)                  (R & USB_EPnR_DTOG_TX) ? (R & (~USB_EPnR_DTOG_TX)) : R
+#define TOGGLE_DTOG_TX(R)               (R | USB_EPnR_DTOG_TX)
+#define KEEP_DTOG_TX(R)                 (R & (~USB_EPnR_DTOG_TX))
+#define SET_VALID_RX(R)                 ((R & USB_EPnR_STAT_RX) ^ USB_EPnR_STAT_RX)   | (R & (~USB_EPnR_STAT_RX))
+#define SET_NAK_RX(R)                   ((R & USB_EPnR_STAT_RX) ^ USB_EPnR_STAT_RX_1) | (R & (~USB_EPnR_STAT_RX))
+#define SET_STALL_RX(R)                 ((R & USB_EPnR_STAT_RX) ^ USB_EPnR_STAT_RX_0) | (R & (~USB_EPnR_STAT_RX))
+#define KEEP_STAT_RX(R)                 (R & (~USB_EPnR_STAT_RX))
+#define SET_VALID_TX(R)                 ((R & USB_EPnR_STAT_TX) ^ USB_EPnR_STAT_TX)   | (R & (~USB_EPnR_STAT_TX))
+#define SET_NAK_TX(R)                   ((R & USB_EPnR_STAT_TX) ^ USB_EPnR_STAT_TX_1) | (R & (~USB_EPnR_STAT_TX))
+#define SET_STALL_TX(R)                 ((R & USB_EPnR_STAT_TX) ^ USB_EPnR_STAT_TX_0) | (R & (~USB_EPnR_STAT_TX))
+#define KEEP_STAT_TX(R)                 (R & (~USB_EPnR_STAT_TX))
+#define CLEAR_CTR_RX(R)                 (R & (~USB_EPnR_CTR_RX))
+#define CLEAR_CTR_TX(R)                 (R & (~USB_EPnR_CTR_TX))
+#define CLEAR_CTR_RX_TX(R)              (R & (~(USB_EPnR_CTR_TX | USB_EPnR_CTR_RX)))
+*/
+
+// USB state: uninitialized, addressed, ready for use
+typedef enum{
+    USB_STATE_DEFAULT,
+    USB_STATE_ADDRESSED,
+    USB_STATE_CONFIGURED,
+    USB_STATE_CONNECTED
+} USB_state;
+
+// EP types
+#define EP_TYPE_BULK                    0x00
+#define EP_TYPE_CONTROL                 0x01
+#define EP_TYPE_ISO                     0x02
+#define EP_TYPE_INTERRUPT               0x03
+
+#define LANG_US (uint16_t)0x0409
+
+#define USB_STRING(name, str)                  \
+static const struct name \
+{                          \
+        uint8_t  bLength;                       \
+        uint8_t  bDescriptorType;               \
+        uint16_t bString[(sizeof(str) - 2) / 2]; \
+    \
+} \
+name = {sizeof(name), 0x03, str}
+
+#define USB_LANG_ID(name, lng_id)     \
+    \
+static const struct name \
+{         \
+        uint8_t  bLength;         \
+        uint8_t  bDescriptorType; \
+        uint16_t bString;         \
+    \
+} \
+name = {0x04, 0x03, lng_id}
+#define STRING_LANG_DESCRIPTOR_SIZE_BYTE    (4)
+
+// EP0 configuration packet
+typedef struct {
+    uint8_t bmRequestType;
+    uint8_t bRequest;
+    uint16_t wValue;
+    uint16_t wIndex;
+    uint16_t wLength;
+} config_pack_t;
+
+// endpoints state
+typedef struct __ep_t{
+    uint16_t *tx_buf;           // transmission buffer address
+    uint16_t txbufsz;           // transmission buffer size
+    uint16_t *rx_buf;           // reception buffer address
+    void (*func)();             // endpoint action function
+    unsigned rx_cnt  : 10;      // received data counter
+} ep_t;
+
+// USB status & its address
+typedef struct {
+    uint8_t  USB_Status;
+    uint16_t USB_Addr;
+}usb_dev_t;
+
+typedef struct {
+    uint32_t dwDTERate;
+    uint8_t bCharFormat;
+    #define USB_CDC_1_STOP_BITS   0
+    #define USB_CDC_1_5_STOP_BITS 1
+    #define USB_CDC_2_STOP_BITS   2
+    uint8_t bParityType;
+    #define USB_CDC_NO_PARITY     0
+    #define USB_CDC_ODD_PARITY    1
+    #define USB_CDC_EVEN_PARITY   2
+    #define USB_CDC_MARK_PARITY   3
+    #define USB_CDC_SPACE_PARITY  4
+    uint8_t bDataBits;
+} __attribute__ ((packed)) usb_LineCoding;
+
+typedef struct {
+    uint8_t   bmRequestType;
+    uint8_t   bNotificationType;
+    uint16_t  wValue;
+    uint16_t  wIndex;
+    uint16_t  wLength;
+} __attribute__ ((packed)) usb_cdc_notification;
+
+extern ep_t endpoints[];
+extern usb_dev_t USB_Dev;
+extern uint8_t usbON;
+
+void USB_Init();
+void USB_ResetState();
+int EP_Init(uint8_t number, uint8_t type, uint16_t txsz, uint16_t rxsz, void (*func)());
+void EP_WriteIRQ(uint8_t number, const uint8_t *buf, uint16_t size);
+void EP_Write(uint8_t number, const uint8_t *buf, uint16_t size);
+int EP_Read(uint8_t number, uint16_t *buf);
+usb_LineCoding getLineCoding();
+
+void linecoding_handler(usb_LineCoding *lc);
+void clstate_handler(uint16_t val);
+void break_handler();
+
+#endif // __USB_LIB_H__

F1:F103/DHT22_DHT11/Makefile

@@ -0,0 +1,139 @@
+BINARY		= DHT22
+BOOTPORT	?= /dev/ttyUSB0
+BOOTSPEED	?= 115200
+# MCU FAMILY
+FAMILY		?= F1
+# MCU code
+MCU			?= F103x8
+# density (stm32f10x.h, lines 70-84)
+DENSITY 	?= MD
+# change this linking script depending on particular MCU model,
+LDSCRIPT	?= stm32f103x8.ld
+# debug
+#DEFS		= -DEBUG
+
+INDEPENDENT_HEADERS=
+
+FP_FLAGS	?= -msoft-float -mfloat-abi=soft
+ASM_FLAGS	?= -mthumb -mcpu=cortex-m3 -mfix-cortex-m3-ldrd
+ARCH_FLAGS	= $(ASM_FLAGS) $(FP_FLAGS)
+
+###############################################################################
+# Executables
+#PREFIX		?= arm-none-eabi
+# gcc from arm web site 
+PREFIX		?= /opt/bin/arm-none-eabi
+TOOLCHLIB	?= /opt/arm-none-eabi/lib
+RM			:= rm -f
+RMDIR		:= rmdir
+CC			:= $(PREFIX)-gcc
+# don't replace ld with gcc: the binary size would be much greater!!
+LD			:= $(PREFIX)-ld
+AR			:= $(PREFIX)-ar
+AS			:= $(PREFIX)-as
+SIZE 		:= $(PREFIX)-size
+OBJCOPY		:= $(PREFIX)-objcopy
+OBJDUMP		:= $(PREFIX)-objdump
+GDB			:= $(PREFIX)-gdb
+STFLASH		:= $(shell which st-flash)
+STBOOT		:= $(shell which stm32flash)
+DFUUTIL		:= $(shell which dfu-util)
+
+###############################################################################
+# Source files
+OBJDIR 		= mk
+SRC			:= $(wildcard *.c)
+OBJS		:= $(addprefix $(OBJDIR)/, $(SRC:%.c=%.o))
+STARTUP		= $(OBJDIR)/startup.o
+OBJS 		+= $(STARTUP)
+# dependencies: we need them to recompile files if their headers-dependencies changed
+DEPS		:= $(OBJS:.o=.d)
+
+INC_DIR ?= ../inc
+
+INCLUDE 	:= -I$(INC_DIR)/Fx -I$(INC_DIR)/cm
+LIB_DIR		:= $(INC_DIR)/ld
+
+###############################################################################
+# C flags
+CFLAGS		+= -O2 -g -D__thumb2__=1 -MD
+CFLAGS		+= -Wall -Werror -Wextra -Wshadow 
+CFLAGS		+= -fno-common -ffunction-sections -fdata-sections -fno-stack-protector
+CFLAGS		+=  $(ARCH_FLAGS)
+
+###############################################################################
+# Linker flags
+LDFLAGS		+= -nostartfiles --static -nostdlibs 
+LDFLAGS		+= -L$(LIB_DIR) -L$(TOOLCHLIB)
+LDFLAGS		+= -T$(LDSCRIPT)
+
+###############################################################################
+# Used libraries
+LDLIBS		+=  -lc $(shell $(CC) $(CFLAGS) -print-libgcc-file-name)
+
+DEFS		+= -DSTM32$(FAMILY) -DSTM32$(MCU) -DSTM32F10X_$(DENSITY)
+
+ELF		:= $(OBJDIR)/$(BINARY).elf
+LIST	:= $(OBJDIR)/$(BINARY).list
+BIN		:= $(BINARY).bin
+HEX		:= $(BINARY).hex
+
+all: bin list size
+
+elf: $(ELF)
+bin: $(BIN)
+hex: $(HEX)
+list: $(LIST)
+
+ifneq ($(MAKECMDGOALS),clean)
+-include $(DEPS)
+endif
+
+$(OBJDIR):
+	mkdir $(OBJDIR)
+
+$(STARTUP): $(INC_DIR)/startup/vector.c
+	$(CC) $(CFLAGS) $(DEFS) $(INCLUDE) -o $@ -c $<
+
+$(OBJDIR)/%.o: %.c
+	@echo "  CC      $<"
+	$(CC) $(CFLAGS) $(DEFS) $(INCLUDE) -o $@ -c $<
+
+$(BIN): $(ELF)
+	@echo "  OBJCOPY $(BIN)"
+	$(OBJCOPY) -Obinary $(ELF) $(BIN)
+
+$(HEX): $(ELF)
+	@echo "  OBJCOPY $(HEX)"
+	$(OBJCOPY) -Oihex $(ELF) $(HEX)
+
+$(LIST): $(ELF)
+	@echo "  OBJDUMP $(LIST)"
+	$(OBJDUMP) -S $(ELF) > $(LIST)
+
+$(ELF): $(OBJDIR) $(OBJS)
+	@echo "  LD      $(ELF)"
+	$(LD) $(LDFLAGS) $(OBJS) $(LDLIBS) -o $(ELF)
+
+size: $(ELF)
+	$(SIZE) $(ELF)    
+
+clean:
+	@echo "  CLEAN"
+	$(RM) $(OBJS) $(DEPS) $(ELF) $(HEX) $(LIST)
+	@rmdir $(OBJDIR) 2>/dev/null || true
+
+
+flash: $(BIN)
+	@echo "  FLASH  $(BIN)"
+	$(STFLASH) write $(BIN) 0x8000000
+
+boot: $(BIN)
+	@echo "  LOAD $(BIN) through bootloader"
+	$(STBOOT) -b$(BOOTSPEED) $(BOOTPORT) -w $(BIN)
+
+dfuboot: $(BIN)
+	@echo "  LOAD  $(BIN) THROUGH DFU"
+	$(DFUUTIL) -a0 -D $(BIN) -s 0x08000000
+
+.PHONY: clean flash boot

F1:F103/DHT22_DHT11/Readme

@@ -0,0 +1,2 @@
+Timer1 + DMA to work with DHT22/DHT11 sensors
+#define DHT11 in dht.h to change data format to DHT11

F1:F103/DHT22_DHT11/dht.c

@@ -0,0 +1,210 @@
+/*
+ * This file is part of the DHT22 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "dht.h"
+
+// max amount of bits (including starting)
+#define NmeasurementMax     (45)
+// min length of start pulse
+#define STARTLEN            (150)
+// start pulse max position
+#define STARTMAXPOS         (4)
+// border between zero and one: <border is zero, >border is 1
+#define ZEROBORDER          (100)
+
+//#define EBUG
+
+#ifdef EBUG
+#include "usb.h"
+#include "proto.h"
+#define DBG(x)  do{USB_send(x);}while(0)
+#else
+#define DBG(x)
+#endif
+
+static DHT_state dhtstate = DHT_SLEEP;
+static uint32_t Tstart = 0; // time of start pulse
+uint8_t DHT_tim_overflow = 0;
+static uint8_t CC1array[NmeasurementMax];
+static uint16_t Humidity;
+static int16_t Temperature;
+
+DHT_state DHT_getstate(){return dhtstate;}
+
+void DHT_getdata(uint16_t *Hum, int16_t *T){
+    *Hum = Humidity;
+    *T = Temperature;
+    dhtstate = DHT_SLEEP;
+}
+
+// TIM1_CH1 & TIM1_CH2 are used for total len & zero len pulse measurement
+// T1ch1 - DMA1Ch2
+void DHT_pinsetup(){
+    TIM1->CR1 = 0;
+    RCC->APB2ENR |= RCC_APB2ENR_IOPAEN | RCC_APB2ENR_TIM1EN | RCC_APB2ENR_AFIOEN;
+    RCC->AHBENR |= RCC_AHBENR_DMA1EN;
+    pin_set(GPIOA, 1<<8);
+    // PA8 as opendrain output
+    GPIOA->CRH = (GPIOA->CRH & ~(GPIO_CRH_MODE8 | GPIO_CRH_CNF8)) |
+            CRH(8, CNF_ODOUTPUT | MODE_FAST);
+    TIM1->PSC = 71; // 1MHz
+    TIM1->ARR = 200; // 200mks - max time for measurement
+    // dma->mem, 16bit->8bit,
+    DMA1_Channel2->CCR = DMA_CCR_MINC | DMA_CCR_PSIZE_0 | DMA_CCR_TCIE;
+    DMA1_Channel2->CPAR = (uint32_t)&TIM1->CCR1;
+    DMA1_Channel2->CMAR = (uint32_t)CC1array;
+    NVIC_EnableIRQ(TIM1_UP_IRQn);
+    NVIC_EnableIRQ(DMA1_Channel2_IRQn);
+    dhtstate = DHT_SLEEP;
+}
+
+// start measurement
+static void DHT_startmeas(uint32_t Tms){
+    DBG("DHT_startmeas()\n");
+    pin_set(GPIOA, 1<<8);
+    dhtstate = DHT_MEASURING;
+    Tstart = Tms;
+    // CC1 is input, IC1@TI1, IC2@TI1
+    TIM1->CCMR1 = TIM_CCMR1_CC1S_0 | TIM_CCMR1_CC2S_1;
+    // CC1 active on falling edge, CC2 - on rising, enable capture on both channels
+    TIM1->CCER = TIM_CCER_CC1E | TIM_CCER_CC2E | TIM_CCER_CC1P;
+    // TS=0b101 (trigger input TI1FP1, falling edge), SMS=0b100 (slave mode in reset mode)
+    TIM1->SMCR = TIM_SMCR_TS_2 | TIM_SMCR_TS_0 | TIM_SMCR_SMS_2;
+    // enable update interrupt & DMA events generation
+    TIM1->DIER = TIM_DIER_UIE | TIM_DIER_CC1DE;
+    // prepare DMA
+    DMA1->IFCR = DMA_IFCR_CGIF2; // clear all flags
+    DMA1_Channel2->CNDTR = NmeasurementMax;
+    // enable DMA channel
+    DMA1_Channel2->CCR |= DMA_CCR_EN;
+    // turn it on in, update generation only by overflow
+    TIM1->CR1 = TIM_CR1_CEN | TIM_CR1_URS;
+}
+
+static uint8_t getnext8(int startidx){
+    uint8_t *p = CC1array + startidx;
+    uint8_t x = 0;
+    for(int i = 0; i < 8; ++i){
+        x <<= 1;
+        if(*p++ > ZEROBORDER) x |= 1;
+    }
+    return x;
+}
+
+static void DHT_stopmeas(){
+    DBG("DHT_stopmeas()\n");
+    if(DHT_tim_overflow){
+        DBG("Overflow="); DBG(u2str(DHT_tim_overflow)); DBG("\n");
+    }
+    TIM1->CR1 = 0;
+    TIM1->SMCR = 0;
+    // disnable DMA channel
+    DMA1_Channel2->CCR &= ~DMA_CCR_EN;
+    DHT_tim_overflow = 0;
+    DBG("ctr="); DBG(u2str(DMA1_Channel2->CNDTR)); DBG("\nn\tCC1\n");
+    int nmax = NmeasurementMax - DMA1_Channel2->CNDTR;
+    for(int i = 0; i < nmax; ++i){
+        DBG(u2str(i)); DBG("\t"); DBG(u2str(CC1array[i])); DBG("\n");
+    }
+    dhtstate = DHT_ERROR;
+    // find start pulse
+    int start = -1;
+    for(int i = 0; i < STARTMAXPOS; ++i){
+        if(CC1array[i] > STARTLEN){
+            start = i + 1;
+            break;
+        }
+    }
+    if(start == -1){
+        DBG("No start pulse\n");
+        return;
+    }
+    if(nmax - start < 40){ // no data & start pulse
+        DBG("Insufficient length\n");
+        return;
+    }
+    uint8_t x[5];
+    for(int i = 0; i < 5; ++i, start += 8){
+        x[i] = getnext8(start);
+        DBG(u2str(getnext8(start))); DBG(" ");
+    }
+    uint8_t sum = x[0];
+    for(int i = 1; i < 4; ++i) sum += x[i];
+    if(sum != x[4]){
+        DBG("Checksum failed\n");
+        DBG("sum="); DBG(u2str(sum));
+        DBG(", ch="); DBG(u2str(x[4])); DBG("\n");
+        return;
+    }
+#ifndef DHT11
+    Humidity = (x[0] << 8) | x[1];
+    Temperature = ((x[2]&0x7f) << 8) | x[3];
+#else
+    Humidity = x[0];
+    Temperature = x[2]&0x7f;
+#endif
+    if(x[2] & 0x80) Temperature = -Temperature;
+    dhtstate = DHT_GOTRESULT;
+}
+
+// processing, Tms - current time in milliseconds
+void DHT_process(uint32_t Tms){
+    switch(dhtstate){
+        case DHT_RESETTING:
+            if(Tms - Tstart > DHT_RESETPULSE_LEN) DHT_startmeas(Tms);
+        break;
+        case DHT_MEASURING:
+            if(Tms - Tstart > DHT_MEASUR_LEN || DHT_tim_overflow)
+                DHT_stopmeas();
+        break;
+        default:
+            return;
+    }
+}
+
+/**
+ * @brief DHT_start - start measurement process
+ */
+int DHT_start(uint32_t Tms){
+    if(dhtstate != DHT_SLEEP && dhtstate != DHT_ERROR) return 0;
+    DBG("DHT_start()\n");
+    DHT_tim_overflow = 0;
+    // setup pin into opendrain output mode
+//    GPIOA->CRH = (GPIOA->CRH & ~(GPIO_CRH_MODE8 | GPIO_CRH_CNF8)) |
+//            CRH(8, CNF_ODOUTPUT | MODE_NORMAL);
+    pin_clear(GPIOA, 1<<8);
+    Tstart = Tms;
+    dhtstate = DHT_RESETTING;
+    return 1;
+}
+
+void dma1_channel2_isr(){
+    DMA1->IFCR = DMA_IFCR_CGIF2;
+    TIM1->CR1 = 0;
+    DHT_tim_overflow = 1;
+}
+
+// update IRQ: no data on input
+void tim1_up_isr(){
+    TIM1->SR = 0;
+    TIM1->CR1 = 0;
+    TIM1->DIER = 0;
+    TIM1->SMCR = 0;
+    DHT_tim_overflow = 2;
+}
+

F1:F103/DHT22_DHT11/dht.h

@@ -0,0 +1,48 @@
+/*
+ * This file is part of the DHT22 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+#ifndef DHT_H__
+#define DHT_H__
+
+#include <stm32f1.h>
+
+// define it to work with DHT11
+//#define DHT11
+
+// reset pulse length in ms
+#define DHT_RESETPULSE_LEN      (20)
+// max measurement length
+#define DHT_MEASUR_LEN          (50)
+
+// state of device
+typedef enum{
+    DHT_SLEEP,
+    DHT_RESETTING,
+    DHT_MEASURING,
+    DHT_GOTRESULT,
+    DHT_ERROR
+} DHT_state;
+
+void DHT_pinsetup();
+int DHT_start(uint32_t Tms);
+DHT_state DHT_getstate();
+void DHT_process(uint32_t Tms);
+void DHT_getdata(uint16_t *Hum, int16_t *T);
+
+#endif // DHT_H__
+

F1:F103/DHT22_DHT11/hardware.c

@@ -0,0 +1,48 @@
+/*
+ * This file is part of the DHT22 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "hardware.h"
+
+static inline void gpio_setup(){
+    // Enable clocks to the GPIO subsystems (PB for ADC), turn on AFIO clocking to disable SWD/JTAG
+    RCC->APB2ENR |= RCC_APB2ENR_IOPAEN | RCC_APB2ENR_IOPCEN | RCC_APB2ENR_AFIOEN;
+    // turn off SWJ/JTAG
+//    AFIO->MAPR = AFIO_MAPR_SWJ_CFG_DISABLE;
+    AFIO->MAPR = AFIO_MAPR_SWJ_CFG_JTAGDISABLE; // for PA15
+    // Set led as opendrain output
+    GPIOC->CRH = CRH(13, CNF_ODOUTPUT|MODE_SLOW);
+    // USB pullup (PA15) - pushpull output
+    GPIOA->CRH = CRH(15, CNF_PPOUTPUT|MODE_SLOW);
+}
+
+void hw_setup(){
+    gpio_setup();
+}
+
+void iwdg_setup(){
+    uint32_t tmout = 16000000;
+    RCC->CSR |= RCC_CSR_LSION;
+    while((RCC->CSR & RCC_CSR_LSIRDY) != RCC_CSR_LSIRDY){if(--tmout == 0) break;} /* (2) */
+    IWDG->KR = IWDG_START;
+    IWDG->KR = IWDG_WRITE_ACCESS;
+    IWDG->PR = IWDG_PR_PR_1;
+    IWDG->RLR = 1250;
+    tmout = 16000000;
+    while(IWDG->SR){if(--tmout == 0) break;}
+    IWDG->KR = IWDG_REFRESH;
+}

F1:F103/DHT22_DHT11/hardware.h

@@ -0,0 +1,42 @@
+/*
+ * This file is part of the DHT22 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#ifndef __HARDWARE_H__
+#define __HARDWARE_H__
+
+#include "stm32f1.h"
+
+// LED0 - PC13 (bluepill), blinking each second
+#define LED0_port   GPIOC
+#define LED0_pin    (1<<13)
+
+// USB pullup (not present in bluepill, should be soldered) - PA15
+#define USBPU_port  GPIOA
+#define USBPU_pin   (1<<15)
+#define USBPU_ON()  pin_set(USBPU_port, USBPU_pin)
+#define USBPU_OFF() pin_clear(USBPU_port, USBPU_pin)
+
+#define LED_blink(x)    pin_toggle(x ## _port, x ## _pin)
+#define LED_on(x)       pin_clear(x ## _port, x ## _pin)
+#define LED_off(x)      pin_set(x ## _port, x ## _pin)
+
+void hw_setup();
+void iwdg_setup();
+
+#endif // __HARDWARE_H__

F1:F103/DHT22_DHT11/main.c

@@ -0,0 +1,104 @@
+/*
+ * This file is part of the DHT22 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "dht.h"
+#include "hardware.h"
+#include "proto.h"
+#include "usb.h"
+#include "usb_lib.h"
+
+volatile uint32_t Tms = 0;
+
+/* Called when systick fires */
+void sys_tick_handler(void){
+    ++Tms;
+}
+
+// usb getline
+char *get_USB(){
+    static char tmpbuf[512], *curptr = tmpbuf;
+    static int rest = 511;
+    uint8_t x = USB_receive(curptr);
+    curptr[x] = 0;
+    if(!x) return NULL;
+    if(curptr[x-1] == '\n'){
+        curptr = tmpbuf;
+        rest = 511;
+        return tmpbuf;
+    }
+    curptr += x; rest -= x;
+    if(rest <= 0){ // buffer overflow
+        curptr = tmpbuf;
+        rest = 511;
+    }
+    return NULL;
+}
+
+int main(void){
+    uint32_t lastT = 0;
+    sysreset();
+    StartHSE();
+    hw_setup();
+    SysTick_Config(72000);
+
+    RCC->CSR |= RCC_CSR_RMVF; // remove reset flags
+
+    USBPU_OFF();
+    USB_setup();
+    DHT_pinsetup();
+    iwdg_setup();
+    USBPU_ON();
+
+    uint16_t H;
+    int16_t T;
+    while (1){
+        IWDG->KR = IWDG_REFRESH; // refresh watchdog
+        if(lastT > Tms || Tms - lastT > 499){
+            LED_blink(LED0);
+            lastT = Tms;
+        }
+        DHT_process(Tms);
+        if(DHT_GOTRESULT == DHT_getstate()){
+            DHT_getdata(&H, &T);
+            USB_send("Temperature="); USB_send(i2str(T));
+#ifdef DHT11
+            USB_send(" (degC)\nHumidity=");
+#else
+            USB_send(" (/10degC)\nHumidity=");
+#endif
+            USB_send(u2str(H));
+#ifdef DHT11
+            USB_send(" (%)\n");
+#else
+            USB_send(" (/10%)\n");
+#endif
+        }
+        usb_proc();
+        char *txt, *ans;
+        if((txt = get_USB())){
+            IWDG->KR = IWDG_REFRESH;
+            ans = (char*)parse_cmd(txt);
+            if(ans){
+                uint16_t l = 0; char *p = ans;
+                while(*p++) l++;
+                USB_send(ans);
+            }
+        }
+    }
+    return 0;
+}

F1:F103/DHT22_DHT11/proto.c

@@ -0,0 +1,95 @@
+/*
+ * This file is part of the DHT22 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "dht.h"
+#include "proto.h"
+#include "usb.h"
+
+extern volatile uint32_t Tms;
+
+static const char *helpmesg =
+        "'M' - start measurement\n"
+        "'S' - get DHT state\n"
+        "'R' - software reset\n"
+        "'W' - test watchdog\n"
+;
+
+const char *parse_cmd(const char *buf){
+    if(buf[1] != '\n') return buf;
+    switch(*buf){
+        case 'M':
+            if(DHT_start(Tms)) return "Started\n";
+            else return "Wait a little\n";
+        break;
+        case 'R':
+            USB_send("Soft reset\n");
+            NVIC_SystemReset();
+        break;
+        case 'S':
+            switch(DHT_getstate()){
+                case DHT_SLEEP:
+                    return "Sleeping\n";
+                case DHT_RESETTING:
+                    return "Resetting\n";
+                case DHT_MEASURING:
+                    return "Measuring\n";
+                case DHT_GOTRESULT:
+                    return "Results are ready\n";
+                default:
+                    return "Not found\n";
+            }
+        case 'W':
+            USB_send("Wait for reboot\n");
+            while(1){nop();};
+        break;
+        default: // help
+            return helpmesg;
+        break;
+    }
+    return NULL;
+}
+
+static char *_2str(uint32_t  val, uint8_t minus){
+    static char strbuf[12];
+    char *bufptr = &strbuf[11];
+    *bufptr = 0;
+    if(!val){
+        *(--bufptr) = '0';
+    }else{
+        while(val){
+            *(--bufptr) = val % 10 + '0';
+            val /= 10;
+        }
+    }
+    if(minus) *(--bufptr) = '-';
+    return bufptr;
+}
+
+// return string with number `val`
+char *u2str(uint32_t val){
+    return _2str(val, 0);
+}
+char *i2str(int32_t i){
+    uint8_t minus = 0;
+    uint32_t val;
+    if(i < 0){
+        minus = 1;
+        val = -i;
+    }else val = i;
+    return _2str(val, minus);
+}

F1:F103/DHT22_DHT11/proto.h

@@ -0,0 +1,28 @@
+/*
+ * This file is part of the DHT22 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+#ifndef PROTO_H__
+#define PROTO_H__
+
+#include <stm32f1.h>
+
+const char *parse_cmd(const char *buf);
+char *u2str(uint32_t val);
+char *i2str(int32_t i);
+
+#endif // PROTO_H__

F1:F103/DHT22_DHT11/usb.c

@@ -0,0 +1,162 @@
+/*
+ * This file is part of the DHT22 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "usb.h"
+#include "usb_lib.h"
+
+static volatile uint8_t tx_succesfull = 1;
+static volatile uint8_t rxNE = 0;
+
+// interrupt IN handler (never used?)
+static void EP1_Handler(){
+    uint16_t epstatus = KEEP_DTOG(USB->EPnR[1]);
+    if(RX_FLAG(epstatus)) epstatus = (epstatus & ~USB_EPnR_STAT_TX) ^ USB_EPnR_STAT_RX; // set valid RX
+    else epstatus = epstatus & ~(USB_EPnR_STAT_TX|USB_EPnR_STAT_RX);
+    // clear CTR
+    epstatus = (epstatus & ~(USB_EPnR_CTR_RX|USB_EPnR_CTR_TX));
+    USB->EPnR[1] = epstatus;
+}
+
+// data IN/OUT handlers
+static void transmit_Handler(){ // EP3IN
+    tx_succesfull = 1;
+    uint16_t epstatus = KEEP_DTOG_STAT(USB->EPnR[3]);
+    // clear CTR keep DTOGs & STATs
+    USB->EPnR[3] = (epstatus & ~(USB_EPnR_CTR_TX)); // clear TX ctr
+}
+
+static void receive_Handler(){ // EP2OUT
+    rxNE = 1;
+    uint16_t epstatus = KEEP_DTOG_STAT(USB->EPnR[2]);
+    USB->EPnR[2] = (epstatus & ~(USB_EPnR_CTR_RX)); // clear RX ctr
+}
+
+void USB_setup(){
+    NVIC_DisableIRQ(USB_LP_CAN1_RX0_IRQn);
+    NVIC_DisableIRQ(USB_HP_CAN1_TX_IRQn);
+    RCC->APB1ENR |= RCC_APB1ENR_USBEN;
+    USB->CNTR   = USB_CNTR_FRES; // Force USB Reset
+    for(uint32_t ctr = 0; ctr < 72000; ++ctr) nop(); // wait >1ms
+    //uint32_t ctr = 0;
+    USB->CNTR   = 0;
+    USB->BTABLE = 0;
+    USB->DADDR  = 0;
+    USB->ISTR   = 0;
+    USB->CNTR   = USB_CNTR_RESETM | USB_CNTR_WKUPM; // allow only wakeup & reset interrupts
+    NVIC_EnableIRQ(USB_LP_CAN1_RX0_IRQn);
+}
+
+static int usbwr(const uint8_t *buf, uint16_t l){
+    uint32_t ctra = 1000000;
+    while(--ctra && tx_succesfull == 0){
+        IWDG->KR = IWDG_REFRESH;
+    }
+    tx_succesfull = 0;
+    EP_Write(3, buf, l);
+    ctra = 1000000;
+    while(--ctra && tx_succesfull == 0){
+        IWDG->KR = IWDG_REFRESH;
+    }
+    if(tx_succesfull == 0){usbON = 0; return 1;} // usb is OFF?
+    return 0;
+}
+
+static char usbbuff[USB_TXBUFSZ-1]; // temporary buffer (63 - to prevent need of ZLP)
+static uint8_t buflen = 0; // amount of symbols in usbbuff
+
+// send next up to 63 bytes of data in usbbuff
+static void send_next(){
+    if(!buflen || !tx_succesfull) return;
+    tx_succesfull = 0;
+    EP_Write(3, (uint8_t*)usbbuff, buflen);
+    buflen = 0;
+}
+
+// unblocking sending - just fill a buffer
+void USB_send(const char *buf){
+    if(!usbON) return;
+    uint16_t len = 0;
+    const char *b = buf;
+    while(*b++) ++len;
+    if(len > USB_TXBUFSZ-1 - buflen){
+        usbwr((uint8_t*)usbbuff, buflen);
+        buflen = 0;
+    }
+    if(len > USB_TXBUFSZ-1){
+        USB_send_blk(buf, len);
+        return;
+    }
+    while(len--) usbbuff[buflen++] = *buf++;
+}
+
+// blocking sending
+void USB_send_blk(const char *buf, uint16_t len){
+    if(!usbON || !len) return; // USB disconnected
+    if(buflen){
+        usbwr((uint8_t*)usbbuff, buflen);
+        buflen = 0;
+    }
+    int needzlp = 0;
+    while(len){
+        if(len == USB_TXBUFSZ) needzlp = 1;
+        uint16_t s = (len > USB_TXBUFSZ) ? USB_TXBUFSZ : len;
+        if(usbwr((uint8_t*)buf, s)) return;
+        len -= s;
+        buf += s;
+    }
+    if(needzlp){
+        usbwr(NULL, 0);
+    }
+}
+
+void usb_proc(){
+    switch(USB_Dev.USB_Status){
+        case USB_STATE_CONFIGURED:
+            // make new BULK endpoint
+            // Buffer have 1024 bytes, but last 256 we use for CAN bus (30.2 of RM: USB main features)
+            EP_Init(1, EP_TYPE_INTERRUPT, USB_EP1BUFSZ, 0, EP1_Handler); // IN1 - transmit
+            EP_Init(2, EP_TYPE_BULK, 0, USB_RXBUFSZ, receive_Handler); // OUT2 - receive data
+            EP_Init(3, EP_TYPE_BULK, USB_TXBUFSZ, 0, transmit_Handler); // IN3 - transmit data
+            USB_Dev.USB_Status = USB_STATE_CONNECTED;
+        break;
+        case USB_STATE_DEFAULT:
+        case USB_STATE_ADDRESSED:
+            if(usbON){
+                usbON = 0;
+            }
+        break;
+        default: // USB_STATE_CONNECTED - send next data portion
+            if(!usbON) return;
+            send_next();
+    }
+}
+
+/**
+ * @brief USB_receive
+ * @param buf (i) - buffer[64] for received data
+ * @return amount of received bytes
+ */
+uint8_t USB_receive(char *buf){
+    if(!usbON || !rxNE) return 0;
+    uint8_t sz = EP_Read(2, (uint16_t*)buf);
+    uint16_t epstatus = KEEP_DTOG(USB->EPnR[2]);
+    // keep stat_tx & set ACK rx
+    USB->EPnR[2] = (epstatus & ~(USB_EPnR_STAT_TX)) ^ USB_EPnR_STAT_RX;
+    rxNE = 0;
+    return sz;
+}

F1:F103/DHT22_DHT11/usb.h

@@ -0,0 +1,33 @@
+/*
+ * This file is part of the DHT22 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#ifndef __USB_H__
+#define __USB_H__
+
+#include "hardware.h"
+
+#define BUFFSIZE   (64)
+
+void USB_setup();
+void usb_proc();
+void USB_send(const char *buf);
+void USB_send_blk(const char *buf, uint16_t len);
+uint8_t USB_receive(char *buf);
+
+#endif // __USB_H__

F1:F103/DHT22_DHT11/usb_defs.h

@@ -0,0 +1,102 @@
+/*
+ * This file is part of the DHT22 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#ifndef __USB_DEFS_H__
+#define __USB_DEFS_H__
+
+#include <stm32f1.h>
+
+// max endpoints number
+#define STM32ENDPOINTS          8
+/**
+ *                 Buffers size definition
+ **/
+#define USB_BTABLE_SIZE         512
+// first 64 bytes of USB_BTABLE are registers!
+//#define USB_EP0_BASEADDR        64
+// for USB FS EP0 buffers are from 8 to 64 bytes long (64 for PL2303)
+#define USB_EP0_BUFSZ           64
+// USB transmit buffer size (64 for PL2303)
+#define USB_TXBUFSZ             64
+// USB receive buffer size (64 for PL2303)
+#define USB_RXBUFSZ             64
+// EP1 - interrupt - buffer size
+#define USB_EP1BUFSZ            8
+
+#define USB_BTABLE_BASE         0x40006000
+#define USB_BASE                ((uint32_t)0x40005C00)
+#define USB                     ((USB_TypeDef *) USB_BASE)
+
+#ifdef USB_BTABLE
+#undef USB_BTABLE
+#endif
+#define USB_BTABLE              ((USB_BtableDef *)(USB_BTABLE_BASE))
+#define USB_ISTR_EPID           0x0000000F
+#define USB_FNR_LSOF_0          0x00000800
+#define USB_FNR_lSOF_1          0x00001000
+#define USB_LPMCSR_BESL_0       0x00000010
+#define USB_LPMCSR_BESL_1       0x00000020
+#define USB_LPMCSR_BESL_2       0x00000040
+#define USB_LPMCSR_BESL_3       0x00000080
+#define USB_EPnR_CTR_RX         0x00008000
+#define USB_EPnR_DTOG_RX        0x00004000
+#define USB_EPnR_STAT_RX        0x00003000
+#define USB_EPnR_STAT_RX_0      0x00001000
+#define USB_EPnR_STAT_RX_1      0x00002000
+#define USB_EPnR_SETUP          0x00000800
+#define USB_EPnR_EP_TYPE        0x00000600
+#define USB_EPnR_EP_TYPE_0      0x00000200
+#define USB_EPnR_EP_TYPE_1      0x00000400
+#define USB_EPnR_EP_KIND        0x00000100
+#define USB_EPnR_CTR_TX         0x00000080
+#define USB_EPnR_DTOG_TX        0x00000040
+#define USB_EPnR_STAT_TX        0x00000030
+#define USB_EPnR_STAT_TX_0      0x00000010
+#define USB_EPnR_STAT_TX_1      0x00000020
+#define USB_EPnR_EA             0x0000000F
+#define USB_COUNTn_RX_BLSIZE    0x00008000
+#define USB_COUNTn_NUM_BLOCK    0x00007C00
+#define USB_COUNTn_RX           0x0000003F
+
+#ifdef USB_TypeDef
+#define USB_TypeDef USB_TypeDef_custom
+#endif
+
+typedef struct {
+    __IO uint32_t EPnR[STM32ENDPOINTS];
+    __IO uint32_t RESERVED[STM32ENDPOINTS];
+    __IO uint32_t CNTR;
+    __IO uint32_t ISTR;
+    __IO uint32_t FNR;
+    __IO uint32_t DADDR;
+    __IO uint32_t BTABLE;
+} USB_TypeDef;
+
+typedef struct{
+    __IO uint32_t USB_ADDR_TX;
+    __IO uint32_t USB_COUNT_TX;
+    __IO uint32_t USB_ADDR_RX;
+    __IO uint32_t USB_COUNT_RX;
+} USB_EPDATA_TypeDef;
+
+typedef struct{
+    __IO USB_EPDATA_TypeDef EP[STM32ENDPOINTS];
+} USB_BtableDef;
+
+#endif // __USB_DEFS_H__

F1:F103/DHT22_DHT11/usb_lib.c

@@ -0,0 +1,476 @@
+/*
+ * This file is part of the DHT22 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdint.h>
+#include "usb_lib.h"
+
+ep_t endpoints[STM32ENDPOINTS];
+
+usb_dev_t USB_Dev;
+static usb_LineCoding lineCoding = {115200, 0, 0, 8};
+static config_pack_t setup_packet;
+static uint8_t ep0databuf[EP0DATABUF_SIZE];
+static uint8_t ep0dbuflen = 0;
+
+usb_LineCoding getLineCoding(){return lineCoding;}
+
+uint8_t usbON = 0; // device disconnected from terminal
+
+// definition of parts common for USB_DeviceDescriptor & USB_DeviceQualifierDescriptor
+#define bcdUSB_L        0x10
+#define bcdUSB_H        0x01
+#define bDeviceClass    0
+#define bDeviceSubClass 0
+#define bDeviceProtocol 0
+#define bNumConfigurations 1
+
+static const uint8_t USB_DeviceDescriptor[] = {
+        18,     // bLength
+        0x01,   // bDescriptorType - Device descriptor
+        bcdUSB_L,   // bcdUSB_L - 1.10
+        bcdUSB_H,   // bcdUSB_H
+        bDeviceClass,   // bDeviceClass - USB_COMM
+        bDeviceSubClass,   // bDeviceSubClass
+        bDeviceProtocol,   // bDeviceProtocol
+        USB_EP0_BUFSZ,   // bMaxPacketSize
+        0x7b,   // idVendor_L PL2303: VID=0x067b, PID=0x2303
+        0x06,   // idVendor_H
+        0x03,   // idProduct_L
+        0x23,   // idProduct_H
+        0x00,   // bcdDevice_Ver_L
+        0x03,   // bcdDevice_Ver_H
+        0x01,   // iManufacturer
+        0x02,   // iProduct
+        0x00,   // iSerialNumber
+        bNumConfigurations    // bNumConfigurations
+};
+
+static const uint8_t USB_DeviceQualifierDescriptor[] = {
+        10,     //bLength
+        0x06,   // bDescriptorType - Device qualifier
+        bcdUSB_L,   // bcdUSB_L
+        bcdUSB_H,   // bcdUSB_H
+        bDeviceClass,   // bDeviceClass
+        bDeviceSubClass,   // bDeviceSubClass
+        bDeviceProtocol,   // bDeviceProtocol
+        USB_EP0_BUFSZ,   // bMaxPacketSize0
+        bNumConfigurations,   // bNumConfigurations
+        0x00    // Reserved
+};
+
+static const uint8_t USB_ConfigDescriptor[] = {
+        /*Configuration Descriptor*/
+        0x09, /* bLength: Configuration Descriptor size */
+        0x02, /* bDescriptorType: Configuration */
+        39,   /* wTotalLength:no of returned bytes */
+        0x00,
+        0x01, /* bNumInterfaces: 1 interface */
+        0x01, /* bConfigurationValue: Configuration value */
+        0x00, /* iConfiguration: Index of string descriptor describing the configuration */
+        0xa0, /* bmAttributes - Bus powered, Remote wakeup */
+        0x32, /* MaxPower 100 mA */
+
+        /*---------------------------------------------------------------------------*/
+
+        /*Interface Descriptor */
+        0x09, /* bLength: Interface Descriptor size */
+        0x04, /* bDescriptorType: Interface */
+        0x00, /* bInterfaceNumber: Number of Interface */
+        0x00, /* bAlternateSetting: Alternate setting */
+        0x03, /* bNumEndpoints: 3 endpoints used */
+        0xff, /* bInterfaceClass */
+        0x00, /* bInterfaceSubClass */
+        0x00, /* bInterfaceProtocol */
+        0x00, /* iInterface: */
+///////////////////////////////////////////////////
+        /*Endpoint 1 Descriptor*/
+        0x07, /* bLength: Endpoint Descriptor size */
+        0x05, /* bDescriptorType: Endpoint */
+        0x81, /* bEndpointAddress IN1 */
+        0x03, /* bmAttributes: Interrupt */
+        0x0a, /* wMaxPacketSize LO: */
+        0x00, /* wMaxPacketSize HI: */
+        0x01, /* bInterval: */
+
+        /*Endpoint OUT2 Descriptor*/
+        0x07, /* bLength: Endpoint Descriptor size */
+        0x05, /* bDescriptorType: Endpoint */
+        0x02, /* bEndpointAddress: OUT2 */
+        0x02, /* bmAttributes: Bulk */
+        (USB_RXBUFSZ & 0xff), /* wMaxPacketSize: 64 */
+        (USB_RXBUFSZ >> 8),
+        0x00, /* bInterval: ignore for Bulk transfer */
+
+        /*Endpoint IN3 Descriptor*/
+        0x07, /* bLength: Endpoint Descriptor size */
+        0x05, /* bDescriptorType: Endpoint */
+        0x83, /* bEndpointAddress IN3 */
+        0x02, /* bmAttributes: Bulk */
+        (USB_TXBUFSZ & 0xff), /* wMaxPacketSize: 64 */
+        (USB_TXBUFSZ >> 8),
+        0x00, /* bInterval: ignore for Bulk transfer */
+};
+
+_USB_LANG_ID_(USB_StringLangDescriptor, LANG_US);
+// these descriptors are not used in PL2303 emulator!
+_USB_STRING_(USB_StringSerialDescriptor, u"0");
+_USB_STRING_(USB_StringManufacturingDescriptor, u"Prolific Technology Inc.");
+_USB_STRING_(USB_StringProdDescriptor, u"USB-Serial Controller");
+
+/*
+ * default handlers
+ */
+// SET_LINE_CODING
+void WEAK linecoding_handler(usb_LineCoding __attribute__((unused)) *lc){
+}
+
+// SET_CONTROL_LINE_STATE
+void WEAK clstate_handler(uint16_t __attribute__((unused)) val){
+}
+
+// SEND_BREAK
+void WEAK break_handler(){
+}
+
+// handler of vendor requests
+void WEAK vendor_handler(config_pack_t *packet){
+    if(packet->bmRequestType & 0x80){ // read
+        uint8_t c;
+        switch(packet->wValue){
+            case 0x8484:
+                c = 2;
+            break;
+            case 0x0080:
+                c = 1;
+            break;
+            case 0x8686:
+                c = 0xaa;
+            break;
+            default:
+                c = 0;
+        }
+        EP_WriteIRQ(0, &c, 1);
+    }else{ // write ZLP
+        EP_WriteIRQ(0, (uint8_t *)0, 0);
+    }
+}
+
+static void wr0(const uint8_t *buf, uint16_t size){
+    if(setup_packet.wLength < size) size = setup_packet.wLength; // shortened request
+    if(size < endpoints[0].txbufsz){
+        EP_WriteIRQ(0, buf, size);
+        return;
+    }
+    while(size){
+        uint16_t l = size;
+        if(l > endpoints[0].txbufsz) l = endpoints[0].txbufsz;
+        EP_WriteIRQ(0, buf, l);
+        buf += l;
+        size -= l;
+        uint8_t needzlp = (l == endpoints[0].txbufsz) ? 1 : 0;
+        if(size || needzlp){ // send last data buffer
+            uint16_t status = KEEP_DTOG(USB->EPnR[0]);
+            // keep DTOGs, clear CTR_RX,TX, set TX VALID, leave stat_Rx
+            USB->EPnR[0] = (status & ~(USB_EPnR_CTR_RX|USB_EPnR_CTR_TX|USB_EPnR_STAT_RX))
+                            ^ USB_EPnR_STAT_TX;
+            uint32_t ctr = 1000000;
+            while(--ctr && (USB->ISTR & USB_ISTR_CTR) == 0){IWDG->KR = IWDG_REFRESH;};
+            if((USB->ISTR & USB_ISTR_CTR) == 0){
+                return;
+            }
+            if(needzlp) EP_WriteIRQ(0, (uint8_t*)0, 0);
+        }
+    }
+}
+
+static inline void get_descriptor(){
+    switch(setup_packet.wValue){
+        case DEVICE_DESCRIPTOR:
+            wr0(USB_DeviceDescriptor, sizeof(USB_DeviceDescriptor));
+        break;
+        case CONFIGURATION_DESCRIPTOR:
+            wr0(USB_ConfigDescriptor, sizeof(USB_ConfigDescriptor));
+        break;
+        case STRING_LANG_DESCRIPTOR:
+            wr0((const uint8_t *)&USB_StringLangDescriptor, STRING_LANG_DESCRIPTOR_SIZE_BYTE);
+        break;
+        case STRING_MAN_DESCRIPTOR:
+            wr0((const uint8_t *)&USB_StringManufacturingDescriptor, USB_StringManufacturingDescriptor.bLength);
+        break;
+        case STRING_PROD_DESCRIPTOR:
+            wr0((const uint8_t *)&USB_StringProdDescriptor, USB_StringProdDescriptor.bLength);
+        break;
+        case STRING_SN_DESCRIPTOR:
+            wr0((const uint8_t *)&USB_StringSerialDescriptor, USB_StringSerialDescriptor.bLength);
+        break;
+        case DEVICE_QUALIFIER_DESCRIPTOR:
+            wr0(USB_DeviceQualifierDescriptor, USB_DeviceQualifierDescriptor[0]);
+        break;
+        default:
+        break;
+    }
+}
+
+static uint8_t configuration = 0; // reply for GET_CONFIGURATION (==1 if configured)
+static inline void std_d2h_req(){
+    uint16_t status = 0; // bus powered
+    switch(setup_packet.bRequest){
+        case GET_DESCRIPTOR:
+            get_descriptor();
+        break;
+        case GET_STATUS:
+            EP_WriteIRQ(0, (uint8_t *)&status, 2); // send status: Bus Powered
+        break;
+        case GET_CONFIGURATION:
+            EP_WriteIRQ(0, &configuration, 1);
+        break;
+        default:
+        break;
+    }
+}
+
+static inline void std_h2d_req(){
+    switch(setup_packet.bRequest){
+        case SET_ADDRESS:
+            // new address will be assigned later - after  acknowlegement or request to host
+            USB_Dev.USB_Addr = setup_packet.wValue;
+        break;
+        case SET_CONFIGURATION:
+            // Now device configured
+            USB_Dev.USB_Status = USB_STATE_CONFIGURED;
+            configuration = setup_packet.wValue;
+        break;
+        default:
+        break;
+    }
+}
+
+/*
+bmRequestType: 76543210
+7    direction: 0 - host->device, 1 - device->host
+65   type: 0 - standard, 1 - class, 2 - vendor
+4..0 getter: 0 - device, 1 - interface, 2 - endpoint, 3 - other
+*/
+/**
+ * Endpoint0 (control) handler
+ */
+static void EP0_Handler(){
+    uint16_t epstatus = USB->EPnR[0]; // EP0R on input -> return this value after modifications
+    uint8_t reqtype = setup_packet.bmRequestType & 0x7f;
+    uint8_t dev2host = (setup_packet.bmRequestType & 0x80) ? 1 : 0;
+    int rxflag = RX_FLAG(epstatus);
+    if(rxflag && SETUP_FLAG(epstatus)){
+        switch(reqtype){
+            case STANDARD_DEVICE_REQUEST_TYPE: // standard device request
+                if(dev2host){
+                    std_d2h_req();
+                }else{
+                    std_h2d_req();
+                    EP_WriteIRQ(0, (uint8_t *)0, 0);
+                }
+            break;
+            case STANDARD_ENDPOINT_REQUEST_TYPE: // standard endpoint request
+                if(setup_packet.bRequest == CLEAR_FEATURE){
+                    EP_WriteIRQ(0, (uint8_t *)0, 0);
+                }
+            break;
+            case VENDOR_REQUEST_TYPE:
+                vendor_handler(&setup_packet);
+            break;
+            case CONTROL_REQUEST_TYPE:
+                switch(setup_packet.bRequest){
+                    case GET_LINE_CODING:
+                        EP_WriteIRQ(0, (uint8_t*)&lineCoding, sizeof(lineCoding));
+                    break;
+                    case SET_LINE_CODING: // omit this for next stage, when data will come
+                    break;
+                    case SET_CONTROL_LINE_STATE:
+                        usbON = 1;
+                        clstate_handler(setup_packet.wValue);
+                    break;
+                    case SEND_BREAK:
+                        usbON = 0;
+                        break_handler();
+                    break;
+                    default:
+                    break;
+                }
+                if(setup_packet.bRequest != GET_LINE_CODING) EP_WriteIRQ(0, (uint8_t *)0, 0); // write acknowledgement
+            break;
+            default:
+                EP_WriteIRQ(0, (uint8_t *)0, 0);
+        }
+    }else if(rxflag){ // got data over EP0 or host acknowlegement
+        if(endpoints[0].rx_cnt){
+            if(setup_packet.bRequest == SET_LINE_CODING){
+                linecoding_handler((usb_LineCoding*)ep0databuf);
+            }
+        }
+    } else if(TX_FLAG(epstatus)){ // package transmitted
+        // now we can change address after enumeration
+        if ((USB->DADDR & USB_DADDR_ADD) != USB_Dev.USB_Addr){
+            USB->DADDR = USB_DADDR_EF | USB_Dev.USB_Addr;
+            // change state to ADRESSED
+            USB_Dev.USB_Status = USB_STATE_ADDRESSED;
+        }
+    }
+    epstatus = KEEP_DTOG(USB->EPnR[0]);
+    if(rxflag) epstatus ^= USB_EPnR_STAT_TX; // start ZLP/data transmission
+    else epstatus &= ~USB_EPnR_STAT_TX; // or leave unchanged
+    // keep DTOGs, clear CTR_RX,TX, set RX VALID
+    USB->EPnR[0] = (epstatus & ~(USB_EPnR_CTR_RX|USB_EPnR_CTR_TX)) ^ USB_EPnR_STAT_RX;
+}
+
+static uint16_t lastaddr = LASTADDR_DEFAULT;
+/**
+ * Endpoint initialisation
+ * @param number - EP num (0...7)
+ * @param type - EP type (EP_TYPE_BULK, EP_TYPE_CONTROL, EP_TYPE_ISO, EP_TYPE_INTERRUPT)
+ * @param txsz - transmission buffer size @ USB/CAN buffer
+ * @param rxsz - reception buffer size @ USB/CAN buffer
+ * @param uint16_t (*func)(ep_t *ep) - EP handler function
+ * @return 0 if all OK
+ */
+int EP_Init(uint8_t number, uint8_t type, uint16_t txsz, uint16_t rxsz, void (*func)(ep_t ep)){
+    if(number >= STM32ENDPOINTS) return 4; // out of configured amount
+    if(txsz > USB_BTABLE_SIZE || rxsz > USB_BTABLE_SIZE) return 1; // buffer too large
+    if(lastaddr + txsz + rxsz >= USB_BTABLE_SIZE) return 2; // out of btable
+    USB->EPnR[number] = (type << 9) | (number & USB_EPnR_EA);
+    USB->EPnR[number] ^= USB_EPnR_STAT_RX | USB_EPnR_STAT_TX_1;
+    if(rxsz & 1 || rxsz > 512) return 3; // wrong rx buffer size
+    uint16_t countrx = 0;
+    if(rxsz < 64) countrx = rxsz / 2;
+    else{
+        if(rxsz & 0x1f) return 3; // should be multiple of 32
+        countrx = 31 + rxsz / 32;
+    }
+    USB_BTABLE->EP[number].USB_ADDR_TX = lastaddr;
+    endpoints[number].tx_buf = (uint16_t *)(USB_BTABLE_BASE + lastaddr*2);
+    endpoints[number].txbufsz = txsz;
+    lastaddr += txsz;
+    USB_BTABLE->EP[number].USB_COUNT_TX = 0;
+    USB_BTABLE->EP[number].USB_ADDR_RX = lastaddr;
+    endpoints[number].rx_buf = (uint16_t *)(USB_BTABLE_BASE + lastaddr*2);
+    lastaddr += rxsz;
+    USB_BTABLE->EP[number].USB_COUNT_RX = countrx << 10;
+    endpoints[number].func = func;
+    return 0;
+}
+
+// standard IRQ handler
+void usb_lp_can_rx0_isr(){
+    if(USB->ISTR & USB_ISTR_RESET){
+        usbON = 0;
+        // Reinit registers
+        USB->CNTR = USB_CNTR_RESETM | USB_CNTR_CTRM | USB_CNTR_SUSPM | USB_CNTR_WKUPM;
+        USB->ISTR = 0;
+        // Endpoint 0 - CONTROL
+        // ON USB LS size of EP0 may be 8 bytes, but on FS it should be 64 bytes!
+        lastaddr = LASTADDR_DEFAULT;
+        // clear address, leave only enable bit
+        USB->DADDR = USB_DADDR_EF;
+        USB_Dev.USB_Status = USB_STATE_DEFAULT;
+        USB->ISTR = ~USB_ISTR_RESET;
+        if(EP_Init(0, EP_TYPE_CONTROL, USB_EP0_BUFSZ, USB_EP0_BUFSZ, EP0_Handler)){
+            return;
+        }
+    }
+    if(USB->ISTR & USB_ISTR_CTR){
+        // EP number
+        uint8_t n = USB->ISTR & USB_ISTR_EPID;
+        // copy status register
+        uint16_t epstatus = USB->EPnR[n];
+        // copy received bytes amount
+        endpoints[n].rx_cnt = USB_BTABLE->EP[n].USB_COUNT_RX & 0x3FF; // low 10 bits is counter
+        // check direction
+        if(USB->ISTR & USB_ISTR_DIR){ // OUT interrupt - receive data, CTR_RX==1 (if CTR_TX == 1 - two pending transactions: receive following by transmit)
+            if(n == 0){ // control endpoint
+                if(epstatus & USB_EPnR_SETUP){ // setup packet -> copy data to conf_pack
+                    EP_Read(0, (uint16_t*)&setup_packet);
+                    ep0dbuflen = 0;
+                    // interrupt handler will be called later
+                }else if(epstatus & USB_EPnR_CTR_RX){ // data packet -> push received data to ep0databuf
+                    ep0dbuflen = endpoints[0].rx_cnt;
+                    EP_Read(0, (uint16_t*)&ep0databuf);
+                }
+            }
+        }
+        // call EP handler
+        if(endpoints[n].func) endpoints[n].func(endpoints[n]);
+    }
+    if(USB->ISTR & USB_ISTR_SUSP){ // suspend -> still no connection, may sleep
+        usbON = 0;
+        USB->CNTR |= USB_CNTR_FSUSP | USB_CNTR_LP_MODE;
+        USB->ISTR = ~USB_ISTR_SUSP;
+    }
+    if(USB->ISTR & USB_ISTR_WKUP){ // wakeup
+        USB->CNTR &= ~(USB_CNTR_FSUSP | USB_CNTR_LP_MODE); // clear suspend flags
+        USB->ISTR = ~USB_ISTR_WKUP;
+    }
+}
+
+/**
+ * Write data to EP buffer (called from IRQ handler)
+ * @param number - EP number
+ * @param *buf - array with data
+ * @param size - its size
+ */
+void EP_WriteIRQ(uint8_t number, const uint8_t *buf, uint16_t size){
+    uint8_t i;
+    if(size > endpoints[number].txbufsz) size = endpoints[number].txbufsz;
+    uint16_t N2 = (size + 1) >> 1;
+    // the buffer is 16-bit, so we should copy data as it would be uint16_t
+    uint16_t *buf16 = (uint16_t *)buf;
+    uint32_t *out = (uint32_t *)endpoints[number].tx_buf;
+    for(i = 0; i < N2; ++i, ++out){
+        *out = buf16[i];
+    }
+    USB_BTABLE->EP[number].USB_COUNT_TX = size;
+}
+
+/**
+ * Write data to EP buffer (called outside IRQ handler)
+ * @param number - EP number
+ * @param *buf - array with data
+ * @param size - its size
+ */
+void EP_Write(uint8_t number, const uint8_t *buf, uint16_t size){
+    EP_WriteIRQ(number, buf, size);
+    uint16_t status = KEEP_DTOG(USB->EPnR[number]);
+    // keep DTOGs, clear CTR_TX & set TX VALID to start transmission
+    USB->EPnR[number] = (status & ~(USB_EPnR_CTR_TX)) ^ USB_EPnR_STAT_TX;
+}
+
+/*
+ * Copy data from EP buffer into user buffer area
+ * @param *buf - user array for data
+ * @return amount of data read
+ */
+int EP_Read(uint8_t number, uint16_t *buf){
+    int sz = endpoints[number].rx_cnt;
+    if(!sz) return 0;
+    endpoints[number].rx_cnt = 0;
+    int n = (sz + 1) >> 1;
+    uint32_t *in = (uint32_t *)endpoints[number].rx_buf;
+    if(n){
+        for(int i = 0; i < n; ++i, ++in)
+            buf[i] = *(uint16_t*)in;
+    }
+    return sz;
+}
+

F1:F103/DHT22_DHT11/usb_lib.h

@@ -0,0 +1,184 @@
+/*
+ * This file is part of the DHT22 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#ifndef __USB_LIB_H__
+#define __USB_LIB_H__
+
+#include <wchar.h>
+#include "usb_defs.h"
+
+#define EP0DATABUF_SIZE                 (64)
+#define LASTADDR_DEFAULT                (STM32ENDPOINTS * 8)
+
+// bmRequestType & 0x7f
+#define STANDARD_DEVICE_REQUEST_TYPE    0
+#define STANDARD_ENDPOINT_REQUEST_TYPE  2
+#define VENDOR_REQUEST_TYPE             0x40
+#define CONTROL_REQUEST_TYPE            0x21
+// bRequest, standard; for bmRequestType == 0x80
+#define GET_STATUS                      0x00
+#define GET_DESCRIPTOR                  0x06
+#define GET_CONFIGURATION               0x08
+// for bmRequestType == 0
+#define CLEAR_FEATURE                   0x01
+#define SET_FEATURE                     0x03    // unused
+#define SET_ADDRESS                     0x05
+#define SET_DESCRIPTOR                  0x07    // unused
+#define SET_CONFIGURATION               0x09
+// for bmRequestType == 0x81, 1 or 0xB2
+#define GET_INTERFACE                   0x0A    // unused
+#define SET_INTERFACE                   0x0B    // unused
+#define SYNC_FRAME                      0x0C    // unused
+#define VENDOR_REQUEST                  0x01    // unused
+
+// Class-Specific Control Requests
+#define SEND_ENCAPSULATED_COMMAND       0x00    // unused
+#define GET_ENCAPSULATED_RESPONSE       0x01    // unused
+#define SET_COMM_FEATURE                0x02    // unused
+#define GET_COMM_FEATURE                0x03    // unused
+#define CLEAR_COMM_FEATURE              0x04    // unused
+#define SET_LINE_CODING                 0x20
+#define GET_LINE_CODING                 0x21
+#define SET_CONTROL_LINE_STATE          0x22
+#define SEND_BREAK                      0x23
+
+// control line states
+#define CONTROL_DTR                     0x01
+#define CONTROL_RTS                     0x02
+
+// wValue
+#define DEVICE_DESCRIPTOR               0x100
+#define CONFIGURATION_DESCRIPTOR        0x200
+#define STRING_LANG_DESCRIPTOR          0x300
+#define STRING_MAN_DESCRIPTOR           0x301
+#define STRING_PROD_DESCRIPTOR          0x302
+#define STRING_SN_DESCRIPTOR            0x303
+#define DEVICE_QUALIFIER_DESCRIPTOR     0x600
+
+#define RX_FLAG(epstat)                 (epstat & USB_EPnR_CTR_RX)
+#define TX_FLAG(epstat)                 (epstat & USB_EPnR_CTR_TX)
+#define SETUP_FLAG(epstat)              (epstat & USB_EPnR_SETUP)
+
+// EPnR bits manipulation
+#define KEEP_DTOG_STAT(EPnR)            (EPnR & ~(USB_EPnR_STAT_RX|USB_EPnR_STAT_TX|USB_EPnR_DTOG_RX|USB_EPnR_DTOG_TX))
+#define KEEP_DTOG(EPnR)                 (EPnR & ~(USB_EPnR_DTOG_RX|USB_EPnR_DTOG_TX))
+
+// USB state: uninitialized, addressed, ready for use
+typedef enum{
+    USB_STATE_DEFAULT,
+    USB_STATE_ADDRESSED,
+    USB_STATE_CONFIGURED,
+    USB_STATE_CONNECTED
+} USB_state;
+
+// EP types
+#define EP_TYPE_BULK                    0x00
+#define EP_TYPE_CONTROL                 0x01
+#define EP_TYPE_ISO                     0x02
+#define EP_TYPE_INTERRUPT               0x03
+
+#define LANG_US (uint16_t)0x0409
+
+#define _USB_STRING_(name, str)                  \
+static const struct name \
+{                          \
+        uint8_t  bLength;                       \
+        uint8_t  bDescriptorType;               \
+        uint16_t bString[(sizeof(str) - 2) / 2]; \
+    \
+} \
+name = {sizeof(name), 0x03, str}
+
+#define _USB_LANG_ID_(name, lng_id)     \
+    \
+static const struct name \
+{         \
+        uint8_t  bLength;         \
+        uint8_t  bDescriptorType; \
+        uint16_t bString;         \
+    \
+} \
+name = {0x04, 0x03, lng_id}
+#define STRING_LANG_DESCRIPTOR_SIZE_BYTE    (4)
+
+// EP0 configuration packet
+typedef struct {
+    uint8_t bmRequestType;
+    uint8_t bRequest;
+    uint16_t wValue;
+    uint16_t wIndex;
+    uint16_t wLength;
+} config_pack_t;
+
+// endpoints state
+typedef struct{
+    uint16_t *tx_buf;           // transmission buffer address
+    uint16_t txbufsz;           // transmission buffer size
+    uint16_t *rx_buf;           // reception buffer address
+    void (*func)();             // endpoint action function
+    unsigned rx_cnt  : 10;      // received data counter
+} ep_t;
+
+// USB status & its address
+typedef struct {
+    uint8_t  USB_Status;
+    uint16_t USB_Addr;
+}usb_dev_t;
+
+typedef struct {
+    uint32_t dwDTERate;
+    uint8_t bCharFormat;
+    #define USB_CDC_1_STOP_BITS   0
+    #define USB_CDC_1_5_STOP_BITS 1
+    #define USB_CDC_2_STOP_BITS   2
+    uint8_t bParityType;
+    #define USB_CDC_NO_PARITY     0
+    #define USB_CDC_ODD_PARITY    1
+    #define USB_CDC_EVEN_PARITY   2
+    #define USB_CDC_MARK_PARITY   3
+    #define USB_CDC_SPACE_PARITY  4
+    uint8_t bDataBits;
+} __attribute__ ((packed)) usb_LineCoding;
+
+typedef struct {
+    uint8_t   bmRequestType;
+    uint8_t   bNotificationType;
+    uint16_t  wValue;
+    uint16_t  wIndex;
+    uint16_t  wLength;
+} __attribute__ ((packed)) usb_cdc_notification;
+
+extern ep_t endpoints[];
+extern usb_dev_t USB_Dev;
+extern uint8_t usbON;
+
+void USB_Init();
+void USB_ResetState();
+int EP_Init(uint8_t number, uint8_t type, uint16_t txsz, uint16_t rxsz, void (*func)());
+void EP_WriteIRQ(uint8_t number, const uint8_t *buf, uint16_t size);
+void EP_Write(uint8_t number, const uint8_t *buf, uint16_t size);
+int EP_Read(uint8_t number, uint16_t *buf);
+usb_LineCoding getLineCoding();
+
+void linecoding_handler(usb_LineCoding *lc);
+void clstate_handler(uint16_t val);
+void break_handler();
+void vendor_handler(config_pack_t *packet);
+
+#endif // __USB_LIB_H__

F1:F103/DS18/Makefile

@@ -0,0 +1,139 @@
+BINARY		= DS18
+BOOTPORT	?= /dev/ttyUSB0
+BOOTSPEED	?= 115200
+# MCU FAMILY
+FAMILY		?= F1
+# MCU code
+MCU			?= F103x8
+# density (stm32f10x.h, lines 70-84)
+DENSITY 	?= MD
+# change this linking script depending on particular MCU model,
+LDSCRIPT	?= stm32f103x8.ld
+# debug
+#DEFS		= -DEBUG
+
+INDEPENDENT_HEADERS=
+
+FP_FLAGS	?= -msoft-float -mfloat-abi=soft
+ASM_FLAGS	?= -mthumb -mcpu=cortex-m3 -mfix-cortex-m3-ldrd
+ARCH_FLAGS	= $(ASM_FLAGS) $(FP_FLAGS)
+
+###############################################################################
+# Executables
+#PREFIX		?= arm-none-eabi
+# gcc from arm web site 
+PREFIX		?= /opt/bin/arm-none-eabi
+TOOLCHLIB	?= /opt/arm-none-eabi/lib
+RM			:= rm -f
+RMDIR		:= rmdir
+CC			:= $(PREFIX)-gcc
+# don't replace ld with gcc: the binary size would be much greater!!
+LD			:= $(PREFIX)-ld
+AR			:= $(PREFIX)-ar
+AS			:= $(PREFIX)-as
+SIZE 		:= $(PREFIX)-size
+OBJCOPY		:= $(PREFIX)-objcopy
+OBJDUMP		:= $(PREFIX)-objdump
+GDB			:= $(PREFIX)-gdb
+STFLASH		:= $(shell which st-flash)
+STBOOT		:= $(shell which stm32flash)
+DFUUTIL		:= $(shell which dfu-util)
+
+###############################################################################
+# Source files
+OBJDIR 		= mk
+SRC			:= $(wildcard *.c)
+OBJS		:= $(addprefix $(OBJDIR)/, $(SRC:%.c=%.o))
+STARTUP		= $(OBJDIR)/startup.o
+OBJS 		+= $(STARTUP)
+# dependencies: we need them to recompile files if their headers-dependencies changed
+DEPS		:= $(OBJS:.o=.d)
+
+INC_DIR ?= ../inc
+
+INCLUDE 	:= -I$(INC_DIR)/Fx -I$(INC_DIR)/cm
+LIB_DIR		:= $(INC_DIR)/ld
+
+###############################################################################
+# C flags
+CFLAGS		+= -O2 -g -D__thumb2__=1 -MD
+CFLAGS		+= -Wall -Werror -Wextra -Wshadow 
+CFLAGS		+= -fno-common -ffunction-sections -fdata-sections -fno-stack-protector
+CFLAGS		+=  $(ARCH_FLAGS)
+
+###############################################################################
+# Linker flags
+LDFLAGS		+= -nostartfiles --static -nostdlibs 
+LDFLAGS		+= -L$(LIB_DIR) -L$(TOOLCHLIB)
+LDFLAGS		+= -T$(LDSCRIPT)
+
+###############################################################################
+# Used libraries
+LDLIBS		+=  -lc $(shell $(CC) $(CFLAGS) -print-libgcc-file-name)
+
+DEFS		+= -DSTM32$(FAMILY) -DSTM32$(MCU) -DSTM32F10X_$(DENSITY)
+
+ELF		:= $(OBJDIR)/$(BINARY).elf
+LIST	:= $(OBJDIR)/$(BINARY).list
+BIN		:= $(BINARY).bin
+HEX		:= $(BINARY).hex
+
+all: bin list size
+
+elf: $(ELF)
+bin: $(BIN)
+hex: $(HEX)
+list: $(LIST)
+
+ifneq ($(MAKECMDGOALS),clean)
+-include $(DEPS)
+endif
+
+$(OBJDIR):
+	mkdir $(OBJDIR)
+
+$(STARTUP): $(INC_DIR)/startup/vector.c
+	$(CC) $(CFLAGS) $(DEFS) $(INCLUDE) -o $@ -c $<
+
+$(OBJDIR)/%.o: %.c
+	@echo "  CC      $<"
+	$(CC) $(CFLAGS) $(DEFS) $(INCLUDE) -o $@ -c $<
+
+$(BIN): $(ELF)
+	@echo "  OBJCOPY $(BIN)"
+	$(OBJCOPY) -Obinary $(ELF) $(BIN)
+
+$(HEX): $(ELF)
+	@echo "  OBJCOPY $(HEX)"
+	$(OBJCOPY) -Oihex $(ELF) $(HEX)
+
+$(LIST): $(ELF)
+	@echo "  OBJDUMP $(LIST)"
+	$(OBJDUMP) -S $(ELF) > $(LIST)
+
+$(ELF): $(OBJDIR) $(OBJS)
+	@echo "  LD      $(ELF)"
+	$(LD) $(LDFLAGS) $(OBJS) $(LDLIBS) -o $(ELF)
+
+size: $(ELF)
+	$(SIZE) $(ELF)    
+
+clean:
+	@echo "  CLEAN"
+	$(RM) $(OBJS) $(DEPS) $(ELF) $(HEX) $(LIST)
+	@rmdir $(OBJDIR) 2>/dev/null || true
+
+
+flash: $(BIN)
+	@echo "  FLASH  $(BIN)"
+	$(STFLASH) write $(BIN) 0x8000000
+
+boot: $(BIN)
+	@echo "  LOAD $(BIN) through bootloader"
+	$(STBOOT) -b$(BOOTSPEED) $(BOOTPORT) -w $(BIN)
+
+dfuboot: $(BIN)
+	@echo "  LOAD  $(BIN) THROUGH DFU"
+	$(DFUUTIL) -a0 -D $(BIN) -s 0x08000000
+
+.PHONY: clean flash boot

F1:F103/DS18/Readme

@@ -0,0 +1,2 @@
+Timer1 + DMA to work with DS18/DHT11 sensors
+#define DHT11 in dht.h to change data format to DHT11

F1:F103/DS18/ds18.c

@@ -0,0 +1,496 @@
+/*
+ * This file is part of the DS18 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "ds18.h"
+#include "proto.h"
+#include "usb.h"
+
+//#define EBUG
+// ID1: 0x28 0xba 0xc7 0xea 0x05 0x00 0x00 0xc2
+// ID2: 0x28 0x68 0xc9 0xe9 0x05 0x00 0x00 0x42
+// ID3: 0x28 0x23 0xef 0xe9 0x05 0x00 0x00 0xab
+
+
+#ifdef EBUG
+#define DBG(x)  do{USB_send(x);}while(0)
+#else
+#define DBG(x)
+#endif
+
+/* TIMING */
+// freq = 1MHz
+// ARR values: 1000 for reset, 100 for data in/out
+// CCR1 values: 500 for reset, 60 for sending 0 or reading, <15 for sending 1
+// CCR2 values: >550 if there's devices on line (on reset), >12 (typ.15) - read 0, < 12 (typ.1) - read 1
+#define RESET_LEN         ((uint16_t)1000)
+#define BIT_LEN           ((uint16_t)100)
+#define RESET_P           ((uint16_t)500)
+#define BIT_ONE_P         ((uint16_t)10)
+#define BIT_ZERO_P        ((uint16_t)80)
+#define BIT_READ_P        ((uint16_t)5)
+#define RESET_BARRIER     ((uint16_t)550)
+#define ONE_ZERO_BARRIER  ((uint16_t)10)
+
+// answer for polling: conversion done
+#define CONVERSION_DONE     (0xff)
+
+/*
+ * thermometer commands
+ * send them with bus reset!
+ */
+// find devices
+#define OW_SEARCH_ROM       (0xf0)
+// read device (when it is alone on the bus)
+#define OW_READ_ROM         (0x33)
+// send device ID (after this command - 8 bytes of ID)
+#define OW_MATCH_ROM        (0x55)
+// broadcast command
+#define OW_SKIP_ROM         (0xcc)
+// find devices with critical conditions
+#define OW_ALARM_SEARCH     (0xec)
+/*
+ * thermometer functions
+ * send them without bus reset!
+ */
+// start themperature reading
+#define OW_CONVERT_T         (0x44)
+// write critical temperature to device's RAM
+#define OW_SCRATCHPAD        (0x4e)
+// read whole device flash
+#define OW_READ_SCRATCHPAD   (0xbe)
+// copy critical themperature from device's RAM to its EEPROM
+#define OW_COPY_SCRATCHPAD   (0x48)
+// copy critical themperature from EEPROM to RAM (when power on this operation runs automatically)
+#define OW_RECALL_E2         (0xb8)
+// check whether there is devices wich power up from bus
+#define OW_READ_POWER_SUPPLY (0xb4)
+
+/*
+ * thermometer identificator is: 8bits CRC, 48bits serial, 8bits device code (10h)
+ * Critical temperatures is T_H and T_L
+ * T_L is lowest allowed temperature
+ * T_H is highest -//-
+ * format T_H and T_L: 1bit sigh + 7bits of data
+ */
+
+
+/*
+ * RAM register:
+ * 0 - themperature: 1 ADU == 0.5 degrC
+ * 1 - sign (0 - T>0 degrC ==> T=byte0; 1 - T<0 degrC ==> T=byte0-0xff+1)
+ * 2 - T_H
+ * 3 - T_L
+ * 4 - 0xff (reserved)
+ * 5 - 0xff (reserved)
+ * 6 - COUNT_REMAIN (0x0c)
+ * 7 - COUNT PER DEGR (0x10)
+ * 8 - CRC
+ */
+
+// max amount of bits (20bytes x 8bits)
+#define NmeasurementMax     (160)
+// reset pulse length (ms+1..2)
+#define DS18_RESETPULSE_LEN (3)
+// max length of measurement (ms+1..2)
+#define DS18_MEASUR_LEN     (800)
+// maximal received data bytes
+#define IMAXCTR             (10)
+
+static uint8_t DS18ID[8] = {0}, matchID = 0;
+
+static void (*ow_process_resdata)() = NULL; // what to do with received data
+
+static DS18_state dsstate = DS18_SLEEP;
+static uint32_t Tstart = 0; // time of start pulse
+// sent data,  + 1 zero for last
+static uint8_t CC1array[NmeasurementMax];
+static uint8_t totbytesctr = 0; // total (i/o) data bytes counter
+static int cc1buff_ctr = 0;
+// received data
+static uint8_t CC2array[NmeasurementMax];
+static uint8_t receivectr = 0; // data bytes amount to receive
+// prepare buffers to sending
+#define OW_reset_buffer()   do{cc1buff_ctr = 0; receivectr = 0; totbytesctr = 0;}while(0)
+
+// several devices on line
+void DS18_setID(const uint8_t ID[8]){
+    uint32_t *O = (uint32_t*)DS18ID, *I = (uint32_t*)ID;
+    *O++ = *I++; *O = *I;
+    matchID = 1;
+#ifdef EBUG
+    USB_send("DS18_setID: ");
+    for(int i = 0; i < 8; ++i){
+        USB_send(" 0x");
+        printhex(DS18ID[i]);
+    }
+    USB_send("\n");
+#endif
+}
+// the only device on line
+void DS18_clearID(){
+    matchID = 0;
+}
+
+/**
+ * add next data byte
+ * @param ow_byte - byte to convert
+ */
+static uint8_t OW_add_byte(uint8_t ow_byte){
+    uint8_t i, byte;
+	for(i = 0; i < 8; i++){
+		if(ow_byte & 0x01){
+			byte = BIT_ONE_P;
+		}else{
+			byte = BIT_ZERO_P;
+		}
+		if(cc1buff_ctr == NmeasurementMax){
+			DBG("Tim2 buffer overflow\n");
+			return 0; // avoid buffer overflow
+		}
+		CC1array[cc1buff_ctr++] = byte;
+		ow_byte >>= 1;
+	}
+    ++totbytesctr;
+	return 1;
+}
+
+/**
+ * Adds Nbytes bytes 0xff  for reading sequence
+ */
+static uint8_t OW_add_read_seq(uint8_t Nbytes){
+	uint8_t i;
+	if(Nbytes == 0) return 0;
+    totbytesctr += Nbytes;
+    receivectr += Nbytes;
+	Nbytes *= 8; // 8 bits for each byte
+	for(i = 0; i < Nbytes; i++){
+		if(cc1buff_ctr == NmeasurementMax){
+			DBG("Tim2 buffer overflow\n");
+			return 0;
+		}
+		CC1array[cc1buff_ctr++] = BIT_READ_P;
+	}
+    DBG("add rseq, rctr="); DBG(i2str(receivectr)); DBG("\n");
+	return 1;
+}
+
+// read received data (not more than IMAXCTR bytes!)
+static uint8_t *OW_readbuf(){
+#ifdef EBUG
+    DBG("ctr1="); DBG(u2str(DMA1_Channel2->CNDTR)); DBG("\n");
+    DBG("ctr2="); DBG(u2str(DMA1_Channel3->CNDTR)); DBG("\n");
+    DBG("\nn\tCC1\tCC2\n");
+    for(int i = 0; i < cc1buff_ctr; ++i){
+        DBG(u2str(i)); DBG("\t"); DBG(u2str(CC1array[i]));
+        DBG("\t"); DBG(u2str(CC2array[i])); DBG("\n");
+    }
+#endif
+    static uint8_t got[IMAXCTR];
+    uint8_t *gptr = got;
+    DBG("rctr="); DBG(i2str(receivectr)); DBG("\n");
+    if(receivectr > IMAXCTR || receivectr == 0) return NULL;
+    uint8_t startidx = (totbytesctr - receivectr) * 8;
+    for(int i = startidx; i < cc1buff_ctr;){
+        uint8_t byte = 0;
+        for(int j = 0; j < 8; ++j){
+            byte >>= 1;
+            if(CC2array[i++] < ONE_ZERO_BARRIER) byte |= 0x80;
+        }
+        *gptr++ = byte;
+#ifdef EBUG
+        USB_send("byte: "); printhex(byte); USB_send("\n");
+#endif
+    }
+    return got;
+}
+
+DS18_state DS18_getstate(){return dsstate;}
+
+static void DS18_detect(){
+    DBG("DS18_detect()\n");
+    TIM1->ARR = RESET_LEN;
+    TIM1->CCR1 = RESET_P;
+    TIM1->CCR2 = 0; // after interrupt it should be RESET_P+Tpdhigh+Tpdlow (575..800ms)
+    TIM1->EGR = TIM_EGR_UG; // generate update to put CCR1 from buffer into register
+    TIM1->SR = 0;
+    // enable update IRQ
+    TIM1->DIER = TIM_DIER_UIE;
+    TIM1->CCR1 = 0; // next time level should be max
+    // PA8 as AF opendrain output
+    GPIOA->CRH = (GPIOA->CRH & ~(GPIO_CRH_MODE8 | GPIO_CRH_CNF8)) |
+            CRH(8, CNF_AFOD | MODE_FAST);
+    // turn TIM1 on in OPM mode
+    TIM1->CR1 = TIM_CR1_CEN | TIM_CR1_OPM | TIM_CR1_URS;
+    dsstate = DS18_DETECTING;
+}
+
+static void DS18_getReg(int n){
+    uint8_t *r = OW_readbuf();
+    if(!r || receivectr != n){
+        DBG("Bad read value!\n");
+        return;
+    }
+    printsp(r, n);
+}
+
+static int chkCRC(const uint8_t data[9]){
+    uint8_t crc = 0;
+    for(int n = 0; n < 8; ++n){
+        crc = crc ^ data[n];
+           for(int i = 0; i < 8; i++){
+               if(crc & 1)
+                   crc = (crc >> 1) ^ 0x8C;
+               else
+                   crc >>= 1;
+           }
+    }
+    //USB_send("got crc: "); printhex(crc); USB_send("\n");
+    if(data[8] == crc) return 0;
+    return 1;
+}
+
+// data processing functions
+static void DS18_gettemp(){ // calculate T
+    dsstate = DS18_SLEEP;
+#ifdef EBUG
+    for(int i = 0; i < NmeasurementMax; ++i){
+        DBG(u2str(i)); DBG("\t"); DBG(u2str(CC2array[i])); DBG("\n");
+    }
+#endif
+    uint8_t *r = OW_readbuf();
+    if(!r || receivectr != 9){
+        DBG("Bad count");
+        dsstate = DS18_ERROR;
+        return;
+    }
+    int ctr;
+    for(ctr = 0; ctr < 9; ++ctr){
+        if(r[ctr] != 0xff) break;
+    }
+    if(ctr == 9){
+        USB_send("Target ID not found");
+        return;
+    }
+    if(chkCRC(r)){
+        USB_send("CRC is wrong\n");
+        return;
+    }
+    uint16_t l = r[0], m = r[1], v;
+    int32_t t;
+    if(r[4] == 0xff){ // DS18S20
+        t = ((uint32_t)l) * 10;
+        t >>= 1;
+	}else{ // DS18B20
+        v = ((m & 7) << 8)| l;
+        t = ((uint32_t)v)*10;
+        t >>= 4;
+	}
+    if(m & 0x80) t = -t;
+    printT(t);
+}
+static void DS18_pollt(){ // poll T
+    uint8_t *r;
+    if((r = OW_readbuf()) && receivectr == 1){
+        if(*r == CONVERSION_DONE){
+            OW_reset_buffer();
+            if(matchID){ // add MATCH command & target ID
+                OW_add_byte(OW_MATCH_ROM);
+                for(int i = 0; i < 8; ++i)
+                    OW_add_byte(DS18ID[i]);
+            }else{
+                OW_add_byte(OW_SKIP_ROM);
+            }
+            OW_add_byte(OW_READ_SCRATCHPAD);
+            OW_add_read_seq(9);
+            ow_process_resdata = DS18_gettemp;
+            DS18_detect(); // reset
+            return;
+        }
+    }
+    OW_reset_buffer();
+    OW_add_read_seq(1); // send read seq waiting for end of conversion
+    ow_process_resdata = DS18_pollt;
+    dsstate = DS18_RDYTOSEND;
+}
+static void DS18_getID(){
+    DS18_getReg(8);
+}
+static void DS18_getSP(){
+    DS18_getReg(9);
+}
+
+// TIM1_CH1 & TIM1_CH2 are used for data sending & pulse length measurement
+// T1ch1 - DMA1Ch2, T1ch2 - DMA1Ch3
+void DS18_pinsetup(){
+    TIM1->CR1 = 0;
+    RCC->APB2ENR |= RCC_APB2ENR_IOPAEN | RCC_APB2ENR_TIM1EN | RCC_APB2ENR_AFIOEN;
+    RCC->AHBENR |= RCC_AHBENR_DMA1EN;
+    pin_set(GPIOA, 1<<8); // 1 @ line
+    // PA8 as opendrain output
+    GPIOA->CRH = (GPIOA->CRH & ~(GPIO_CRH_MODE8 | GPIO_CRH_CNF8)) |
+            CRH(8, CNF_ODOUTPUT | MODE_FAST);
+    TIM1->PSC = 71; // 1MHz
+    // CC1 is output (PWM mode 1, active->inactive, enable preload), CC2 is input @TI1
+    TIM1->CCMR1 = TIM_CCMR1_OC1M_2 | TIM_CCMR1_OC1M_1 | TIM_CCMR1_OC1PE |
+            TIM_CCMR1_CC2S_1;
+    // enable CC1 & CC2, CC1 active low
+    TIM1->CCER = TIM_CCER_CC1E | TIM_CCER_CC2E | TIM_CCER_CC1P;
+    TIM1->DIER = 0; // disable IRQ & DMA events
+    // main output enable
+    TIM1->BDTR = TIM_BDTR_MOE;
+    // T1Ch2: per->mem, T1Ch1: mem->per; 16bit->8bit,
+    DMA1_Channel2->CCR = DMA_CCR_MINC | DMA_CCR_PSIZE_0 | DMA_CCR_TCIE | DMA_CCR_DIR;
+    DMA1_Channel3->CCR = DMA_CCR_MINC | DMA_CCR_PSIZE_0 | DMA_CCR_TCIE;
+    DMA1_Channel2->CPAR = (uint32_t)&TIM1->CCR1;
+    DMA1_Channel3->CPAR = (uint32_t)&TIM1->CCR2;
+    TIM1->CR1 = TIM_CR1_URS; // only ARR overflow generates interrupt
+
+    NVIC_EnableIRQ(TIM1_UP_IRQn); // last interrupt to turn timer off
+    NVIC_EnableIRQ(DMA1_Channel2_IRQn);
+    dsstate = DS18_SLEEP;
+}
+
+// start measurement
+static void DS18_startmeas(uint32_t Tms){
+    DBG("startmeas()\n");
+    dsstate = DS18_READING;
+    Tstart = Tms;
+    DMA1->IFCR = DMA_IFCR_CGIF1 | DMA_IFCR_CGIF2; // clear all flags
+    DMA1_Channel2->CMAR = (uint32_t)CC1array;
+    DMA1_Channel3->CMAR = (uint32_t)CC2array;
+    DMA1_Channel2->CNDTR = cc1buff_ctr+1; // +1 for last works
+    DMA1_Channel3->CNDTR = cc1buff_ctr;
+    // enable both DMA channels
+    DMA1_Channel2->CCR |= DMA_CCR_EN;
+    DMA1_Channel3->CCR |= DMA_CCR_EN;
+    // enable  DMA events generation
+    TIM1->DIER = TIM_DIER_CC1DE | TIM_DIER_CC2DE;
+    TIM1->ARR = BIT_LEN;
+    TIM1->SR = 0;
+    GPIOA->CRH = (GPIOA->CRH & ~(GPIO_CRH_MODE8 | GPIO_CRH_CNF8)) |
+            CRH(8, CNF_AFOD | MODE_FAST);
+    // turn TIM1 on
+    TIM1->CR1 = TIM_CR1_CEN | TIM_CR1_URS;
+}
+
+
+static void DS18_stopmeas(){
+    DBG("stopmeas()\n");
+    // stop timer
+    TIM1->CR1 = 0;
+    // disable DMA channel
+    DMA1_Channel2->CCR &= ~DMA_CCR_EN;
+    DMA1_Channel3->CCR &= ~DMA_CCR_EN;
+#ifdef EBUG
+    DBG("ctr="); DBG(u2str(DMA1_Channel2->CNDTR)); DBG("\nn\tCC1\n");
+    int nmax = NmeasurementMax - DMA1_Channel2->CNDTR;
+    for(int i = 0; i < nmax; ++i){
+        DBG(u2str(i)); DBG("\t"); DBG(u2str(CC1array[i])); DBG("\n");
+    }
+#endif
+    dsstate = DS18_ERROR;
+}
+
+// processing, Tms - current time in milliseconds
+void DS18_process(uint32_t Tms){
+    switch(dsstate){
+        case DS18_DETDONE:
+            DBG("TIM1->CCR2="); DBG(u2str(TIM1->CCR2)); DBG("\n");
+           /* DBG("SR="); DBG(u2str(TIM1->SR)); DBG("\n");
+            if(TIM1->SR & TIM_SR_CC2OF){
+                TIM1->SR = 0; DBG("Overcapture!\n");
+            }*/
+            if(TIM1->CCR2 > RESET_BARRIER) DS18_startmeas(Tms);
+            else dsstate = DS18_ERROR;
+        break;
+        case DS18_RDYTOSEND: // send data without reset pulse
+            DS18_startmeas(Tms);
+        break;
+        case DS18_READING:
+            if(Tms - Tstart > DS18_MEASUR_LEN)
+                DS18_stopmeas();
+        break;
+        case DS18_GOTANSWER:
+            // disable DMA channels
+            DMA1_Channel2->CCR &= ~DMA_CCR_EN;
+            DMA1_Channel3->CCR &= ~DMA_CCR_EN;
+            dsstate = DS18_SLEEP;
+            if(ow_process_resdata) ow_process_resdata();
+        break;
+        default:
+            return;
+    }
+}
+
+int DS18_start(){
+    if(dsstate != DS18_SLEEP && dsstate != DS18_ERROR) return 0;
+    OW_reset_buffer();
+    OW_add_byte(OW_SKIP_ROM);
+	OW_add_byte(OW_CONVERT_T);
+	OW_add_read_seq(1); // send read seq waiting for end of conversion
+    DBG("start()\n");
+    ow_process_resdata = DS18_pollt; // after data will be done calculate T and show it
+    DS18_detect();
+    return 1;
+}
+
+int DS18_readID(){
+    if(dsstate != DS18_SLEEP && dsstate != DS18_ERROR) return 0;
+    OW_reset_buffer();
+	OW_add_byte(OW_READ_ROM);
+	OW_add_read_seq(8); // wait for 8 bytes
+    ow_process_resdata = DS18_getID;
+    DBG("readID()\n");
+    DS18_detect();
+    return 1;
+}
+
+int DS18_readScratchpad(){
+    if(dsstate != DS18_SLEEP && dsstate != DS18_ERROR) return 0;
+    OW_reset_buffer();
+    OW_add_byte(OW_SKIP_ROM);
+	OW_add_byte(OW_READ_SCRATCHPAD);
+	OW_add_read_seq(9);
+    ow_process_resdata = DS18_getSP;
+    DBG("readSP()\n");
+    DS18_detect();
+    return 1;
+}
+
+void dma1_channel2_isr(){ // wait for last data bit
+    DMA1->IFCR = DMA_IFCR_CGIF2;
+    TIM1->CR1 |= TIM_CR1_OPM;
+    TIM1->CCR1 = 0; // don't go to zero
+    TIM1->SR &= ~TIM_SR_UIF; // clear update flag (or interrupt will run just now)
+    TIM1->DIER |= TIM_DIER_UIE;
+}
+
+// update IRQ
+void tim1_up_isr(){
+    TIM1->SR = 0; // clear all flags (and overcapture too!) &= ~TIM_SR_UIF;
+    TIM1->CR1 = 0;
+    if(dsstate == DS18_DETECTING) dsstate = DS18_DETDONE;
+    else if(dsstate == DS18_READING) dsstate = DS18_GOTANSWER;
+}
+
+void DS18_poll(){
+    OW_reset_buffer();
+    OW_add_read_seq(1); // send read seq waiting for end of conversion
+    ow_process_resdata = DS18_pollt;
+    dsstate = DS18_RDYTOSEND;
+}

F1:F103/DS18/ds18.h

@@ -0,0 +1,49 @@
+/*
+ * This file is part of the DS18 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+#ifndef DHT_H__
+#define DHT_H__
+
+#include <stm32f1.h>
+
+
+// state of device
+typedef enum{
+    DS18_SLEEP,
+    DS18_RESETTING,
+    DS18_DETECTING,
+    DS18_DETDONE,
+    DS18_RDYTOSEND,
+    DS18_READING,
+    DS18_GOTANSWER,
+    DS18_ERROR
+} DS18_state;
+
+void DS18_pinsetup();
+int DS18_start();
+int DS18_readID();
+DS18_state DS18_getstate();
+void DS18_process(uint32_t Tms);
+int DS18_readScratchpad();
+void DS18_poll();
+
+void DS18_clearID();
+void DS18_setID(const uint8_t ID[8]);
+
+#endif // DHT_H__
+

F1:F103/DS18/hardware.c

@@ -0,0 +1,48 @@
+/*
+ * This file is part of the DS18 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "hardware.h"
+
+static inline void gpio_setup(){
+    // Enable clocks to the GPIO subsystems (PB for ADC), turn on AFIO clocking to disable SWD/JTAG
+    RCC->APB2ENR |= RCC_APB2ENR_IOPAEN | RCC_APB2ENR_IOPCEN | RCC_APB2ENR_AFIOEN;
+    // turn off SWJ/JTAG
+//    AFIO->MAPR = AFIO_MAPR_SWJ_CFG_DISABLE;
+    AFIO->MAPR = AFIO_MAPR_SWJ_CFG_JTAGDISABLE; // for PA15
+    // Set led as opendrain output
+    GPIOC->CRH = CRH(13, CNF_ODOUTPUT|MODE_SLOW);
+    // USB pullup (PA15) - pushpull output
+    GPIOA->CRH = CRH(15, CNF_PPOUTPUT|MODE_SLOW);
+}
+
+void hw_setup(){
+    gpio_setup();
+}
+
+void iwdg_setup(){
+    uint32_t tmout = 16000000;
+    RCC->CSR |= RCC_CSR_LSION;
+    while((RCC->CSR & RCC_CSR_LSIRDY) != RCC_CSR_LSIRDY){if(--tmout == 0) break;} /* (2) */
+    IWDG->KR = IWDG_START;
+    IWDG->KR = IWDG_WRITE_ACCESS;
+    IWDG->PR = IWDG_PR_PR_1;
+    IWDG->RLR = 1250;
+    tmout = 16000000;
+    while(IWDG->SR){if(--tmout == 0) break;}
+    IWDG->KR = IWDG_REFRESH;
+}

F1:F103/DS18/hardware.h

@@ -0,0 +1,42 @@
+/*
+ * This file is part of the DS18 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#ifndef __HARDWARE_H__
+#define __HARDWARE_H__
+
+#include "stm32f1.h"
+
+// LED0 - PC13 (bluepill), blinking each second
+#define LED0_port   GPIOC
+#define LED0_pin    (1<<13)
+
+// USB pullup (not present in bluepill, should be soldered) - PA15
+#define USBPU_port  GPIOA
+#define USBPU_pin   (1<<15)
+#define USBPU_ON()  pin_set(USBPU_port, USBPU_pin)
+#define USBPU_OFF() pin_clear(USBPU_port, USBPU_pin)
+
+#define LED_blink(x)    pin_toggle(x ## _port, x ## _pin)
+#define LED_on(x)       pin_clear(x ## _port, x ## _pin)
+#define LED_off(x)      pin_set(x ## _port, x ## _pin)
+
+void hw_setup();
+void iwdg_setup();
+
+#endif // __HARDWARE_H__

F1:F103/DS18/main.c

@@ -0,0 +1,92 @@
+/*
+ * This file is part of the DS18 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "ds18.h"
+#include "hardware.h"
+#include "proto.h"
+#include "usb.h"
+#include "usb_lib.h"
+
+volatile uint32_t Tms = 0;
+
+/* Called when systick fires */
+void sys_tick_handler(void){
+    ++Tms;
+}
+
+// usb getline
+char *get_USB(){
+    static char tmpbuf[512], *curptr = tmpbuf;
+    static int rest = 511;
+    uint8_t x = USB_receive(curptr);
+    curptr[x] = 0;
+    if(!x) return NULL;
+    if(curptr[x-1] == '\n'){
+        curptr = tmpbuf;
+        rest = 511;
+        return tmpbuf;
+    }
+    curptr += x; rest -= x;
+    if(rest <= 0){ // buffer overflow
+        curptr = tmpbuf;
+        rest = 511;
+    }
+    return NULL;
+}
+
+int main(void){
+    uint32_t lastT = 0;
+    sysreset();
+    StartHSE();
+    hw_setup();
+    SysTick_Config(72000);
+
+    RCC->CSR |= RCC_CSR_RMVF; // remove reset flags
+
+    USBPU_OFF();
+    USB_setup();
+    DS18_pinsetup();
+    //iwdg_setup();
+    USBPU_ON();
+
+    while (1){
+        IWDG->KR = IWDG_REFRESH; // refresh watchdog
+        if(lastT > Tms || Tms - lastT > 499){
+            LED_blink(LED0);
+            lastT = Tms;
+        }
+        DS18_process(Tms);
+        DS18_state st = DS18_getstate();
+        if(st == DS18_ERROR){
+            USB_send("Error with DS18, reinit\n");
+            DS18_pinsetup();
+        }
+        usb_proc();
+        char *txt, *ans;
+        if((txt = get_USB())){
+            IWDG->KR = IWDG_REFRESH;
+            ans = (char*)parse_cmd(txt);
+            if(ans){
+                uint16_t l = 0; char *p = ans;
+                while(*p++) l++;
+                USB_send(ans);
+            }
+        }
+    }
+    return 0;
+}

F1:F103/DS18/proto.c

@@ -0,0 +1,316 @@
+/*
+ * This file is part of the DS18 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "ds18.h"
+#include "proto.h"
+#include "usb.h"
+
+extern volatile uint32_t Tms;
+
+
+char *omit_spaces(const char *buf){
+    while(*buf){
+        if(*buf > ' ') break;
+        ++buf;
+    }
+    return (char*)buf;
+}
+
+// In case of overflow return `buf` and N==0xffffffff
+// read decimal number & return pointer to next non-number symbol
+static char *getdec(const char *buf, uint32_t *N){
+    char *start = (char*)buf;
+    uint32_t num = 0;
+    while(*buf){
+        char c = *buf;
+        if(c < '0' || c > '9'){
+            break;
+        }
+        if(num > 429496729 || (num == 429496729 && c > '5')){ // overflow
+            *N = 0xffffff;
+            return start;
+        }
+        num *= 10;
+        num += c - '0';
+        ++buf;
+    }
+    *N = num;
+    return (char*)buf;
+}
+// read hexadecimal number (without 0x prefix!)
+static char *gethex(const char *buf, uint32_t *N){
+    char *start = (char*)buf;
+    uint32_t num = 0;
+    while(*buf){
+        char c = *buf;
+        uint8_t M = 0;
+        if(c >= '0' && c <= '9'){
+            M = '0';
+        }else if(c >= 'A' && c <= 'F'){
+            M = 'A' - 10;
+        }else if(c >= 'a' && c <= 'f'){
+            M = 'a' - 10;
+        }
+        if(M){
+            if(num & 0xf0000000){ // overflow
+                *N = 0xffffff;
+                return start;
+            }
+            num <<= 4;
+            num += c - M;
+        }else{
+            break;
+        }
+        ++buf;
+    }
+    *N = num;
+    return (char*)buf;
+}
+// read octal number (without 0 prefix!)
+static char *getoct(const char *buf, uint32_t *N){
+    char *start = (char*)buf;
+    uint32_t num = 0;
+    while(*buf){
+        char c = *buf;
+        if(c < '0' || c > '7'){
+            break;
+        }
+        if(num & 0xe0000000){ // overflow
+            *N = 0xffffff;
+            return start;
+        }
+        num <<= 3;
+        num += c - '0';
+        ++buf;
+    }
+    *N = num;
+    return (char*)buf;
+}
+// read binary number (without b prefix!)
+static char *getbin(const char *buf, uint32_t *N){
+    char *start = (char*)buf;
+    uint32_t num = 0;
+    while(*buf){
+        char c = *buf;
+        if(c < '0' || c > '1'){
+            break;
+        }
+        if(num & 0x80000000){ // overflow
+            *N = 0xffffff;
+            return start;
+        }
+        num <<= 1;
+        if(c == '1') num |= 1;
+        ++buf;
+    }
+    *N = num;
+    return (char*)buf;
+}
+
+/**
+ * @brief getnum - read uint32_t from string (dec, hex or bin: 127, 0x7f, 0b1111111)
+ * @param buf - buffer with number and so on
+ * @param N   - the number read
+ * @return pointer to first non-number symbol in buf
+ *      (if it is == buf, there's no number or if *N==0xffffffff there was overflow)
+ */
+char *getnum(const char *txt, uint32_t *N){
+    char *nxt = NULL;
+    char *s = omit_spaces(txt);
+    if(*s == '0'){ // hex, oct or 0
+        if(s[1] == 'x' || s[1] == 'X'){ // hex
+            nxt = gethex(s+2, N);
+            if(nxt == s+2) nxt = (char*)txt;
+        }else if(s[1] > '0'-1 && s[1] < '8'){ // oct
+            nxt = getoct(s+1, N);
+            if(nxt == s+1) nxt = (char*)txt;
+        }else{ // 0
+            nxt = s+1;
+            *N = 0;
+        }
+    }else if(*s == 'b' || *s == 'B'){
+        nxt = getbin(s+1, N);
+        if(nxt == s+1) nxt = (char*)txt;
+    }else{
+        nxt = getdec(s, N);
+        if(nxt == s) nxt = (char*)txt;
+    }
+    return nxt;
+}
+
+static const char *helpmesg =
+        "'C' - clear match ROM\n"
+        "'D' - get DS18 state\n"
+        "'I' - get DS18 ID\n"
+        "'M' - start measurement\n"
+        "'P' - read scratchpad\n"
+        "'S' - set match ROM (S 0xaa 0xbb... - 8 bytes of ID)\n"
+        "'R' - software reset\n"
+        "'T' - get time from start\n"
+        "'W' - test watchdog\n"
+;
+
+// read 8 bytes of ROM and run SETROM
+static void setROM(const char *buf){
+    uint8_t ID[8];
+    uint32_t N;
+    for(int i = 0; i < 8; ++i){
+        char *nxt = getnum(buf, &N);
+        if(nxt == buf || N > 0xff){
+            USB_send("Wrong data: ");
+            USB_send(buf);
+            return;
+        }
+        ID[i] = (uint8_t) N;
+        buf = nxt;
+    }
+    DS18_setID(ID);
+    USB_send("Set ID to:");
+    for(int i = 0; i < 8; ++i){
+        USB_send(" 0x");
+        printhex(ID[i]);
+    }
+    USB_send("\n");
+}
+
+const char *parse_cmd(const char *buf){
+    if(buf[1] == '\n'){
+        switch(*buf){
+            case 'C':
+                DS18_clearID();
+                return "Don't send MATCH ROM\n";
+            break;
+            case 'D':
+                switch(DS18_getstate()){
+                    case DS18_SLEEP:
+                        return "Sleeping\n";
+                    case DS18_RESETTING:
+                        return "Resetting\n";
+                    case DS18_DETECTING:
+                        return "Detecting\n";
+                    case DS18_DETDONE:
+                        return "Detection done\n";
+                    case DS18_READING:
+                        return "Measuring\n";
+                    case DS18_GOTANSWER:
+                        return "Results are ready\n";
+                    default:
+                        return "Not found\n";
+                }
+            break;
+            case 'I':
+                if(DS18_readID()) return "Reading ID..\n";
+                else return "Error\n";
+            case 'M':
+                if(DS18_start()) return "Started\n";
+                else return "Wait a little\n";
+            break;
+    /*        case 'p':
+                DS18_poll();
+                return "polling\n";
+            break;*/
+            case 'P':
+                if(DS18_readScratchpad()) return "Reading scr..\n";
+                else return "Error\n";
+            break;
+            case 'R':
+                USB_send("Soft reset\n");
+                NVIC_SystemReset();
+            break;
+            case 'T':
+                USB_send("T=");
+                USB_send(u2str(Tms));
+                USB_send("ms\n");
+            break;
+            case 'W':
+                USB_send("Wait for reboot\n");
+                while(1){nop();};
+            break;
+            default: // help
+                return helpmesg;
+            break;
+        }
+    }else{ // several letters
+        switch(*buf){
+            case 'S':
+                setROM(buf + 1);
+            break;
+            default:
+                return buf;
+        }
+    }
+    return NULL;
+}
+
+static char *_2str(uint32_t  val, uint8_t minus){
+    static char strbuf[12];
+    char *bufptr = &strbuf[11];
+    *bufptr = 0;
+    if(!val){
+        *(--bufptr) = '0';
+    }else{
+        while(val){
+            *(--bufptr) = val % 10 + '0';
+            val /= 10;
+        }
+    }
+    if(minus) *(--bufptr) = '-';
+    return bufptr;
+}
+
+// return string with number `val`
+char *u2str(uint32_t val){
+    return _2str(val, 0);
+}
+char *i2str(int32_t i){
+    uint8_t minus = 0;
+    uint32_t val;
+    if(i < 0){
+        minus = 1;
+        val = -i;
+    }else val = i;
+    return _2str(val, minus);
+}
+
+void printhex(uint8_t x){
+    char b[3];
+    uint8_t H(uint8_t c){
+        if(c < 10)
+            return (c + '0');
+        else
+            return (c + 'a' - 10);
+    }
+    b[0] = H(x >> 4);
+    b[1] = H(x & 0x0f);
+    b[2] = 0;
+    USB_send(b);
+}
+
+void printT(int16_t T){ // print temperature value, this function should be called from ds18.c
+    USB_send("Temperature="); USB_send(i2str(T));
+    USB_send("\n");
+}
+
+void printsp(uint8_t *b, int n){
+    USB_send("Regvalue:");
+    for(int i = 0; i < n; ++i){
+        USB_send(" 0x");
+        printhex(b[i]);
+    }
+    USB_send("\n");
+}

F1:F103/DS18/proto.h

@@ -0,0 +1,31 @@
+/*
+ * This file is part of the DS18 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#pragma once
+#ifndef PROTO_H__
+#define PROTO_H__
+
+#include <stm32f1.h>
+
+const char *parse_cmd(const char *buf);
+char *u2str(uint32_t val);
+char *i2str(int32_t i);
+void printT(int16_t T);
+void printsp(uint8_t *b, int n);
+void printhex(uint8_t x);
+
+#endif // PROTO_H__

F1:F103/DS18/usb.c

@@ -0,0 +1,162 @@
+/*
+ * This file is part of the DS18 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "usb.h"
+#include "usb_lib.h"
+
+static volatile uint8_t tx_succesfull = 1;
+static volatile uint8_t rxNE = 0;
+
+// interrupt IN handler (never used?)
+static void EP1_Handler(){
+    uint16_t epstatus = KEEP_DTOG(USB->EPnR[1]);
+    if(RX_FLAG(epstatus)) epstatus = (epstatus & ~USB_EPnR_STAT_TX) ^ USB_EPnR_STAT_RX; // set valid RX
+    else epstatus = epstatus & ~(USB_EPnR_STAT_TX|USB_EPnR_STAT_RX);
+    // clear CTR
+    epstatus = (epstatus & ~(USB_EPnR_CTR_RX|USB_EPnR_CTR_TX));
+    USB->EPnR[1] = epstatus;
+}
+
+// data IN/OUT handlers
+static void transmit_Handler(){ // EP3IN
+    tx_succesfull = 1;
+    uint16_t epstatus = KEEP_DTOG_STAT(USB->EPnR[3]);
+    // clear CTR keep DTOGs & STATs
+    USB->EPnR[3] = (epstatus & ~(USB_EPnR_CTR_TX)); // clear TX ctr
+}
+
+static void receive_Handler(){ // EP2OUT
+    rxNE = 1;
+    uint16_t epstatus = KEEP_DTOG_STAT(USB->EPnR[2]);
+    USB->EPnR[2] = (epstatus & ~(USB_EPnR_CTR_RX)); // clear RX ctr
+}
+
+void USB_setup(){
+    NVIC_DisableIRQ(USB_LP_CAN1_RX0_IRQn);
+    NVIC_DisableIRQ(USB_HP_CAN1_TX_IRQn);
+    RCC->APB1ENR |= RCC_APB1ENR_USBEN;
+    USB->CNTR   = USB_CNTR_FRES; // Force USB Reset
+    for(uint32_t ctr = 0; ctr < 72000; ++ctr) nop(); // wait >1ms
+    //uint32_t ctr = 0;
+    USB->CNTR   = 0;
+    USB->BTABLE = 0;
+    USB->DADDR  = 0;
+    USB->ISTR   = 0;
+    USB->CNTR   = USB_CNTR_RESETM | USB_CNTR_WKUPM; // allow only wakeup & reset interrupts
+    NVIC_EnableIRQ(USB_LP_CAN1_RX0_IRQn);
+}
+
+static int usbwr(const uint8_t *buf, uint16_t l){
+    uint32_t ctra = 1000000;
+    while(--ctra && tx_succesfull == 0){
+        IWDG->KR = IWDG_REFRESH;
+    }
+    tx_succesfull = 0;
+    EP_Write(3, buf, l);
+    ctra = 1000000;
+    while(--ctra && tx_succesfull == 0){
+        IWDG->KR = IWDG_REFRESH;
+    }
+    if(tx_succesfull == 0){usbON = 0; return 1;} // usb is OFF?
+    return 0;
+}
+
+static char usbbuff[USB_TXBUFSZ-1]; // temporary buffer (63 - to prevent need of ZLP)
+static uint8_t buflen = 0; // amount of symbols in usbbuff
+
+// send next up to 63 bytes of data in usbbuff
+static void send_next(){
+    if(!buflen || !tx_succesfull) return;
+    tx_succesfull = 0;
+    EP_Write(3, (uint8_t*)usbbuff, buflen);
+    buflen = 0;
+}
+
+// unblocking sending - just fill a buffer
+void USB_send(const char *buf){
+    if(!usbON) return;
+    uint16_t len = 0;
+    const char *b = buf;
+    while(*b++) ++len;
+    if(len > USB_TXBUFSZ-1 - buflen){
+        usbwr((uint8_t*)usbbuff, buflen);
+        buflen = 0;
+    }
+    if(len > USB_TXBUFSZ-1){
+        USB_send_blk(buf, len);
+        return;
+    }
+    while(len--) usbbuff[buflen++] = *buf++;
+}
+
+// blocking sending
+void USB_send_blk(const char *buf, uint16_t len){
+    if(!usbON || !len) return; // USB disconnected
+    if(buflen){
+        usbwr((uint8_t*)usbbuff, buflen);
+        buflen = 0;
+    }
+    int needzlp = 0;
+    while(len){
+        if(len == USB_TXBUFSZ) needzlp = 1;
+        uint16_t s = (len > USB_TXBUFSZ) ? USB_TXBUFSZ : len;
+        if(usbwr((uint8_t*)buf, s)) return;
+        len -= s;
+        buf += s;
+    }
+    if(needzlp){
+        usbwr(NULL, 0);
+    }
+}
+
+void usb_proc(){
+    switch(USB_Dev.USB_Status){
+        case USB_STATE_CONFIGURED:
+            // make new BULK endpoint
+            // Buffer have 1024 bytes, but last 256 we use for CAN bus (30.2 of RM: USB main features)
+            EP_Init(1, EP_TYPE_INTERRUPT, USB_EP1BUFSZ, 0, EP1_Handler); // IN1 - transmit
+            EP_Init(2, EP_TYPE_BULK, 0, USB_RXBUFSZ, receive_Handler); // OUT2 - receive data
+            EP_Init(3, EP_TYPE_BULK, USB_TXBUFSZ, 0, transmit_Handler); // IN3 - transmit data
+            USB_Dev.USB_Status = USB_STATE_CONNECTED;
+        break;
+        case USB_STATE_DEFAULT:
+        case USB_STATE_ADDRESSED:
+            if(usbON){
+                usbON = 0;
+            }
+        break;
+        default: // USB_STATE_CONNECTED - send next data portion
+            if(!usbON) return;
+            send_next();
+    }
+}
+
+/**
+ * @brief USB_receive
+ * @param buf (i) - buffer[64] for received data
+ * @return amount of received bytes
+ */
+uint8_t USB_receive(char *buf){
+    if(!usbON || !rxNE) return 0;
+    uint8_t sz = EP_Read(2, (uint16_t*)buf);
+    uint16_t epstatus = KEEP_DTOG(USB->EPnR[2]);
+    // keep stat_tx & set ACK rx
+    USB->EPnR[2] = (epstatus & ~(USB_EPnR_STAT_TX)) ^ USB_EPnR_STAT_RX;
+    rxNE = 0;
+    return sz;
+}

F1:F103/DS18/usb.h

@@ -0,0 +1,33 @@
+/*
+ * This file is part of the DS18 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#ifndef __USB_H__
+#define __USB_H__
+
+#include "hardware.h"
+
+#define BUFFSIZE   (64)
+
+void USB_setup();
+void usb_proc();
+void USB_send(const char *buf);
+void USB_send_blk(const char *buf, uint16_t len);
+uint8_t USB_receive(char *buf);
+
+#endif // __USB_H__

F1:F103/DS18/usb_defs.h

@@ -0,0 +1,102 @@
+/*
+ * This file is part of the DS18 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#ifndef __USB_DEFS_H__
+#define __USB_DEFS_H__
+
+#include <stm32f1.h>
+
+// max endpoints number
+#define STM32ENDPOINTS          8
+/**
+ *                 Buffers size definition
+ **/
+#define USB_BTABLE_SIZE         512
+// first 64 bytes of USB_BTABLE are registers!
+//#define USB_EP0_BASEADDR        64
+// for USB FS EP0 buffers are from 8 to 64 bytes long (64 for PL2303)
+#define USB_EP0_BUFSZ           64
+// USB transmit buffer size (64 for PL2303)
+#define USB_TXBUFSZ             64
+// USB receive buffer size (64 for PL2303)
+#define USB_RXBUFSZ             64
+// EP1 - interrupt - buffer size
+#define USB_EP1BUFSZ            8
+
+#define USB_BTABLE_BASE         0x40006000
+#define USB_BASE                ((uint32_t)0x40005C00)
+#define USB                     ((USB_TypeDef *) USB_BASE)
+
+#ifdef USB_BTABLE
+#undef USB_BTABLE
+#endif
+#define USB_BTABLE              ((USB_BtableDef *)(USB_BTABLE_BASE))
+#define USB_ISTR_EPID           0x0000000F
+#define USB_FNR_LSOF_0          0x00000800
+#define USB_FNR_lSOF_1          0x00001000
+#define USB_LPMCSR_BESL_0       0x00000010
+#define USB_LPMCSR_BESL_1       0x00000020
+#define USB_LPMCSR_BESL_2       0x00000040
+#define USB_LPMCSR_BESL_3       0x00000080
+#define USB_EPnR_CTR_RX         0x00008000
+#define USB_EPnR_DTOG_RX        0x00004000
+#define USB_EPnR_STAT_RX        0x00003000
+#define USB_EPnR_STAT_RX_0      0x00001000
+#define USB_EPnR_STAT_RX_1      0x00002000
+#define USB_EPnR_SETUP          0x00000800
+#define USB_EPnR_EP_TYPE        0x00000600
+#define USB_EPnR_EP_TYPE_0      0x00000200
+#define USB_EPnR_EP_TYPE_1      0x00000400
+#define USB_EPnR_EP_KIND        0x00000100
+#define USB_EPnR_CTR_TX         0x00000080
+#define USB_EPnR_DTOG_TX        0x00000040
+#define USB_EPnR_STAT_TX        0x00000030
+#define USB_EPnR_STAT_TX_0      0x00000010
+#define USB_EPnR_STAT_TX_1      0x00000020
+#define USB_EPnR_EA             0x0000000F
+#define USB_COUNTn_RX_BLSIZE    0x00008000
+#define USB_COUNTn_NUM_BLOCK    0x00007C00
+#define USB_COUNTn_RX           0x0000003F
+
+#ifdef USB_TypeDef
+#define USB_TypeDef USB_TypeDef_custom
+#endif
+
+typedef struct {
+    __IO uint32_t EPnR[STM32ENDPOINTS];
+    __IO uint32_t RESERVED[STM32ENDPOINTS];
+    __IO uint32_t CNTR;
+    __IO uint32_t ISTR;
+    __IO uint32_t FNR;
+    __IO uint32_t DADDR;
+    __IO uint32_t BTABLE;
+} USB_TypeDef;
+
+typedef struct{
+    __IO uint32_t USB_ADDR_TX;
+    __IO uint32_t USB_COUNT_TX;
+    __IO uint32_t USB_ADDR_RX;
+    __IO uint32_t USB_COUNT_RX;
+} USB_EPDATA_TypeDef;
+
+typedef struct{
+    __IO USB_EPDATA_TypeDef EP[STM32ENDPOINTS];
+} USB_BtableDef;
+
+#endif // __USB_DEFS_H__

F1:F103/DS18/usb_lib.c

@@ -0,0 +1,476 @@
+/*
+ * This file is part of the DS18 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <stdint.h>
+#include "usb_lib.h"
+
+ep_t endpoints[STM32ENDPOINTS];
+
+usb_dev_t USB_Dev;
+static usb_LineCoding lineCoding = {115200, 0, 0, 8};
+static config_pack_t setup_packet;
+static uint8_t ep0databuf[EP0DATABUF_SIZE];
+static uint8_t ep0dbuflen = 0;
+
+usb_LineCoding getLineCoding(){return lineCoding;}
+
+uint8_t usbON = 0; // device disconnected from terminal
+
+// definition of parts common for USB_DeviceDescriptor & USB_DeviceQualifierDescriptor
+#define bcdUSB_L        0x10
+#define bcdUSB_H        0x01
+#define bDeviceClass    0
+#define bDeviceSubClass 0
+#define bDeviceProtocol 0
+#define bNumConfigurations 1
+
+static const uint8_t USB_DeviceDescriptor[] = {
+        18,     // bLength
+        0x01,   // bDescriptorType - Device descriptor
+        bcdUSB_L,   // bcdUSB_L - 1.10
+        bcdUSB_H,   // bcdUSB_H
+        bDeviceClass,   // bDeviceClass - USB_COMM
+        bDeviceSubClass,   // bDeviceSubClass
+        bDeviceProtocol,   // bDeviceProtocol
+        USB_EP0_BUFSZ,   // bMaxPacketSize
+        0x7b,   // idVendor_L PL2303: VID=0x067b, PID=0x2303
+        0x06,   // idVendor_H
+        0x03,   // idProduct_L
+        0x23,   // idProduct_H
+        0x00,   // bcdDevice_Ver_L
+        0x03,   // bcdDevice_Ver_H
+        0x01,   // iManufacturer
+        0x02,   // iProduct
+        0x00,   // iSerialNumber
+        bNumConfigurations    // bNumConfigurations
+};
+
+static const uint8_t USB_DeviceQualifierDescriptor[] = {
+        10,     //bLength
+        0x06,   // bDescriptorType - Device qualifier
+        bcdUSB_L,   // bcdUSB_L
+        bcdUSB_H,   // bcdUSB_H
+        bDeviceClass,   // bDeviceClass
+        bDeviceSubClass,   // bDeviceSubClass
+        bDeviceProtocol,   // bDeviceProtocol
+        USB_EP0_BUFSZ,   // bMaxPacketSize0
+        bNumConfigurations,   // bNumConfigurations
+        0x00    // Reserved
+};
+
+static const uint8_t USB_ConfigDescriptor[] = {
+        /*Configuration Descriptor*/
+        0x09, /* bLength: Configuration Descriptor size */
+        0x02, /* bDescriptorType: Configuration */
+        39,   /* wTotalLength:no of returned bytes */
+        0x00,
+        0x01, /* bNumInterfaces: 1 interface */
+        0x01, /* bConfigurationValue: Configuration value */
+        0x00, /* iConfiguration: Index of string descriptor describing the configuration */
+        0xa0, /* bmAttributes - Bus powered, Remote wakeup */
+        0x32, /* MaxPower 100 mA */
+
+        /*---------------------------------------------------------------------------*/
+
+        /*Interface Descriptor */
+        0x09, /* bLength: Interface Descriptor size */
+        0x04, /* bDescriptorType: Interface */
+        0x00, /* bInterfaceNumber: Number of Interface */
+        0x00, /* bAlternateSetting: Alternate setting */
+        0x03, /* bNumEndpoints: 3 endpoints used */
+        0xff, /* bInterfaceClass */
+        0x00, /* bInterfaceSubClass */
+        0x00, /* bInterfaceProtocol */
+        0x00, /* iInterface: */
+///////////////////////////////////////////////////
+        /*Endpoint 1 Descriptor*/
+        0x07, /* bLength: Endpoint Descriptor size */
+        0x05, /* bDescriptorType: Endpoint */
+        0x81, /* bEndpointAddress IN1 */
+        0x03, /* bmAttributes: Interrupt */
+        0x0a, /* wMaxPacketSize LO: */
+        0x00, /* wMaxPacketSize HI: */
+        0x01, /* bInterval: */
+
+        /*Endpoint OUT2 Descriptor*/
+        0x07, /* bLength: Endpoint Descriptor size */
+        0x05, /* bDescriptorType: Endpoint */
+        0x02, /* bEndpointAddress: OUT2 */
+        0x02, /* bmAttributes: Bulk */
+        (USB_RXBUFSZ & 0xff), /* wMaxPacketSize: 64 */
+        (USB_RXBUFSZ >> 8),
+        0x00, /* bInterval: ignore for Bulk transfer */
+
+        /*Endpoint IN3 Descriptor*/
+        0x07, /* bLength: Endpoint Descriptor size */
+        0x05, /* bDescriptorType: Endpoint */
+        0x83, /* bEndpointAddress IN3 */
+        0x02, /* bmAttributes: Bulk */
+        (USB_TXBUFSZ & 0xff), /* wMaxPacketSize: 64 */
+        (USB_TXBUFSZ >> 8),
+        0x00, /* bInterval: ignore for Bulk transfer */
+};
+
+_USB_LANG_ID_(USB_StringLangDescriptor, LANG_US);
+// these descriptors are not used in PL2303 emulator!
+_USB_STRING_(USB_StringSerialDescriptor, u"0");
+_USB_STRING_(USB_StringManufacturingDescriptor, u"Prolific Technology Inc.");
+_USB_STRING_(USB_StringProdDescriptor, u"USB-Serial Controller");
+
+/*
+ * default handlers
+ */
+// SET_LINE_CODING
+void WEAK linecoding_handler(usb_LineCoding __attribute__((unused)) *lc){
+}
+
+// SET_CONTROL_LINE_STATE
+void WEAK clstate_handler(uint16_t __attribute__((unused)) val){
+}
+
+// SEND_BREAK
+void WEAK break_handler(){
+}
+
+// handler of vendor requests
+void WEAK vendor_handler(config_pack_t *packet){
+    if(packet->bmRequestType & 0x80){ // read
+        uint8_t c;
+        switch(packet->wValue){
+            case 0x8484:
+                c = 2;
+            break;
+            case 0x0080:
+                c = 1;
+            break;
+            case 0x8686:
+                c = 0xaa;
+            break;
+            default:
+                c = 0;
+        }
+        EP_WriteIRQ(0, &c, 1);
+    }else{ // write ZLP
+        EP_WriteIRQ(0, (uint8_t *)0, 0);
+    }
+}
+
+static void wr0(const uint8_t *buf, uint16_t size){
+    if(setup_packet.wLength < size) size = setup_packet.wLength; // shortened request
+    if(size < endpoints[0].txbufsz){
+        EP_WriteIRQ(0, buf, size);
+        return;
+    }
+    while(size){
+        uint16_t l = size;
+        if(l > endpoints[0].txbufsz) l = endpoints[0].txbufsz;
+        EP_WriteIRQ(0, buf, l);
+        buf += l;
+        size -= l;
+        uint8_t needzlp = (l == endpoints[0].txbufsz) ? 1 : 0;
+        if(size || needzlp){ // send last data buffer
+            uint16_t status = KEEP_DTOG(USB->EPnR[0]);
+            // keep DTOGs, clear CTR_RX,TX, set TX VALID, leave stat_Rx
+            USB->EPnR[0] = (status & ~(USB_EPnR_CTR_RX|USB_EPnR_CTR_TX|USB_EPnR_STAT_RX))
+                            ^ USB_EPnR_STAT_TX;
+            uint32_t ctr = 1000000;
+            while(--ctr && (USB->ISTR & USB_ISTR_CTR) == 0){IWDG->KR = IWDG_REFRESH;};
+            if((USB->ISTR & USB_ISTR_CTR) == 0){
+                return;
+            }
+            if(needzlp) EP_WriteIRQ(0, (uint8_t*)0, 0);
+        }
+    }
+}
+
+static inline void get_descriptor(){
+    switch(setup_packet.wValue){
+        case DEVICE_DESCRIPTOR:
+            wr0(USB_DeviceDescriptor, sizeof(USB_DeviceDescriptor));
+        break;
+        case CONFIGURATION_DESCRIPTOR:
+            wr0(USB_ConfigDescriptor, sizeof(USB_ConfigDescriptor));
+        break;
+        case STRING_LANG_DESCRIPTOR:
+            wr0((const uint8_t *)&USB_StringLangDescriptor, STRING_LANG_DESCRIPTOR_SIZE_BYTE);
+        break;
+        case STRING_MAN_DESCRIPTOR:
+            wr0((const uint8_t *)&USB_StringManufacturingDescriptor, USB_StringManufacturingDescriptor.bLength);
+        break;
+        case STRING_PROD_DESCRIPTOR:
+            wr0((const uint8_t *)&USB_StringProdDescriptor, USB_StringProdDescriptor.bLength);
+        break;
+        case STRING_SN_DESCRIPTOR:
+            wr0((const uint8_t *)&USB_StringSerialDescriptor, USB_StringSerialDescriptor.bLength);
+        break;
+        case DEVICE_QUALIFIER_DESCRIPTOR:
+            wr0(USB_DeviceQualifierDescriptor, USB_DeviceQualifierDescriptor[0]);
+        break;
+        default:
+        break;
+    }
+}
+
+static uint8_t configuration = 0; // reply for GET_CONFIGURATION (==1 if configured)
+static inline void std_d2h_req(){
+    uint16_t status = 0; // bus powered
+    switch(setup_packet.bRequest){
+        case GET_DESCRIPTOR:
+            get_descriptor();
+        break;
+        case GET_STATUS:
+            EP_WriteIRQ(0, (uint8_t *)&status, 2); // send status: Bus Powered
+        break;
+        case GET_CONFIGURATION:
+            EP_WriteIRQ(0, &configuration, 1);
+        break;
+        default:
+        break;
+    }
+}
+
+static inline void std_h2d_req(){
+    switch(setup_packet.bRequest){
+        case SET_ADDRESS:
+            // new address will be assigned later - after  acknowlegement or request to host
+            USB_Dev.USB_Addr = setup_packet.wValue;
+        break;
+        case SET_CONFIGURATION:
+            // Now device configured
+            USB_Dev.USB_Status = USB_STATE_CONFIGURED;
+            configuration = setup_packet.wValue;
+        break;
+        default:
+        break;
+    }
+}
+
+/*
+bmRequestType: 76543210
+7    direction: 0 - host->device, 1 - device->host
+65   type: 0 - standard, 1 - class, 2 - vendor
+4..0 getter: 0 - device, 1 - interface, 2 - endpoint, 3 - other
+*/
+/**
+ * Endpoint0 (control) handler
+ */
+static void EP0_Handler(){
+    uint16_t epstatus = USB->EPnR[0]; // EP0R on input -> return this value after modifications
+    uint8_t reqtype = setup_packet.bmRequestType & 0x7f;
+    uint8_t dev2host = (setup_packet.bmRequestType & 0x80) ? 1 : 0;
+    int rxflag = RX_FLAG(epstatus);
+    if(rxflag && SETUP_FLAG(epstatus)){
+        switch(reqtype){
+            case STANDARD_DEVICE_REQUEST_TYPE: // standard device request
+                if(dev2host){
+                    std_d2h_req();
+                }else{
+                    std_h2d_req();
+                    EP_WriteIRQ(0, (uint8_t *)0, 0);
+                }
+            break;
+            case STANDARD_ENDPOINT_REQUEST_TYPE: // standard endpoint request
+                if(setup_packet.bRequest == CLEAR_FEATURE){
+                    EP_WriteIRQ(0, (uint8_t *)0, 0);
+                }
+            break;
+            case VENDOR_REQUEST_TYPE:
+                vendor_handler(&setup_packet);
+            break;
+            case CONTROL_REQUEST_TYPE:
+                switch(setup_packet.bRequest){
+                    case GET_LINE_CODING:
+                        EP_WriteIRQ(0, (uint8_t*)&lineCoding, sizeof(lineCoding));
+                    break;
+                    case SET_LINE_CODING: // omit this for next stage, when data will come
+                    break;
+                    case SET_CONTROL_LINE_STATE:
+                        usbON = 1;
+                        clstate_handler(setup_packet.wValue);
+                    break;
+                    case SEND_BREAK:
+                        usbON = 0;
+                        break_handler();
+                    break;
+                    default:
+                    break;
+                }
+                if(setup_packet.bRequest != GET_LINE_CODING) EP_WriteIRQ(0, (uint8_t *)0, 0); // write acknowledgement
+            break;
+            default:
+                EP_WriteIRQ(0, (uint8_t *)0, 0);
+        }
+    }else if(rxflag){ // got data over EP0 or host acknowlegement
+        if(endpoints[0].rx_cnt){
+            if(setup_packet.bRequest == SET_LINE_CODING){
+                linecoding_handler((usb_LineCoding*)ep0databuf);
+            }
+        }
+    } else if(TX_FLAG(epstatus)){ // package transmitted
+        // now we can change address after enumeration
+        if ((USB->DADDR & USB_DADDR_ADD) != USB_Dev.USB_Addr){
+            USB->DADDR = USB_DADDR_EF | USB_Dev.USB_Addr;
+            // change state to ADRESSED
+            USB_Dev.USB_Status = USB_STATE_ADDRESSED;
+        }
+    }
+    epstatus = KEEP_DTOG(USB->EPnR[0]);
+    if(rxflag) epstatus ^= USB_EPnR_STAT_TX; // start ZLP/data transmission
+    else epstatus &= ~USB_EPnR_STAT_TX; // or leave unchanged
+    // keep DTOGs, clear CTR_RX,TX, set RX VALID
+    USB->EPnR[0] = (epstatus & ~(USB_EPnR_CTR_RX|USB_EPnR_CTR_TX)) ^ USB_EPnR_STAT_RX;
+}
+
+static uint16_t lastaddr = LASTADDR_DEFAULT;
+/**
+ * Endpoint initialisation
+ * @param number - EP num (0...7)
+ * @param type - EP type (EP_TYPE_BULK, EP_TYPE_CONTROL, EP_TYPE_ISO, EP_TYPE_INTERRUPT)
+ * @param txsz - transmission buffer size @ USB/CAN buffer
+ * @param rxsz - reception buffer size @ USB/CAN buffer
+ * @param uint16_t (*func)(ep_t *ep) - EP handler function
+ * @return 0 if all OK
+ */
+int EP_Init(uint8_t number, uint8_t type, uint16_t txsz, uint16_t rxsz, void (*func)(ep_t ep)){
+    if(number >= STM32ENDPOINTS) return 4; // out of configured amount
+    if(txsz > USB_BTABLE_SIZE || rxsz > USB_BTABLE_SIZE) return 1; // buffer too large
+    if(lastaddr + txsz + rxsz >= USB_BTABLE_SIZE) return 2; // out of btable
+    USB->EPnR[number] = (type << 9) | (number & USB_EPnR_EA);
+    USB->EPnR[number] ^= USB_EPnR_STAT_RX | USB_EPnR_STAT_TX_1;
+    if(rxsz & 1 || rxsz > 512) return 3; // wrong rx buffer size
+    uint16_t countrx = 0;
+    if(rxsz < 64) countrx = rxsz / 2;
+    else{
+        if(rxsz & 0x1f) return 3; // should be multiple of 32
+        countrx = 31 + rxsz / 32;
+    }
+    USB_BTABLE->EP[number].USB_ADDR_TX = lastaddr;
+    endpoints[number].tx_buf = (uint16_t *)(USB_BTABLE_BASE + lastaddr*2);
+    endpoints[number].txbufsz = txsz;
+    lastaddr += txsz;
+    USB_BTABLE->EP[number].USB_COUNT_TX = 0;
+    USB_BTABLE->EP[number].USB_ADDR_RX = lastaddr;
+    endpoints[number].rx_buf = (uint16_t *)(USB_BTABLE_BASE + lastaddr*2);
+    lastaddr += rxsz;
+    USB_BTABLE->EP[number].USB_COUNT_RX = countrx << 10;
+    endpoints[number].func = func;
+    return 0;
+}
+
+// standard IRQ handler
+void usb_lp_can_rx0_isr(){
+    if(USB->ISTR & USB_ISTR_RESET){
+        usbON = 0;
+        // Reinit registers
+        USB->CNTR = USB_CNTR_RESETM | USB_CNTR_CTRM | USB_CNTR_SUSPM | USB_CNTR_WKUPM;
+        USB->ISTR = 0;
+        // Endpoint 0 - CONTROL
+        // ON USB LS size of EP0 may be 8 bytes, but on FS it should be 64 bytes!
+        lastaddr = LASTADDR_DEFAULT;
+        // clear address, leave only enable bit
+        USB->DADDR = USB_DADDR_EF;
+        USB_Dev.USB_Status = USB_STATE_DEFAULT;
+        USB->ISTR = ~USB_ISTR_RESET;
+        if(EP_Init(0, EP_TYPE_CONTROL, USB_EP0_BUFSZ, USB_EP0_BUFSZ, EP0_Handler)){
+            return;
+        }
+    }
+    if(USB->ISTR & USB_ISTR_CTR){
+        // EP number
+        uint8_t n = USB->ISTR & USB_ISTR_EPID;
+        // copy status register
+        uint16_t epstatus = USB->EPnR[n];
+        // copy received bytes amount
+        endpoints[n].rx_cnt = USB_BTABLE->EP[n].USB_COUNT_RX & 0x3FF; // low 10 bits is counter
+        // check direction
+        if(USB->ISTR & USB_ISTR_DIR){ // OUT interrupt - receive data, CTR_RX==1 (if CTR_TX == 1 - two pending transactions: receive following by transmit)
+            if(n == 0){ // control endpoint
+                if(epstatus & USB_EPnR_SETUP){ // setup packet -> copy data to conf_pack
+                    EP_Read(0, (uint16_t*)&setup_packet);
+                    ep0dbuflen = 0;
+                    // interrupt handler will be called later
+                }else if(epstatus & USB_EPnR_CTR_RX){ // data packet -> push received data to ep0databuf
+                    ep0dbuflen = endpoints[0].rx_cnt;
+                    EP_Read(0, (uint16_t*)&ep0databuf);
+                }
+            }
+        }
+        // call EP handler
+        if(endpoints[n].func) endpoints[n].func(endpoints[n]);
+    }
+    if(USB->ISTR & USB_ISTR_SUSP){ // suspend -> still no connection, may sleep
+        usbON = 0;
+        USB->CNTR |= USB_CNTR_FSUSP | USB_CNTR_LP_MODE;
+        USB->ISTR = ~USB_ISTR_SUSP;
+    }
+    if(USB->ISTR & USB_ISTR_WKUP){ // wakeup
+        USB->CNTR &= ~(USB_CNTR_FSUSP | USB_CNTR_LP_MODE); // clear suspend flags
+        USB->ISTR = ~USB_ISTR_WKUP;
+    }
+}
+
+/**
+ * Write data to EP buffer (called from IRQ handler)
+ * @param number - EP number
+ * @param *buf - array with data
+ * @param size - its size
+ */
+void EP_WriteIRQ(uint8_t number, const uint8_t *buf, uint16_t size){
+    uint8_t i;
+    if(size > endpoints[number].txbufsz) size = endpoints[number].txbufsz;
+    uint16_t N2 = (size + 1) >> 1;
+    // the buffer is 16-bit, so we should copy data as it would be uint16_t
+    uint16_t *buf16 = (uint16_t *)buf;
+    uint32_t *out = (uint32_t *)endpoints[number].tx_buf;
+    for(i = 0; i < N2; ++i, ++out){
+        *out = buf16[i];
+    }
+    USB_BTABLE->EP[number].USB_COUNT_TX = size;
+}
+
+/**
+ * Write data to EP buffer (called outside IRQ handler)
+ * @param number - EP number
+ * @param *buf - array with data
+ * @param size - its size
+ */
+void EP_Write(uint8_t number, const uint8_t *buf, uint16_t size){
+    EP_WriteIRQ(number, buf, size);
+    uint16_t status = KEEP_DTOG(USB->EPnR[number]);
+    // keep DTOGs, clear CTR_TX & set TX VALID to start transmission
+    USB->EPnR[number] = (status & ~(USB_EPnR_CTR_TX)) ^ USB_EPnR_STAT_TX;
+}
+
+/*
+ * Copy data from EP buffer into user buffer area
+ * @param *buf - user array for data
+ * @return amount of data read
+ */
+int EP_Read(uint8_t number, uint16_t *buf){
+    int sz = endpoints[number].rx_cnt;
+    if(!sz) return 0;
+    endpoints[number].rx_cnt = 0;
+    int n = (sz + 1) >> 1;
+    uint32_t *in = (uint32_t *)endpoints[number].rx_buf;
+    if(n){
+        for(int i = 0; i < n; ++i, ++in)
+            buf[i] = *(uint16_t*)in;
+    }
+    return sz;
+}
+

F1:F103/DS18/usb_lib.h

@@ -0,0 +1,184 @@
+/*
+ * This file is part of the DS18 project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#ifndef __USB_LIB_H__
+#define __USB_LIB_H__
+
+#include <wchar.h>
+#include "usb_defs.h"
+
+#define EP0DATABUF_SIZE                 (64)
+#define LASTADDR_DEFAULT                (STM32ENDPOINTS * 8)
+
+// bmRequestType & 0x7f
+#define STANDARD_DEVICE_REQUEST_TYPE    0
+#define STANDARD_ENDPOINT_REQUEST_TYPE  2
+#define VENDOR_REQUEST_TYPE             0x40
+#define CONTROL_REQUEST_TYPE            0x21
+// bRequest, standard; for bmRequestType == 0x80
+#define GET_STATUS                      0x00
+#define GET_DESCRIPTOR                  0x06
+#define GET_CONFIGURATION               0x08
+// for bmRequestType == 0
+#define CLEAR_FEATURE                   0x01
+#define SET_FEATURE                     0x03    // unused
+#define SET_ADDRESS                     0x05
+#define SET_DESCRIPTOR                  0x07    // unused
+#define SET_CONFIGURATION               0x09
+// for bmRequestType == 0x81, 1 or 0xB2
+#define GET_INTERFACE                   0x0A    // unused
+#define SET_INTERFACE                   0x0B    // unused
+#define SYNC_FRAME                      0x0C    // unused
+#define VENDOR_REQUEST                  0x01    // unused
+
+// Class-Specific Control Requests
+#define SEND_ENCAPSULATED_COMMAND       0x00    // unused
+#define GET_ENCAPSULATED_RESPONSE       0x01    // unused
+#define SET_COMM_FEATURE                0x02    // unused
+#define GET_COMM_FEATURE                0x03    // unused
+#define CLEAR_COMM_FEATURE              0x04    // unused
+#define SET_LINE_CODING                 0x20
+#define GET_LINE_CODING                 0x21
+#define SET_CONTROL_LINE_STATE          0x22
+#define SEND_BREAK                      0x23
+
+// control line states
+#define CONTROL_DTR                     0x01
+#define CONTROL_RTS                     0x02
+
+// wValue
+#define DEVICE_DESCRIPTOR               0x100
+#define CONFIGURATION_DESCRIPTOR        0x200
+#define STRING_LANG_DESCRIPTOR          0x300
+#define STRING_MAN_DESCRIPTOR           0x301
+#define STRING_PROD_DESCRIPTOR          0x302
+#define STRING_SN_DESCRIPTOR            0x303
+#define DEVICE_QUALIFIER_DESCRIPTOR     0x600
+
+#define RX_FLAG(epstat)                 (epstat & USB_EPnR_CTR_RX)
+#define TX_FLAG(epstat)                 (epstat & USB_EPnR_CTR_TX)
+#define SETUP_FLAG(epstat)              (epstat & USB_EPnR_SETUP)
+
+// EPnR bits manipulation
+#define KEEP_DTOG_STAT(EPnR)            (EPnR & ~(USB_EPnR_STAT_RX|USB_EPnR_STAT_TX|USB_EPnR_DTOG_RX|USB_EPnR_DTOG_TX))
+#define KEEP_DTOG(EPnR)                 (EPnR & ~(USB_EPnR_DTOG_RX|USB_EPnR_DTOG_TX))
+
+// USB state: uninitialized, addressed, ready for use
+typedef enum{
+    USB_STATE_DEFAULT,
+    USB_STATE_ADDRESSED,
+    USB_STATE_CONFIGURED,
+    USB_STATE_CONNECTED
+} USB_state;
+
+// EP types
+#define EP_TYPE_BULK                    0x00
+#define EP_TYPE_CONTROL                 0x01
+#define EP_TYPE_ISO                     0x02
+#define EP_TYPE_INTERRUPT               0x03
+
+#define LANG_US (uint16_t)0x0409
+
+#define _USB_STRING_(name, str)                  \
+static const struct name \
+{                          \
+        uint8_t  bLength;                       \
+        uint8_t  bDescriptorType;               \
+        uint16_t bString[(sizeof(str) - 2) / 2]; \
+    \
+} \
+name = {sizeof(name), 0x03, str}
+
+#define _USB_LANG_ID_(name, lng_id)     \
+    \
+static const struct name \
+{         \
+        uint8_t  bLength;         \
+        uint8_t  bDescriptorType; \
+        uint16_t bString;         \
+    \
+} \
+name = {0x04, 0x03, lng_id}
+#define STRING_LANG_DESCRIPTOR_SIZE_BYTE    (4)
+
+// EP0 configuration packet
+typedef struct {
+    uint8_t bmRequestType;
+    uint8_t bRequest;
+    uint16_t wValue;
+    uint16_t wIndex;
+    uint16_t wLength;
+} config_pack_t;
+
+// endpoints state
+typedef struct{
+    uint16_t *tx_buf;           // transmission buffer address
+    uint16_t txbufsz;           // transmission buffer size
+    uint16_t *rx_buf;           // reception buffer address
+    void (*func)();             // endpoint action function
+    unsigned rx_cnt  : 10;      // received data counter
+} ep_t;
+
+// USB status & its address
+typedef struct {
+    uint8_t  USB_Status;
+    uint16_t USB_Addr;
+}usb_dev_t;
+
+typedef struct {
+    uint32_t dwDTERate;
+    uint8_t bCharFormat;
+    #define USB_CDC_1_STOP_BITS   0
+    #define USB_CDC_1_5_STOP_BITS 1
+    #define USB_CDC_2_STOP_BITS   2
+    uint8_t bParityType;
+    #define USB_CDC_NO_PARITY     0
+    #define USB_CDC_ODD_PARITY    1
+    #define USB_CDC_EVEN_PARITY   2
+    #define USB_CDC_MARK_PARITY   3
+    #define USB_CDC_SPACE_PARITY  4
+    uint8_t bDataBits;
+} __attribute__ ((packed)) usb_LineCoding;
+
+typedef struct {
+    uint8_t   bmRequestType;
+    uint8_t   bNotificationType;
+    uint16_t  wValue;
+    uint16_t  wIndex;
+    uint16_t  wLength;
+} __attribute__ ((packed)) usb_cdc_notification;
+
+extern ep_t endpoints[];
+extern usb_dev_t USB_Dev;
+extern uint8_t usbON;
+
+void USB_Init();
+void USB_ResetState();
+int EP_Init(uint8_t number, uint8_t type, uint16_t txsz, uint16_t rxsz, void (*func)());
+void EP_WriteIRQ(uint8_t number, const uint8_t *buf, uint16_t size);
+void EP_Write(uint8_t number, const uint8_t *buf, uint16_t size);
+int EP_Read(uint8_t number, uint16_t *buf);
+usb_LineCoding getLineCoding();
+
+void linecoding_handler(usb_LineCoding *lc);
+void clstate_handler(uint16_t val);
+void break_handler();
+void vendor_handler(config_pack_t *packet);
+
+#endif // __USB_LIB_H__

F1:F103/F1_testbrd/Makefile

@@ -0,0 +1,139 @@
+BINARY		= pl2303
+BOOTPORT	?= /dev/ttyUSB0
+BOOTSPEED	?= 115200
+# MCU FAMILY
+FAMILY		?= F1
+# MCU code
+MCU			?= F103x8
+# density (stm32f10x.h, lines 70-84)
+DENSITY 	?= MD
+# change this linking script depending on particular MCU model,
+LDSCRIPT	?= stm32f103x8.ld
+# debug
+#DEFS		= -DEBUG
+
+INDEPENDENT_HEADERS=
+
+FP_FLAGS	?= -msoft-float -mfloat-abi=soft
+ASM_FLAGS	?= -mthumb -mcpu=cortex-m3 -mfix-cortex-m3-ldrd
+ARCH_FLAGS	= $(ASM_FLAGS) $(FP_FLAGS)
+
+###############################################################################
+# Executables
+#PREFIX		?= arm-none-eabi
+# gcc from arm web site 
+PREFIX		?= /opt/bin/arm-none-eabi
+TOOLCHLIB	?= /opt/arm-none-eabi/lib
+RM			:= rm -f
+RMDIR		:= rmdir
+CC			:= $(PREFIX)-gcc
+# don't replace ld with gcc: the binary size would be much greater!!
+LD			:= $(PREFIX)-ld
+AR			:= $(PREFIX)-ar
+AS			:= $(PREFIX)-as
+SIZE 		:= $(PREFIX)-size
+OBJCOPY		:= $(PREFIX)-objcopy
+OBJDUMP		:= $(PREFIX)-objdump
+GDB			:= $(PREFIX)-gdb
+STFLASH		:= $(shell which st-flash)
+STBOOT		:= $(shell which stm32flash)
+DFUUTIL		:= $(shell which dfu-util)
+
+###############################################################################
+# Source files
+OBJDIR 		= mk
+SRC			:= $(wildcard *.c)
+OBJS		:= $(addprefix $(OBJDIR)/, $(SRC:%.c=%.o))
+STARTUP		= $(OBJDIR)/startup.o
+OBJS 		+= $(STARTUP)
+# dependencies: we need them to recompile files if their headers-dependencies changed
+DEPS		:= $(OBJS:.o=.d)
+
+INC_DIR ?= ../inc
+
+INCLUDE 	:= -I$(INC_DIR)/Fx -I$(INC_DIR)/cm
+LIB_DIR		:= $(INC_DIR)/ld
+
+###############################################################################
+# C flags
+CFLAGS		+= -O2 -g -D__thumb2__=1 -MD
+CFLAGS		+= -Wall -Werror -Wextra -Wshadow 
+CFLAGS		+= -fno-common -ffunction-sections -fdata-sections -fno-stack-protector
+CFLAGS		+=  $(ARCH_FLAGS)
+
+###############################################################################
+# Linker flags
+LDFLAGS		+= -nostartfiles --static -nostdlibs 
+LDFLAGS		+= -L$(LIB_DIR) -L$(TOOLCHLIB)
+LDFLAGS		+= -T$(LDSCRIPT)
+
+###############################################################################
+# Used libraries
+LDLIBS		+=  -lc $(shell $(CC) $(CFLAGS) -print-libgcc-file-name)
+
+DEFS		+= -DSTM32$(FAMILY) -DSTM32$(MCU) -DSTM32F10X_$(DENSITY)
+
+ELF		:= $(OBJDIR)/$(BINARY).elf
+LIST	:= $(OBJDIR)/$(BINARY).list
+BIN		:= $(BINARY).bin
+HEX		:= $(BINARY).hex
+
+all: bin list size
+
+elf: $(ELF)
+bin: $(BIN)
+hex: $(HEX)
+list: $(LIST)
+
+ifneq ($(MAKECMDGOALS),clean)
+-include $(DEPS)
+endif
+
+$(OBJDIR):
+	mkdir $(OBJDIR)
+
+$(STARTUP): $(INC_DIR)/startup/vector.c
+	$(CC) $(CFLAGS) $(DEFS) $(INCLUDE) -o $@ -c $<
+
+$(OBJDIR)/%.o: %.c
+	@echo "  CC      $<"
+	$(CC) $(CFLAGS) $(DEFS) $(INCLUDE) -o $@ -c $<
+
+$(BIN): $(ELF)
+	@echo "  OBJCOPY $(BIN)"
+	$(OBJCOPY) -Obinary $(ELF) $(BIN)
+
+$(HEX): $(ELF)
+	@echo "  OBJCOPY $(HEX)"
+	$(OBJCOPY) -Oihex $(ELF) $(HEX)
+
+$(LIST): $(ELF)
+	@echo "  OBJDUMP $(LIST)"
+	$(OBJDUMP) -S $(ELF) > $(LIST)
+
+$(ELF): $(OBJDIR) $(OBJS)
+	@echo "  LD      $(ELF)"
+	$(LD) $(LDFLAGS) $(OBJS) $(LDLIBS) -o $(ELF)
+
+size: $(ELF)
+	$(SIZE) $(ELF)    
+
+clean:
+	@echo "  CLEAN"
+	$(RM) $(OBJS) $(DEPS) $(ELF) $(HEX) $(LIST)
+	@rmdir $(OBJDIR) 2>/dev/null || true
+
+
+flash: $(BIN)
+	@echo "  FLASH  $(BIN)"
+	$(STFLASH) write $(BIN) 0x8000000
+
+boot: $(BIN)
+	@echo "  LOAD $(BIN) through bootloader"
+	$(STBOOT) -b$(BOOTSPEED) $(BOOTPORT) -w $(BIN)
+
+dfuboot: $(BIN)
+	@echo "  LOAD  $(BIN) THROUGH DFU"
+	$(DFUUTIL) -a0 -D $(BIN) -s 0x08000000
+
+.PHONY: clean flash boot

F1:F103/F1_testbrd/Readme.md

@@ -0,0 +1 @@
+Simple test for STM32F103, blinking PA0/PA1, two user buttons (PA14 and PA15) and USB (PL2303 emulator) <> USART1 echo.

F1:F103/F1_testbrd/adc.c

@@ -0,0 +1,70 @@
+/*
+ * This file is part of the Chiller project.
+ * Copyright 2018 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "adc.h"
+
+/**
+ * @brief ADC_array - array for ADC channels with median filtering:
+ * 0 - Rvar
+ * 1 - internal Tsens
+ * 2 - Vref
+ */
+uint16_t ADC_array[NUMBER_OF_ADC_CHANNELS*9];
+
+/**
+ * @brief getADCval - calculate median value for `nch` channel
+ * @param nch - number of channel
+ * @return
+ */
+uint16_t getADCval(int nch){
+    int i, addr = nch;
+    register uint16_t temp;
+#define PIX_SORT(a,b) { if ((a)>(b)) PIX_SWAP((a),(b)); }
+#define PIX_SWAP(a,b) { temp=(a);(a)=(b);(b)=temp; }
+    uint16_t p[9];
+    for(i = 0; i < 9; ++i, addr += NUMBER_OF_ADC_CHANNELS) // first we should prepare array for optmed
+        p[i] = ADC_array[addr];
+    PIX_SORT(p[1], p[2]) ; PIX_SORT(p[4], p[5]) ; PIX_SORT(p[7], p[8]) ;
+    PIX_SORT(p[0], p[1]) ; PIX_SORT(p[3], p[4]) ; PIX_SORT(p[6], p[7]) ;
+    PIX_SORT(p[1], p[2]) ; PIX_SORT(p[4], p[5]) ; PIX_SORT(p[7], p[8]) ;
+    PIX_SORT(p[0], p[3]) ; PIX_SORT(p[5], p[8]) ; PIX_SORT(p[4], p[7]) ;
+    PIX_SORT(p[3], p[6]) ; PIX_SORT(p[1], p[4]) ; PIX_SORT(p[2], p[5]) ;
+    PIX_SORT(p[4], p[7]) ; PIX_SORT(p[4], p[2]) ; PIX_SORT(p[6], p[4]) ;
+    PIX_SORT(p[4], p[2]) ;
+    return p[4];
+#undef PIX_SORT
+#undef PIX_SWAP
+}
+
+// return MCU temperature (degrees of celsius * 10)
+int32_t getMCUtemp(){
+    // Temp = (V25 - Vsense)/Avg_Slope + 25
+    // V_25 = 1.45V,  Slope = 4.3e-3
+    int32_t Vsense = getVdd() * getADCval(1);
+    int32_t temperature = 593920 - Vsense; // 593920 == 145*4096
+    temperature /= 172; // == /(4096*10*4.3e-3), 10 - to convert from *100 to *10
+    temperature += 250;
+    return(temperature);
+}
+
+// return Vdd * 100 (V)
+uint32_t getVdd(){
+    uint32_t vdd = 120 * 4096; // 1.2V
+    vdd /= getADCval(2);
+    return vdd;
+}

F1:F103/F1_testbrd/adc.h

@@ -0,0 +1,29 @@
+/*
+ * This file is part of the Chiller project.
+ * Copyright 2018 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef ADC_H
+#define ADC_H
+#include "stm32f1.h"
+
+#define NUMBER_OF_ADC_CHANNELS (3)
+
+extern uint16_t ADC_array[];
+int32_t getMCUtemp();
+uint32_t getVdd();
+uint16_t getADCval(int nch);
+
+#endif // ADC_H

F1:F103/F1_testbrd/hardware.c

@@ -0,0 +1,79 @@
+/*
+ *                                                                                                  geany_encoding=koi8-r
+ * hardware.c - hardware-dependent macros & functions
+ *
+ * Copyright 2018 Edward V. Emelianov <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ *
+ */
+
+#include "adc.h"
+#include "hardware.h"
+#include "usart.h"
+
+static inline void gpio_setup(){
+    // Enable clocks to the GPIO subsystems (PB for ADC), turn on AFIO clocking to disable SWD/JTAG
+    RCC->APB2ENR |= RCC_APB2ENR_IOPAEN | RCC_APB2ENR_IOPBEN | RCC_APB2ENR_AFIOEN;
+    // turn off SWJ/JTAG
+    AFIO->MAPR = AFIO_MAPR_SWJ_CFG_DISABLE;
+    // turn off USB pullup
+    GPIOA->ODR = (1<<13)|(1<<14)|(1<<15); // turn off usb pullup & turn on pullups for buttons
+    // Set leds (PA0/PA4) as opendrain output
+    GPIOA->CRL = CRL(0, CNF_ODOUTPUT|MODE_SLOW) | CRL(4, CNF_ODOUTPUT|MODE_SLOW);
+    // Set buttons (PA14/15) as inputs with weak pullups, USB pullup (PA13) - opendrain output
+    GPIOA->CRH = CRH(13, CNF_ODOUTPUT|MODE_SLOW) | CRH(14, CNF_PUDINPUT|MODE_INPUT)
+                 | CRH(15, CNF_PUDINPUT|MODE_INPUT);
+}
+
+static inline void adc_setup(){
+    GPIOB->CRL |= CRL(0, CNF_ANALOG|MODE_INPUT);
+    uint32_t ctr = 0;
+    // Enable clocking
+    RCC->APB2ENR |= RCC_APB2ENR_ADC1EN;
+    RCC->CFGR &= ~(RCC_CFGR_ADCPRE);
+    RCC->CFGR |= RCC_CFGR_ADCPRE_DIV8; // ADC clock = RCC / 8
+    // sampling time - 239.5 cycles for channels 8, 16 and 17
+    ADC1->SMPR2 = ADC_SMPR2_SMP8;
+    ADC1->SMPR1 = ADC_SMPR1_SMP16 | ADC_SMPR1_SMP17;
+    // we have three conversions in group -> ADC1->SQR1[L] = 2, order: 8->16->17
+    ADC1->SQR3 = 8 | (16<<5) | (17<<10);
+    ADC1->SQR1 = ADC_SQR1_L_1;
+    ADC1->CR1 |= ADC_CR1_SCAN; // scan mode
+    // DMA configuration
+    RCC->AHBENR |= RCC_AHBENR_DMA1EN;
+    DMA1_Channel1->CPAR = (uint32_t) (&(ADC1->DR));
+    DMA1_Channel1->CMAR = (uint32_t)(ADC_array);
+    DMA1_Channel1->CNDTR = NUMBER_OF_ADC_CHANNELS * 9;
+    DMA1_Channel1->CCR |= DMA_CCR_MINC | DMA_CCR_MSIZE_0 | DMA_CCR_PSIZE_0
+                          | DMA_CCR_CIRC | DMA_CCR_PL | DMA_CCR_EN;
+    // continuous mode & DMA; enable vref & Tsens; wake up ADC
+    ADC1->CR2 |= ADC_CR2_DMA | ADC_CR2_TSVREFE | ADC_CR2_CONT | ADC_CR2_ADON;
+    // wait for Tstab - at least 1us
+    while(++ctr < 0xff) nop();
+    // calibration
+    ADC1->CR2 |= ADC_CR2_RSTCAL;
+    ctr = 0; while((ADC1->CR2 & ADC_CR2_RSTCAL) && ++ctr < 0xfffff);
+    ADC1->CR2 |= ADC_CR2_CAL;
+    ctr = 0; while((ADC1->CR2 & ADC_CR2_CAL) && ++ctr < 0xfffff);
+    // turn ON ADC
+    ADC1->CR2 |= ADC_CR2_ADON;
+}
+
+void hw_setup(){
+    gpio_setup();
+    adc_setup();
+}

F1:F103/F1_testbrd/hardware.h

@@ -0,0 +1,53 @@
+/*
+ *                                                                                                  geany_encoding=koi8-r
+ * hardware.h
+ *
+ * Copyright 2018 Edward V. Emelianov <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ *
+ */
+#pragma once
+#ifndef __HARDWARE_H__
+#define __HARDWARE_H__
+
+#include "stm32f1.h"
+
+// LEDS: 0 - PA0, 1 - PA4
+// LED0 - blinking each second
+#define LED0_port   GPIOA
+#define LED0_pin    (1<<0)
+// LED1 - PWM
+#define LED1_port   GPIOA
+#define LED1_pin    (1<<4)
+
+// Buttons' state: PA14 (1)/PA15 (0)
+#define GET_BTN0()  ((GPIOA->IDR & (1<<15)) ? 0 : 1)
+#define GET_BTN1()  ((GPIOA->IDR & (1<<14)) ? 0 : 1)
+
+// USB pullup (not used in STM32F0x2!) - PA13
+#define USBPU_port  GPIOA
+#define USBPU_pin   (1<<13)
+#define USBPU_ON()  pin_clear(USBPU_port, USBPU_pin)
+#define USBPU_OFF() pin_set(USBPU_port, USBPU_pin)
+
+#define LED_blink(x)    pin_toggle(x ## _port, x ## _pin)
+#define LED_on(x)       pin_clear(x ## _port, x ## _pin)
+#define LED_off(x)      pin_set(x ## _port, x ## _pin)
+
+void hw_setup();
+
+#endif // __HARDWARE_H__

F1:F103/F1_testbrd/main.c

@@ -0,0 +1,221 @@
+/*
+ * main.c
+ *
+ * Copyright 2017 Edward V. Emelianoff <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+
+#include "adc.h"
+#include "hardware.h"
+#include "usart.h"
+#include "usb.h"
+#include "usb_lib.h"
+
+volatile uint32_t Tms = 0;
+
+/* Called when systick fires */
+void sys_tick_handler(void){
+    ++Tms;
+}
+
+void iwdg_setup(){
+    uint32_t tmout = 16000000;
+    /* Enable the peripheral clock RTC */
+    /* (1) Enable the LSI (40kHz) */
+    /* (2) Wait while it is not ready */
+    RCC->CSR |= RCC_CSR_LSION; /* (1) */
+    while((RCC->CSR & RCC_CSR_LSIRDY) != RCC_CSR_LSIRDY){if(--tmout == 0) break;} /* (2) */
+    /* Configure IWDG */
+    /* (1) Activate IWDG (not needed if done in option bytes) */
+    /* (2) Enable write access to IWDG registers */
+    /* (3) Set prescaler by 64 (1.6ms for each tick) */
+    /* (4) Set reload value to have a rollover each 2s */
+    /* (5) Check if flags are reset */
+    /* (6) Refresh counter */
+    IWDG->KR = IWDG_START; /* (1) */
+    IWDG->KR = IWDG_WRITE_ACCESS; /* (2) */
+    IWDG->PR = IWDG_PR_PR_1; /* (3) */
+    IWDG->RLR = 1250; /* (4) */
+    tmout = 16000000;
+    while(IWDG->SR){if(--tmout == 0) break;} /* (5) */
+    IWDG->KR = IWDG_REFRESH; /* (6) */
+}
+
+#define USND(str)  do{USB_send((uint8_t*)str, sizeof(str)-1);}while(0)
+char *parse_cmd(char *buf){
+    static char btns[] = "BTN0=0, BTN1=0\n";
+    if(buf[1] != '\n') return buf;
+    switch(*buf){
+        case '0':
+            pin_set(GPIOA, 1<<4);
+        break;
+        case '1':
+            pin_clear(GPIOA, 1<<4);
+        break;
+        case 'b':
+            btns[5] = GET_BTN0() + '0';
+            btns[13] = GET_BTN1() + '0';
+            return btns;
+        break;
+        case 'p':
+            pin_toggle(USBPU_port, USBPU_pin);
+            SEND("USB pullup is ");
+            if(pin_read(USBPU_port, USBPU_pin)) SEND("off");
+            else SEND("on");
+            newline();
+        break;
+        case 'A':
+            return u2str(getADCval(0));
+        break;
+        case 'L':
+            USND("Very long test string for USB (it's length is more than 64 bytes).\n"
+                     "This is another part of the string! Can you see all of this?\n");
+            return "Long test sent\n";
+        break;
+        case 'R':
+            USND("Soft reset\n");
+            SEND("Soft reset\n");
+            NVIC_SystemReset();
+        break;
+        case 'S':
+            USND("Test string for USB\n");
+            return "Short test sent\n";
+        break;
+        case 'T':
+            return u2str(getMCUtemp());
+        break;
+        case 'V':
+            return u2str(getVdd());
+        break;
+        case 'W':
+            USND("Wait for reboot\n");
+            SEND("Wait for reboot\n");
+            while(1){nop();};
+        break;
+        default: // help
+            return
+            "0/1 - turn on/off LED1\n"
+            "'b' - get buttons's state\n"
+            "'p' - toggle USB pullup\n"
+            "'A' - get ADC8 value\n"
+            "'L' - send long string over USB\n"
+            "'R' - software reset\n"
+            "'S' - send short string over USB\n"
+            "'T' - MCU temperature\n"
+            "'V' - Vdd\n"
+            "'W' - test watchdog\n"
+            ;
+        break;
+    }
+    return NULL;
+}
+
+// usb getline
+char *get_USB(){
+    static char tmpbuf[512], *curptr = tmpbuf;
+    static int rest = 511;
+    int x = USB_receive((uint8_t*)curptr);
+    curptr[x] = 0;
+    if(!x) return NULL;
+    if(curptr[x-1] == '\n'){
+        curptr = tmpbuf;
+        rest = 511;
+        return tmpbuf;
+    }
+    curptr += x; rest -= x;
+    if(rest <= 0){ // buffer overflow
+        SEND("USB buffer overflow!\n");
+        curptr = tmpbuf;
+        rest = 511;
+    }
+    return NULL;
+}
+
+
+//int8_t dump = 0;
+int main(void){
+    uint32_t lastT = 0, lastB = 0, LEDperiod = 499;
+    sysreset();
+    StartHSE();
+    hw_setup();
+    usart_setup();
+    SysTick_Config(72000);
+
+    SEND("Hello! I'm ready.\n");
+
+    if(RCC->CSR & RCC_CSR_IWDGRSTF){ // watchdog reset occured
+        SEND("WDGRESET=1\n");
+    }
+    if(RCC->CSR & RCC_CSR_SFTRSTF){ // software reset occured
+        SEND("SOFTRESET=1\n");
+    }
+    RCC->CSR |= RCC_CSR_RMVF; // remove reset flags
+
+    USBPU_OFF();
+    USB_setup();
+    iwdg_setup();
+    USBPU_ON();
+
+    while (1){
+        IWDG->KR = IWDG_REFRESH; // refresh watchdog
+        if(lastT > Tms || Tms - lastT > LEDperiod){
+            LED_blink(LED0);
+            lastT = Tms;
+            transmit_tbuf(); // non-blocking transmission of data from UART buffer every 0.5s
+        }
+        usb_proc();
+        int r = 0;
+        char *txt, *ans;
+        if((txt = get_USB())){
+            ans = parse_cmd(txt);
+            SEND("Received data over USB:\n");
+            SEND(txt);
+            newline();
+            if(ans){
+                uint16_t l = 0; char *p = ans;
+                while(*p++) l++;
+                USB_send((uint8_t*)ans, l);
+            }
+        }
+        if(usartrx()){ // usart1 received data, store in in buffer
+            r = usart_getline(&txt);
+            if(r){
+                txt[r] = 0;
+                ans = parse_cmd(txt);
+                if(ans){
+                    usart_send(ans);
+                    transmit_tbuf();
+                }
+            }
+        }
+        // check buttons - each 50ms (increase / decrease LED blinking period by 10)
+        if(Tms - lastB > 49){
+            lastB = Tms;
+            uint8_t btn0 = GET_BTN0(), btn1 = GET_BTN1();
+            // both: set to default
+            if(btn0 && btn1){
+                LEDperiod = 499;
+            }else if(btn0){
+                if(LEDperiod < 1989) LEDperiod += 10;
+            }else if(btn1){
+                if(LEDperiod > 29) LEDperiod -= 10;
+            }
+        }
+    }
+    return 0;
+}
+

F1:F103/F1_testbrd/usart.c

@@ -0,0 +1,251 @@
+/*
+ * usart.c
+ *
+ * Copyright 2018 Edward V. Emelianoff <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+#include "stm32f1.h"
+#include "usart.h"
+
+extern volatile uint32_t Tms;
+static volatile int idatalen[2] = {0,0}; // received data line length (including '\n')
+static volatile int odatalen[2] = {0,0};
+
+volatile int linerdy = 0,        // received data ready
+    dlen = 0,           // length of data (including '\n') in current buffer
+    bufovr = 0,         // input buffer overfull
+    txrdy = 1           // transmission done
+;
+
+
+int rbufno = 0, tbufno = 0; // current rbuf/tbuf numbers
+static char rbuf[2][UARTBUFSZI], tbuf[2][UARTBUFSZO]; // receive & transmit buffers
+static char *recvdata = NULL;
+
+/**
+ * return length of received data (without trailing zero)
+ */
+int usart_getline(char **line){
+    if(bufovr){
+        bufovr = 0;
+        linerdy = 0;
+        return 0;
+    }
+    *line = recvdata;
+    linerdy = 0;
+    return dlen;
+}
+
+// transmit current tbuf and swap buffers
+void transmit_tbuf(){
+    uint32_t tmout = 72000;
+    while(!txrdy){if(--tmout == 0) return;}; // wait for previos buffer transmission
+    register int l = odatalen[tbufno];
+    if(!l) return;
+    txrdy = 0;
+    odatalen[tbufno] = 0;
+    DMA1_Channel4->CCR &= ~DMA_CCR_EN;
+    DMA1_Channel4->CMAR = (uint32_t) tbuf[tbufno]; // mem
+    DMA1_Channel4->CNDTR = l;
+    DMA1_Channel4->CCR |= DMA_CCR_EN;
+    tbufno = !tbufno;
+}
+
+void usart_putchar(const char ch){
+    for(int i = 0; odatalen[tbufno] == UARTBUFSZO && i < 1024; ++i) transmit_tbuf();
+    tbuf[tbufno][odatalen[tbufno]++] = ch;
+}
+
+void usart_send(const char *str){
+    uint32_t x = 512;
+    while(*str && --x){
+        if(odatalen[tbufno] == UARTBUFSZO){
+            transmit_tbuf();
+            continue;
+        }
+        tbuf[tbufno][odatalen[tbufno]++] = *str++;
+    }
+}
+
+void newline(){
+    usart_putchar('\n');
+    transmit_tbuf();
+}
+
+
+/*
+ * USART speed: baudrate = Fck/(USARTDIV)
+ * USARTDIV stored in USART->BRR
+ *
+ * for 72MHz USARTDIV=72000/f(kboud); so for 115200 USARTDIV=72000/115.2=625 -> BRR=0x271
+ *         9600: BRR = 7500 (0x1D4C)
+ */
+
+void usart_setup(){
+    uint32_t tmout = 16000000;
+    // PA9 - Tx, PA10 - Rx
+    RCC->APB2ENR |= RCC_APB2ENR_IOPAEN | RCC_APB2ENR_USART1EN;
+    RCC->AHBENR |= RCC_AHBENR_DMA1EN;
+    GPIOA->CRH |= CRH(9, CNF_AFPP|MODE_NORMAL) | CRH(10, CNF_FLINPUT|MODE_INPUT);
+
+    // USART1 Tx DMA - Channel4 (Rx - channel 5)
+    DMA1_Channel4->CPAR = (uint32_t) &USART1->DR; // periph
+    DMA1_Channel4->CCR |= DMA_CCR_MINC | DMA_CCR_DIR | DMA_CCR_TCIE; // 8bit, mem++, mem->per, transcompl irq
+    // Tx CNDTR set @ each transmission due to data size
+    NVIC_SetPriority(DMA1_Channel4_IRQn, 3);
+    NVIC_EnableIRQ(DMA1_Channel4_IRQn);
+    NVIC_SetPriority(USART1_IRQn, 0);
+    // setup usart1
+    USART1->BRR = 72000000 / 115200;
+    USART1->CR1 = USART_CR1_TE | USART_CR1_RE | USART_CR1_UE; // 1start,8data,nstop; enable Rx,Tx,USART
+    while(!(USART1->SR & USART_SR_TC)){if(--tmout == 0) break;} // polling idle frame Transmission
+    USART1->SR = 0; // clear flags
+    USART1->CR1 |= USART_CR1_RXNEIE; // allow Rx IRQ
+    USART1->CR3 = USART_CR3_DMAT; // enable DMA Tx
+    NVIC_EnableIRQ(USART1_IRQn);
+}
+
+
+void usart1_isr(){
+    #ifdef CHECK_TMOUT
+    static uint32_t tmout = 0;
+    #endif
+    if(USART1->SR & USART_SR_RXNE){ // RX not emty - receive next char
+        #ifdef CHECK_TMOUT
+        if(tmout && Tms >= tmout){ // set overflow flag
+            bufovr = 1;
+            idatalen[rbufno] = 0;
+        }
+        tmout = Tms + TIMEOUT_MS;
+        if(!tmout) tmout = 1; // prevent 0
+        #endif
+        uint8_t rb = USART1->DR;
+        if(idatalen[rbufno] < UARTBUFSZI){ // put next char into buf
+            rbuf[rbufno][idatalen[rbufno]++] = rb;
+            if(rb == '\n'){ // got newline - line ready
+                linerdy = 1;
+                dlen = idatalen[rbufno];
+                recvdata = rbuf[rbufno];
+                // prepare other buffer
+                rbufno = !rbufno;
+                idatalen[rbufno] = 0;
+                #ifdef CHECK_TMOUT
+                // clear timeout at line end
+                tmout = 0;
+                #endif
+            }
+        }else{ // buffer overrun
+            bufovr = 1;
+            idatalen[rbufno] = 0;
+            #ifdef CHECK_TMOUT
+            tmout = 0;
+            #endif
+        }
+    }
+}
+
+// return string buffer with val
+char *u2str(uint32_t val){
+    static char bufa[11];
+    char bufb[10];
+    int l = 0, bpos = 0;
+    if(!val){
+        bufa[0] = '0';
+        l = 1;
+    }else{
+        while(val){
+            bufb[l++] = val % 10 + '0';
+            val /= 10;
+        }
+        int i;
+        bpos += l;
+        for(i = 0; i < l; ++i){
+            bufa[--bpos] = bufb[i];
+        }
+    }
+    bufa[l + bpos] = 0;
+    return bufa;
+}
+// print 32bit unsigned int
+void printu(uint32_t val){
+    usart_send(u2str(val));
+}
+
+// print 32bit unsigned int as hex
+void printuhex(uint32_t val){
+    usart_send("0x");
+    uint8_t *ptr = (uint8_t*)&val + 3;
+    int i, j;
+    for(i = 0; i < 4; ++i, --ptr){
+        for(j = 1; j > -1; --j){
+            register uint8_t half = (*ptr >> (4*j)) & 0x0f;
+            if(half < 10) usart_putchar(half + '0');
+            else usart_putchar(half - 10 + 'a');
+        }
+    }
+}
+
+// dump memory buffer
+void hexdump(uint8_t *arr, uint16_t len){
+    for(uint16_t l = 0; l < len; ++l, ++arr){
+        for(int16_t j = 1; j > -1; --j){
+            register uint8_t half = (*arr >> (4*j)) & 0x0f;
+            if(half < 10) usart_putchar(half + '0');
+            else usart_putchar(half - 10 + 'a');
+        }
+        if(l % 16 == 15) usart_putchar('\n');
+        else if((l & 3) == 3) usart_putchar(' ');
+    }
+}
+
+// dump USB memory (uint16_t mapped as uint32_t); len - in uint16_t
+void hexdump16(uint16_t *arr, uint16_t len){
+    for(uint16_t l = 0; l < len; ++l, ++arr){
+        uint16_t x = arr[l];
+        for(int8_t i = 0; i < 2; ++i){
+            for(int16_t j = 1; j > -1; --j){
+                register uint8_t half = (x >> (4*j+8*i)) & 0x0f;
+                if(half < 10) usart_putchar(half + '0');
+                else usart_putchar(half - 10 + 'a');
+            }
+        }
+        if(l % 8 == 7) usart_putchar('\n');
+        else if(l & 1) usart_putchar(' ');
+    }
+}
+
+void hexdump32(uint32_t *arr, uint16_t len){
+    for(uint16_t l = 0; l < len; ++l, ++arr){
+        uint16_t x = (uint16_t)arr[l];
+        for(int8_t i = 0; i < 2; ++i){
+            for(int16_t j = 1; j > -1; --j){
+                register uint8_t half = (x >> (4*j+8*i)) & 0x0f;
+                if(half < 10) usart_putchar(half + '0');
+                else usart_putchar(half - 10 + 'a');
+            }
+        }
+        if(l % 8 == 7) usart_putchar('\n');
+        else if(l & 1) usart_putchar(' ');
+    }
+}
+
+void dma1_channel4_isr(){
+    if(DMA1->ISR & DMA_ISR_TCIF4){ // Tx
+        DMA1->IFCR = DMA_IFCR_CTCIF4; // clear TC flag
+        txrdy = 1;
+    }
+}

F1:F103/F1_testbrd/usart.h

@@ -0,0 +1,67 @@
+/*
+ * usart.h
+ *
+ * Copyright 2017 Edward V. Emelianoff <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ */
+#pragma once
+#ifndef __USART_H__
+#define __USART_H__
+
+#include <stdint.h>
+
+// input and output buffers size
+#define UARTBUFSZI  (32)
+#define UARTBUFSZO  (512)
+// timeout between data bytes
+#ifndef TIMEOUT_MS
+#define TIMEOUT_MS (1500)
+#endif
+
+// macro for static strings
+#define SEND(str) usart_send(str)
+
+#define STR_HELPER(s)   #s
+#define STR(s)          STR_HELPER(s)
+
+#ifdef EBUG
+#define MSG(str)  do{SEND(__FILE__ " (L" STR(__LINE__) "): " str);}while(0)
+#define DBG(str)  do{SEND(str); usart_putchar('\n'); }while(0)
+#else
+#define MSG(str)
+#define DBG(str)
+#endif
+
+#define usartrx()  (linerdy)
+#define usartovr() (bufovr)
+
+extern volatile int linerdy, bufovr, txrdy;
+
+void transmit_tbuf();
+void usart_setup();
+int usart_getline(char **line);
+void usart_send(const char *str);
+void newline();
+void usart_putchar(const char ch);
+char *u2str(uint32_t val);
+void printu(uint32_t val);
+void printuhex(uint32_t val);
+void hexdump(uint8_t *arr, uint16_t len);
+void hexdump16(uint16_t *arr, uint16_t len);
+void hexdump32(uint32_t *arr, uint16_t len);
+
+#endif // __USART_H__

F1:F103/F1_testbrd/usb.c

@@ -0,0 +1,167 @@
+/*
+ *                                                                                                  geany_encoding=koi8-r
+ * usb.c - base functions for different USB types
+ *
+ * Copyright 2018 Edward V. Emelianov <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ *
+ */
+#include "usart.h"
+#include "usb.h"
+#include "usb_lib.h"
+
+static volatile uint8_t tx_succesfull = 1;
+static volatile uint8_t rxNE = 0;
+
+// interrupt IN handler (never used?)
+static void EP1_Handler(){
+    uint16_t epstatus = KEEP_DTOG(USB->EPnR[1]);
+    if(RX_FLAG(epstatus)) epstatus = (epstatus & ~USB_EPnR_STAT_TX) ^ USB_EPnR_STAT_RX; // set valid RX
+    else epstatus = epstatus & ~(USB_EPnR_STAT_TX|USB_EPnR_STAT_RX);
+    // clear CTR
+    epstatus = (epstatus & ~(USB_EPnR_CTR_RX|USB_EPnR_CTR_TX));
+    USB->EPnR[1] = epstatus;
+}
+
+// data IN/OUT handlers
+static void transmit_Handler(){ // EP3IN
+    tx_succesfull = 1;
+    uint16_t epstatus = KEEP_DTOG_STAT(USB->EPnR[3]);
+    // clear CTR keep DTOGs & STATs
+    USB->EPnR[3] = (epstatus & ~(USB_EPnR_CTR_TX)); // clear TX ctr
+}
+
+static void receive_Handler(){ // EP2OUT
+    rxNE = 1;
+    uint16_t epstatus = KEEP_DTOG_STAT(USB->EPnR[2]);
+    USB->EPnR[2] = (epstatus & ~(USB_EPnR_CTR_RX)); // clear RX ctr
+    DBG("RXh");
+}
+
+void USB_setup(){
+    NVIC_DisableIRQ(USB_LP_CAN1_RX0_IRQn);
+    NVIC_DisableIRQ(USB_HP_CAN1_TX_IRQn);
+    RCC->APB1ENR |= RCC_APB1ENR_USBEN;
+    USB->CNTR   = USB_CNTR_FRES; // Force USB Reset
+    for(uint32_t ctr = 0; ctr < 72000; ++ctr) nop(); // wait >1ms
+    //uint32_t ctr = 0;
+    USB->CNTR   = 0;
+    USB->BTABLE = 0;
+    USB->DADDR  = 0;
+    USB->ISTR   = 0;
+    USB->CNTR   = USB_CNTR_RESETM | USB_CNTR_WKUPM; // allow only wakeup & reset interrupts
+    NVIC_EnableIRQ(USB_LP_CAN1_RX0_IRQn);
+}
+
+static int usbwr(const uint8_t *buf, uint16_t l){
+    uint32_t ctra = 1000000;
+    while(--ctra && tx_succesfull == 0){
+        IWDG->KR = IWDG_REFRESH;
+    }
+    tx_succesfull = 0;
+    EP_Write(3, buf, l);
+    ctra = 1000000;
+    while(--ctra && tx_succesfull == 0){
+        IWDG->KR = IWDG_REFRESH;
+    }
+    if(tx_succesfull == 0){usbON = 0; return 1;} // usb is OFF?
+    return 0;
+}
+
+static uint8_t usbbuff[USB_TXBUFSZ-1]; // temporary buffer (63 - to prevent need of ZLP)
+static uint8_t buflen = 0; // amount of symbols in usbbuff
+
+// send next up to 63 bytes of data in usbbuff
+static void send_next(){
+    if(!buflen || !tx_succesfull) return;
+    tx_succesfull = 0;
+    EP_Write(3, usbbuff, buflen);
+    buflen = 0;
+}
+
+// unblocking sending - just fill a buffer
+void USB_send(const uint8_t *buf, uint16_t len){
+    if(!usbON || !len) return;
+    if(len > USB_TXBUFSZ-1 - buflen){
+        usbwr(usbbuff, buflen);
+        buflen = 0;
+    }
+    if(len > USB_TXBUFSZ-1){
+        USB_send_blk(buf, len);
+        return;
+    }
+    while(len--) usbbuff[buflen++] = *buf++;
+}
+
+// blocking sending
+void USB_send_blk(const uint8_t *buf, uint16_t len){
+    if(!usbON || !len) return; // USB disconnected
+    if(buflen){
+        usbwr(usbbuff, buflen);
+        buflen = 0;
+    }
+    int needzlp = 0;
+    while(len){
+        if(len == USB_TXBUFSZ) needzlp = 1;
+        uint16_t s = (len > USB_TXBUFSZ) ? USB_TXBUFSZ : len;
+        if(usbwr(buf, s)) return;
+        len -= s;
+        buf += s;
+    }
+    if(needzlp){
+        usbwr(NULL, 0);
+    }
+}
+
+void usb_proc(){
+    switch(USB_Dev.USB_Status){
+        case USB_STATE_CONFIGURED:
+            // make new BULK endpoint
+            // Buffer have 1024 bytes, but last 256 we use for CAN bus (30.2 of RM: USB main features)
+            EP_Init(1, EP_TYPE_INTERRUPT, USB_EP1BUFSZ, 0, EP1_Handler); // IN1 - transmit
+            EP_Init(2, EP_TYPE_BULK, 0, USB_RXBUFSZ, receive_Handler); // OUT2 - receive data
+            EP_Init(3, EP_TYPE_BULK, USB_TXBUFSZ, 0, transmit_Handler); // IN3 - transmit data
+            USB_Dev.USB_Status = USB_STATE_CONNECTED;
+        break;
+        case USB_STATE_DEFAULT:
+        case USB_STATE_ADDRESSED:
+            if(usbON){
+                usbON = 0;
+            }
+        break;
+        default: // USB_STATE_CONNECTED - send next data portion
+            if(!usbON) return;
+            send_next();
+    }
+}
+
+/**
+ * @brief USB_receive
+ * @param buf (i) - buffer[64] for received data
+ * @return amount of received bytes
+ */
+uint8_t USB_receive(uint8_t *buf){
+    if(!usbON || !rxNE) return 0;
+    DBG("Get data");
+    SEND((char*)buf); newline();
+    uint8_t sz = EP_Read(2, (uint16_t*)buf);
+    uint16_t epstatus = KEEP_DTOG(USB->EPnR[2]);
+    // keep stat_tx & set ACK rx
+    USB->EPnR[2] = (epstatus & ~(USB_EPnR_STAT_TX)) ^ USB_EPnR_STAT_RX;
+    rxNE = 0;
+    return sz;
+}

F1:F103/F1_testbrd/usb.h

@@ -0,0 +1,37 @@
+/*
+ *                                                                                                  geany_encoding=koi8-r
+ * usb.h
+ *
+ * Copyright 2018 Edward V. Emelianov <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ *
+ */
+#pragma once
+#ifndef __USB_H__
+#define __USB_H__
+
+#include "hardware.h"
+
+#define BUFFSIZE   (64)
+
+void USB_setup();
+void usb_proc();
+void USB_send(const uint8_t *buf, uint16_t len);
+void USB_send_blk(const uint8_t *buf, uint16_t len);
+uint8_t USB_receive(uint8_t *buf);
+
+#endif // __USB_H__

F1:F103/F1_testbrd/usb_defs.h

@@ -0,0 +1,107 @@
+/*
+ *                                                                                                  geany_encoding=koi8-r
+ * usb_defs.h
+ *
+ * Copyright 2018 Edward V. Emelianov <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ *
+ */
+
+#pragma once
+#ifndef __USB_DEFS_H__
+#define __USB_DEFS_H__
+
+#include <stm32f1.h>
+
+// max endpoints number
+#define STM32ENDPOINTS          8
+/**
+ *                 Buffers size definition
+ **/
+#define USB_BTABLE_SIZE         512
+// first 64 bytes of USB_BTABLE are registers!
+//#define USB_EP0_BASEADDR        64
+// for USB FS EP0 buffers are from 8 to 64 bytes long (64 for PL2303)
+#define USB_EP0_BUFSZ           64
+// USB transmit buffer size (64 for PL2303)
+#define USB_TXBUFSZ             64
+// USB receive buffer size (64 for PL2303)
+#define USB_RXBUFSZ             64
+// EP1 - interrupt - buffer size
+#define USB_EP1BUFSZ            8
+
+#define USB_BTABLE_BASE         0x40006000
+#define USB_BASE                ((uint32_t)0x40005C00)
+#define USB                     ((USB_TypeDef *) USB_BASE)
+
+#ifdef USB_BTABLE
+#undef USB_BTABLE
+#endif
+#define USB_BTABLE              ((USB_BtableDef *)(USB_BTABLE_BASE))
+#define USB_ISTR_EPID           0x0000000F
+#define USB_FNR_LSOF_0          0x00000800
+#define USB_FNR_lSOF_1          0x00001000
+#define USB_LPMCSR_BESL_0       0x00000010
+#define USB_LPMCSR_BESL_1       0x00000020
+#define USB_LPMCSR_BESL_2       0x00000040
+#define USB_LPMCSR_BESL_3       0x00000080
+#define USB_EPnR_CTR_RX         0x00008000
+#define USB_EPnR_DTOG_RX        0x00004000
+#define USB_EPnR_STAT_RX        0x00003000
+#define USB_EPnR_STAT_RX_0      0x00001000
+#define USB_EPnR_STAT_RX_1      0x00002000
+#define USB_EPnR_SETUP          0x00000800
+#define USB_EPnR_EP_TYPE        0x00000600
+#define USB_EPnR_EP_TYPE_0      0x00000200
+#define USB_EPnR_EP_TYPE_1      0x00000400
+#define USB_EPnR_EP_KIND        0x00000100
+#define USB_EPnR_CTR_TX         0x00000080
+#define USB_EPnR_DTOG_TX        0x00000040
+#define USB_EPnR_STAT_TX        0x00000030
+#define USB_EPnR_STAT_TX_0      0x00000010
+#define USB_EPnR_STAT_TX_1      0x00000020
+#define USB_EPnR_EA             0x0000000F
+#define USB_COUNTn_RX_BLSIZE    0x00008000
+#define USB_COUNTn_NUM_BLOCK    0x00007C00
+#define USB_COUNTn_RX           0x0000003F
+
+#ifdef USB_TypeDef
+#define USB_TypeDef USB_TypeDef_custom
+#endif
+
+typedef struct {
+    __IO uint32_t EPnR[STM32ENDPOINTS];
+    __IO uint32_t RESERVED[STM32ENDPOINTS];
+    __IO uint32_t CNTR;
+    __IO uint32_t ISTR;
+    __IO uint32_t FNR;
+    __IO uint32_t DADDR;
+    __IO uint32_t BTABLE;
+} USB_TypeDef;
+
+typedef struct{
+    __IO uint32_t USB_ADDR_TX;
+    __IO uint32_t USB_COUNT_TX;
+    __IO uint32_t USB_ADDR_RX;
+    __IO uint32_t USB_COUNT_RX;
+} USB_EPDATA_TypeDef;
+
+typedef struct{
+    __IO USB_EPDATA_TypeDef EP[STM32ENDPOINTS];
+} USB_BtableDef;
+
+#endif // __USB_DEFS_H__

F1:F103/F1_testbrd/usb_lib.c

@@ -0,0 +1,482 @@
+/*
+ *                                                                                                  geany_encoding=koi8-r
+ * usb_lib.c
+ *
+ * Copyright 2018 Edward V. Emelianov <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ *
+ */
+
+#include <stdint.h>
+#include "usb_lib.h"
+
+ep_t endpoints[STM32ENDPOINTS];
+
+usb_dev_t USB_Dev;
+static usb_LineCoding lineCoding = {115200, 0, 0, 8};
+static config_pack_t setup_packet;
+static uint8_t ep0databuf[EP0DATABUF_SIZE];
+static uint8_t ep0dbuflen = 0;
+
+usb_LineCoding getLineCoding(){return lineCoding;}
+
+uint8_t usbON = 0; // device disconnected from terminal
+
+// definition of parts common for USB_DeviceDescriptor & USB_DeviceQualifierDescriptor
+#define bcdUSB_L        0x10
+#define bcdUSB_H        0x01
+#define bDeviceClass    0
+#define bDeviceSubClass 0
+#define bDeviceProtocol 0
+#define bNumConfigurations 1
+
+static const uint8_t USB_DeviceDescriptor[] = {
+        18,     // bLength
+        0x01,   // bDescriptorType - Device descriptor
+        bcdUSB_L,   // bcdUSB_L - 1.10
+        bcdUSB_H,   // bcdUSB_H
+        bDeviceClass,   // bDeviceClass - USB_COMM
+        bDeviceSubClass,   // bDeviceSubClass
+        bDeviceProtocol,   // bDeviceProtocol
+        USB_EP0_BUFSZ,   // bMaxPacketSize
+        0x7b,   // idVendor_L PL2303: VID=0x067b, PID=0x2303
+        0x06,   // idVendor_H
+        0x03,   // idProduct_L
+        0x23,   // idProduct_H
+        0x00,   // bcdDevice_Ver_L
+        0x03,   // bcdDevice_Ver_H
+        0x01,   // iManufacturer
+        0x02,   // iProduct
+        0x00,   // iSerialNumber
+        bNumConfigurations    // bNumConfigurations
+};
+
+static const uint8_t USB_DeviceQualifierDescriptor[] = {
+        10,     //bLength
+        0x06,   // bDescriptorType - Device qualifier
+        bcdUSB_L,   // bcdUSB_L
+        bcdUSB_H,   // bcdUSB_H
+        bDeviceClass,   // bDeviceClass
+        bDeviceSubClass,   // bDeviceSubClass
+        bDeviceProtocol,   // bDeviceProtocol
+        USB_EP0_BUFSZ,   // bMaxPacketSize0
+        bNumConfigurations,   // bNumConfigurations
+        0x00    // Reserved
+};
+
+static const uint8_t USB_ConfigDescriptor[] = {
+        /*Configuration Descriptor*/
+        0x09, /* bLength: Configuration Descriptor size */
+        0x02, /* bDescriptorType: Configuration */
+        39,   /* wTotalLength:no of returned bytes */
+        0x00,
+        0x01, /* bNumInterfaces: 1 interface */
+        0x01, /* bConfigurationValue: Configuration value */
+        0x00, /* iConfiguration: Index of string descriptor describing the configuration */
+        0xa0, /* bmAttributes - Bus powered, Remote wakeup */
+        0x32, /* MaxPower 100 mA */
+
+        /*---------------------------------------------------------------------------*/
+
+        /*Interface Descriptor */
+        0x09, /* bLength: Interface Descriptor size */
+        0x04, /* bDescriptorType: Interface */
+        0x00, /* bInterfaceNumber: Number of Interface */
+        0x00, /* bAlternateSetting: Alternate setting */
+        0x03, /* bNumEndpoints: 3 endpoints used */
+        0xff, /* bInterfaceClass */
+        0x00, /* bInterfaceSubClass */
+        0x00, /* bInterfaceProtocol */
+        0x00, /* iInterface: */
+///////////////////////////////////////////////////
+        /*Endpoint 1 Descriptor*/
+        0x07, /* bLength: Endpoint Descriptor size */
+        0x05, /* bDescriptorType: Endpoint */
+        0x81, /* bEndpointAddress IN1 */
+        0x03, /* bmAttributes: Interrupt */
+        0x0a, /* wMaxPacketSize LO: */
+        0x00, /* wMaxPacketSize HI: */
+        0x01, /* bInterval: */
+
+        /*Endpoint OUT2 Descriptor*/
+        0x07, /* bLength: Endpoint Descriptor size */
+        0x05, /* bDescriptorType: Endpoint */
+        0x02, /* bEndpointAddress: OUT2 */
+        0x02, /* bmAttributes: Bulk */
+        (USB_RXBUFSZ & 0xff), /* wMaxPacketSize: 64 */
+        (USB_RXBUFSZ >> 8),
+        0x00, /* bInterval: ignore for Bulk transfer */
+
+        /*Endpoint IN3 Descriptor*/
+        0x07, /* bLength: Endpoint Descriptor size */
+        0x05, /* bDescriptorType: Endpoint */
+        0x83, /* bEndpointAddress IN3 */
+        0x02, /* bmAttributes: Bulk */
+        (USB_TXBUFSZ & 0xff), /* wMaxPacketSize: 64 */
+        (USB_TXBUFSZ >> 8),
+        0x00, /* bInterval: ignore for Bulk transfer */
+};
+
+_USB_LANG_ID_(USB_StringLangDescriptor, LANG_US);
+// these descriptors are not used in PL2303 emulator!
+_USB_STRING_(USB_StringSerialDescriptor, u"0");
+_USB_STRING_(USB_StringManufacturingDescriptor, u"Prolific Technology Inc.");
+_USB_STRING_(USB_StringProdDescriptor, u"USB-Serial Controller");
+
+/*
+ * default handlers
+ */
+// SET_LINE_CODING
+void WEAK linecoding_handler(usb_LineCoding __attribute__((unused)) *lc){
+}
+
+// SET_CONTROL_LINE_STATE
+void WEAK clstate_handler(uint16_t __attribute__((unused)) val){
+}
+
+// SEND_BREAK
+void WEAK break_handler(){
+}
+
+// handler of vendor requests
+void WEAK vendor_handler(config_pack_t *packet){
+    if(packet->bmRequestType & 0x80){ // read
+        uint8_t c;
+        switch(packet->wValue){
+            case 0x8484:
+                c = 2;
+            break;
+            case 0x0080:
+                c = 1;
+            break;
+            case 0x8686:
+                c = 0xaa;
+            break;
+            default:
+                c = 0;
+        }
+        EP_WriteIRQ(0, &c, 1);
+    }else{ // write ZLP
+        EP_WriteIRQ(0, (uint8_t *)0, 0);
+    }
+}
+
+static void wr0(const uint8_t *buf, uint16_t size){
+    if(setup_packet.wLength < size) size = setup_packet.wLength; // shortened request
+    if(size < endpoints[0].txbufsz){
+        EP_WriteIRQ(0, buf, size);
+        return;
+    }
+    while(size){
+        uint16_t l = size;
+        if(l > endpoints[0].txbufsz) l = endpoints[0].txbufsz;
+        EP_WriteIRQ(0, buf, l);
+        buf += l;
+        size -= l;
+        uint8_t needzlp = (l == endpoints[0].txbufsz) ? 1 : 0;
+        if(size || needzlp){ // send last data buffer
+            uint16_t status = KEEP_DTOG(USB->EPnR[0]);
+            // keep DTOGs, clear CTR_RX,TX, set TX VALID, leave stat_Rx
+            USB->EPnR[0] = (status & ~(USB_EPnR_CTR_RX|USB_EPnR_CTR_TX|USB_EPnR_STAT_RX))
+                            ^ USB_EPnR_STAT_TX;
+            uint32_t ctr = 1000000;
+            while(--ctr && (USB->ISTR & USB_ISTR_CTR) == 0){IWDG->KR = IWDG_REFRESH;};
+            if((USB->ISTR & USB_ISTR_CTR) == 0){
+                return;
+            }
+            if(needzlp) EP_WriteIRQ(0, (uint8_t*)0, 0);
+        }
+    }
+}
+
+static inline void get_descriptor(){
+    switch(setup_packet.wValue){
+        case DEVICE_DESCRIPTOR:
+            wr0(USB_DeviceDescriptor, sizeof(USB_DeviceDescriptor));
+        break;
+        case CONFIGURATION_DESCRIPTOR:
+            wr0(USB_ConfigDescriptor, sizeof(USB_ConfigDescriptor));
+        break;
+        case STRING_LANG_DESCRIPTOR:
+            wr0((const uint8_t *)&USB_StringLangDescriptor, STRING_LANG_DESCRIPTOR_SIZE_BYTE);
+        break;
+        case STRING_MAN_DESCRIPTOR:
+            wr0((const uint8_t *)&USB_StringManufacturingDescriptor, USB_StringManufacturingDescriptor.bLength);
+        break;
+        case STRING_PROD_DESCRIPTOR:
+            wr0((const uint8_t *)&USB_StringProdDescriptor, USB_StringProdDescriptor.bLength);
+        break;
+        case STRING_SN_DESCRIPTOR:
+            wr0((const uint8_t *)&USB_StringSerialDescriptor, USB_StringSerialDescriptor.bLength);
+        break;
+        case DEVICE_QUALIFIER_DESCRIPTOR:
+            wr0(USB_DeviceQualifierDescriptor, USB_DeviceQualifierDescriptor[0]);
+        break;
+        default:
+        break;
+    }
+}
+
+static uint8_t configuration = 0; // reply for GET_CONFIGURATION (==1 if configured)
+static inline void std_d2h_req(){
+    uint16_t status = 0; // bus powered
+    switch(setup_packet.bRequest){
+        case GET_DESCRIPTOR:
+            get_descriptor();
+        break;
+        case GET_STATUS:
+            EP_WriteIRQ(0, (uint8_t *)&status, 2); // send status: Bus Powered
+        break;
+        case GET_CONFIGURATION:
+            EP_WriteIRQ(0, &configuration, 1);
+        break;
+        default:
+        break;
+    }
+}
+
+static inline void std_h2d_req(){
+    switch(setup_packet.bRequest){
+        case SET_ADDRESS:
+            // new address will be assigned later - after  acknowlegement or request to host
+            USB_Dev.USB_Addr = setup_packet.wValue;
+        break;
+        case SET_CONFIGURATION:
+            // Now device configured
+            USB_Dev.USB_Status = USB_STATE_CONFIGURED;
+            configuration = setup_packet.wValue;
+        break;
+        default:
+        break;
+    }
+}
+
+/*
+bmRequestType: 76543210
+7    direction: 0 - host->device, 1 - device->host
+65   type: 0 - standard, 1 - class, 2 - vendor
+4..0 getter: 0 - device, 1 - interface, 2 - endpoint, 3 - other
+*/
+/**
+ * Endpoint0 (control) handler
+ */
+static void EP0_Handler(){
+    uint16_t epstatus = USB->EPnR[0]; // EP0R on input -> return this value after modifications
+    uint8_t reqtype = setup_packet.bmRequestType & 0x7f;
+    uint8_t dev2host = (setup_packet.bmRequestType & 0x80) ? 1 : 0;
+    int rxflag = RX_FLAG(epstatus);
+    if(rxflag && SETUP_FLAG(epstatus)){
+        switch(reqtype){
+            case STANDARD_DEVICE_REQUEST_TYPE: // standard device request
+                if(dev2host){
+                    std_d2h_req();
+                }else{
+                    std_h2d_req();
+                    EP_WriteIRQ(0, (uint8_t *)0, 0);
+                }
+            break;
+            case STANDARD_ENDPOINT_REQUEST_TYPE: // standard endpoint request
+                if(setup_packet.bRequest == CLEAR_FEATURE){
+                    EP_WriteIRQ(0, (uint8_t *)0, 0);
+                }
+            break;
+            case VENDOR_REQUEST_TYPE:
+                vendor_handler(&setup_packet);
+            break;
+            case CONTROL_REQUEST_TYPE:
+                switch(setup_packet.bRequest){
+                    case GET_LINE_CODING:
+                        EP_WriteIRQ(0, (uint8_t*)&lineCoding, sizeof(lineCoding));
+                    break;
+                    case SET_LINE_CODING: // omit this for next stage, when data will come
+                    break;
+                    case SET_CONTROL_LINE_STATE:
+                        usbON = 1;
+                        clstate_handler(setup_packet.wValue);
+                    break;
+                    case SEND_BREAK:
+                        usbON = 0;
+                        break_handler();
+                    break;
+                    default:
+                    break;
+                }
+                if(setup_packet.bRequest != GET_LINE_CODING) EP_WriteIRQ(0, (uint8_t *)0, 0); // write acknowledgement
+            break;
+            default:
+                EP_WriteIRQ(0, (uint8_t *)0, 0);
+        }
+    }else if(rxflag){ // got data over EP0 or host acknowlegement
+        if(endpoints[0].rx_cnt){
+            if(setup_packet.bRequest == SET_LINE_CODING){
+                linecoding_handler((usb_LineCoding*)ep0databuf);
+            }
+        }
+    } else if(TX_FLAG(epstatus)){ // package transmitted
+        // now we can change address after enumeration
+        if ((USB->DADDR & USB_DADDR_ADD) != USB_Dev.USB_Addr){
+            USB->DADDR = USB_DADDR_EF | USB_Dev.USB_Addr;
+            // change state to ADRESSED
+            USB_Dev.USB_Status = USB_STATE_ADDRESSED;
+        }
+    }
+    epstatus = KEEP_DTOG(USB->EPnR[0]);
+    if(rxflag) epstatus ^= USB_EPnR_STAT_TX; // start ZLP/data transmission
+    else epstatus &= ~USB_EPnR_STAT_TX; // or leave unchanged
+    // keep DTOGs, clear CTR_RX,TX, set RX VALID
+    USB->EPnR[0] = (epstatus & ~(USB_EPnR_CTR_RX|USB_EPnR_CTR_TX)) ^ USB_EPnR_STAT_RX;
+}
+
+static uint16_t lastaddr = LASTADDR_DEFAULT;
+/**
+ * Endpoint initialisation
+ * @param number - EP num (0...7)
+ * @param type - EP type (EP_TYPE_BULK, EP_TYPE_CONTROL, EP_TYPE_ISO, EP_TYPE_INTERRUPT)
+ * @param txsz - transmission buffer size @ USB/CAN buffer
+ * @param rxsz - reception buffer size @ USB/CAN buffer
+ * @param uint16_t (*func)(ep_t *ep) - EP handler function
+ * @return 0 if all OK
+ */
+int EP_Init(uint8_t number, uint8_t type, uint16_t txsz, uint16_t rxsz, void (*func)(ep_t ep)){
+    if(number >= STM32ENDPOINTS) return 4; // out of configured amount
+    if(txsz > USB_BTABLE_SIZE || rxsz > USB_BTABLE_SIZE) return 1; // buffer too large
+    if(lastaddr + txsz + rxsz >= USB_BTABLE_SIZE) return 2; // out of btable
+    USB->EPnR[number] = (type << 9) | (number & USB_EPnR_EA);
+    USB->EPnR[number] ^= USB_EPnR_STAT_RX | USB_EPnR_STAT_TX_1;
+    if(rxsz & 1 || rxsz > 512) return 3; // wrong rx buffer size
+    uint16_t countrx = 0;
+    if(rxsz < 64) countrx = rxsz / 2;
+    else{
+        if(rxsz & 0x1f) return 3; // should be multiple of 32
+        countrx = 31 + rxsz / 32;
+    }
+    USB_BTABLE->EP[number].USB_ADDR_TX = lastaddr;
+    endpoints[number].tx_buf = (uint16_t *)(USB_BTABLE_BASE + lastaddr*2);
+    endpoints[number].txbufsz = txsz;
+    lastaddr += txsz;
+    USB_BTABLE->EP[number].USB_COUNT_TX = 0;
+    USB_BTABLE->EP[number].USB_ADDR_RX = lastaddr;
+    endpoints[number].rx_buf = (uint16_t *)(USB_BTABLE_BASE + lastaddr*2);
+    lastaddr += rxsz;
+    USB_BTABLE->EP[number].USB_COUNT_RX = countrx << 10;
+    endpoints[number].func = func;
+    return 0;
+}
+
+//extern int8_t dump;
+// standard IRQ handler
+void usb_lp_can_rx0_isr(){
+    if(USB->ISTR & USB_ISTR_RESET){
+        usbON = 0;
+        // Reinit registers
+        USB->CNTR = USB_CNTR_RESETM | USB_CNTR_CTRM | USB_CNTR_SUSPM | USB_CNTR_WKUPM;
+        USB->ISTR = 0;
+        // Endpoint 0 - CONTROL
+        // ON USB LS size of EP0 may be 8 bytes, but on FS it should be 64 bytes!
+        lastaddr = LASTADDR_DEFAULT;
+        // clear address, leave only enable bit
+        USB->DADDR = USB_DADDR_EF;
+        USB_Dev.USB_Status = USB_STATE_DEFAULT;
+        USB->ISTR = ~USB_ISTR_RESET;
+        if(EP_Init(0, EP_TYPE_CONTROL, USB_EP0_BUFSZ, USB_EP0_BUFSZ, EP0_Handler)){
+            return;
+        }
+    }
+    if(USB->ISTR & USB_ISTR_CTR){
+        // EP number
+        uint8_t n = USB->ISTR & USB_ISTR_EPID;
+        // copy status register
+        uint16_t epstatus = USB->EPnR[n];
+        // copy received bytes amount
+        endpoints[n].rx_cnt = USB_BTABLE->EP[n].USB_COUNT_RX & 0x3FF; // low 10 bits is counter
+        // check direction
+        if(USB->ISTR & USB_ISTR_DIR){ // OUT interrupt - receive data, CTR_RX==1 (if CTR_TX == 1 - two pending transactions: receive following by transmit)
+            if(n == 0){ // control endpoint
+                if(epstatus & USB_EPnR_SETUP){ // setup packet -> copy data to conf_pack
+                    EP_Read(0, (uint16_t*)&setup_packet);
+                    ep0dbuflen = 0;
+                    // interrupt handler will be called later
+                }else if(epstatus & USB_EPnR_CTR_RX){ // data packet -> push received data to ep0databuf
+                    ep0dbuflen = endpoints[0].rx_cnt;
+                    EP_Read(0, (uint16_t*)&ep0databuf);
+                }
+            }
+        }
+        // call EP handler
+        if(endpoints[n].func) endpoints[n].func(endpoints[n]);
+    }
+    if(USB->ISTR & USB_ISTR_SUSP){ // suspend -> still no connection, may sleep
+        usbON = 0;
+        USB->CNTR |= USB_CNTR_FSUSP | USB_CNTR_LP_MODE;
+        USB->ISTR = ~USB_ISTR_SUSP;
+    }
+    if(USB->ISTR & USB_ISTR_WKUP){ // wakeup
+        USB->CNTR &= ~(USB_CNTR_FSUSP | USB_CNTR_LP_MODE); // clear suspend flags
+        USB->ISTR = ~USB_ISTR_WKUP;
+    }
+}
+
+/**
+ * Write data to EP buffer (called from IRQ handler)
+ * @param number - EP number
+ * @param *buf - array with data
+ * @param size - its size
+ */
+void EP_WriteIRQ(uint8_t number, const uint8_t *buf, uint16_t size){
+    uint8_t i;
+    if(size > endpoints[number].txbufsz) size = endpoints[number].txbufsz;
+    uint16_t N2 = (size + 1) >> 1;
+    // the buffer is 16-bit, so we should copy data as it would be uint16_t
+    uint16_t *buf16 = (uint16_t *)buf;
+    uint32_t *out = (uint32_t *)endpoints[number].tx_buf;
+    for(i = 0; i < N2; ++i, ++out){
+        *out = buf16[i];
+    }
+    USB_BTABLE->EP[number].USB_COUNT_TX = size;
+}
+
+/**
+ * Write data to EP buffer (called outside IRQ handler)
+ * @param number - EP number
+ * @param *buf - array with data
+ * @param size - its size
+ */
+void EP_Write(uint8_t number, const uint8_t *buf, uint16_t size){
+    EP_WriteIRQ(number, buf, size);
+    uint16_t status = KEEP_DTOG(USB->EPnR[number]);
+    // keep DTOGs, clear CTR_TX & set TX VALID to start transmission
+    USB->EPnR[number] = (status & ~(USB_EPnR_CTR_TX)) ^ USB_EPnR_STAT_TX;
+}
+
+/*
+ * Copy data from EP buffer into user buffer area
+ * @param *buf - user array for data
+ * @return amount of data read
+ */
+int EP_Read(uint8_t number, uint16_t *buf){
+    int sz = endpoints[number].rx_cnt;
+    if(!sz) return 0;
+    endpoints[number].rx_cnt = 0;
+    int n = (sz + 1) >> 1;
+    uint32_t *in = (uint32_t *)endpoints[number].rx_buf;
+    if(n){
+        for(int i = 0; i < n; ++i, ++in)
+            buf[i] = *(uint16_t*)in;
+    }
+    return sz;
+}
+

F1:F103/F1_testbrd/usb_lib.h

@@ -0,0 +1,189 @@
+/*
+ *                                                                                                  geany_encoding=koi8-r
+ * usb_lib.h
+ *
+ * Copyright 2018 Edward V. Emelianov <eddy@sao.ru, edward.emelianoff@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301, USA.
+ *
+ */
+
+#pragma once
+#ifndef __USB_LIB_H__
+#define __USB_LIB_H__
+
+#include <wchar.h>
+#include "usb_defs.h"
+
+#define EP0DATABUF_SIZE                 (64)
+#define LASTADDR_DEFAULT                (STM32ENDPOINTS * 8)
+
+// bmRequestType & 0x7f
+#define STANDARD_DEVICE_REQUEST_TYPE    0
+#define STANDARD_ENDPOINT_REQUEST_TYPE  2
+#define VENDOR_REQUEST_TYPE             0x40
+#define CONTROL_REQUEST_TYPE            0x21
+// bRequest, standard; for bmRequestType == 0x80
+#define GET_STATUS                      0x00
+#define GET_DESCRIPTOR                  0x06
+#define GET_CONFIGURATION               0x08
+// for bmRequestType == 0
+#define CLEAR_FEATURE                   0x01
+#define SET_FEATURE                     0x03    // unused
+#define SET_ADDRESS                     0x05
+#define SET_DESCRIPTOR                  0x07    // unused
+#define SET_CONFIGURATION               0x09
+// for bmRequestType == 0x81, 1 or 0xB2
+#define GET_INTERFACE                   0x0A    // unused
+#define SET_INTERFACE                   0x0B    // unused
+#define SYNC_FRAME                      0x0C    // unused
+#define VENDOR_REQUEST                  0x01    // unused
+
+// Class-Specific Control Requests
+#define SEND_ENCAPSULATED_COMMAND       0x00    // unused
+#define GET_ENCAPSULATED_RESPONSE       0x01    // unused
+#define SET_COMM_FEATURE                0x02    // unused
+#define GET_COMM_FEATURE                0x03    // unused
+#define CLEAR_COMM_FEATURE              0x04    // unused
+#define SET_LINE_CODING                 0x20
+#define GET_LINE_CODING                 0x21
+#define SET_CONTROL_LINE_STATE          0x22
+#define SEND_BREAK                      0x23
+
+// control line states
+#define CONTROL_DTR                     0x01
+#define CONTROL_RTS                     0x02
+
+// wValue
+#define DEVICE_DESCRIPTOR               0x100
+#define CONFIGURATION_DESCRIPTOR        0x200
+#define STRING_LANG_DESCRIPTOR          0x300
+#define STRING_MAN_DESCRIPTOR           0x301
+#define STRING_PROD_DESCRIPTOR          0x302
+#define STRING_SN_DESCRIPTOR            0x303
+#define DEVICE_QUALIFIER_DESCRIPTOR     0x600
+
+#define RX_FLAG(epstat)                 (epstat & USB_EPnR_CTR_RX)
+#define TX_FLAG(epstat)                 (epstat & USB_EPnR_CTR_TX)
+#define SETUP_FLAG(epstat)              (epstat & USB_EPnR_SETUP)
+
+// EPnR bits manipulation
+#define KEEP_DTOG_STAT(EPnR)            (EPnR & ~(USB_EPnR_STAT_RX|USB_EPnR_STAT_TX|USB_EPnR_DTOG_RX|USB_EPnR_DTOG_TX))
+#define KEEP_DTOG(EPnR)                 (EPnR & ~(USB_EPnR_DTOG_RX|USB_EPnR_DTOG_TX))
+
+// USB state: uninitialized, addressed, ready for use
+typedef enum{
+    USB_STATE_DEFAULT,
+    USB_STATE_ADDRESSED,
+    USB_STATE_CONFIGURED,
+    USB_STATE_CONNECTED
+} USB_state;
+
+// EP types
+#define EP_TYPE_BULK                    0x00
+#define EP_TYPE_CONTROL                 0x01
+#define EP_TYPE_ISO                     0x02
+#define EP_TYPE_INTERRUPT               0x03
+
+#define LANG_US (uint16_t)0x0409
+
+#define _USB_STRING_(name, str)                  \
+static const struct name \
+{                          \
+        uint8_t  bLength;                       \
+        uint8_t  bDescriptorType;               \
+        uint16_t bString[(sizeof(str) - 2) / 2]; \
+    \
+} \
+name = {sizeof(name), 0x03, str}
+
+#define _USB_LANG_ID_(name, lng_id)     \
+    \
+static const struct name \
+{         \
+        uint8_t  bLength;         \
+        uint8_t  bDescriptorType; \
+        uint16_t bString;         \
+    \
+} \
+name = {0x04, 0x03, lng_id}
+#define STRING_LANG_DESCRIPTOR_SIZE_BYTE    (4)
+
+// EP0 configuration packet
+typedef struct {
+    uint8_t bmRequestType;
+    uint8_t bRequest;
+    uint16_t wValue;
+    uint16_t wIndex;
+    uint16_t wLength;
+} config_pack_t;
+
+// endpoints state
+typedef struct{
+    uint16_t *tx_buf;           // transmission buffer address
+    uint16_t txbufsz;           // transmission buffer size
+    uint16_t *rx_buf;           // reception buffer address
+    void (*func)();             // endpoint action function
+    unsigned rx_cnt  : 10;      // received data counter
+} ep_t;
+
+// USB status & its address
+typedef struct {
+    uint8_t  USB_Status;
+    uint16_t USB_Addr;
+}usb_dev_t;
+
+typedef struct {
+    uint32_t dwDTERate;
+    uint8_t bCharFormat;
+    #define USB_CDC_1_STOP_BITS   0
+    #define USB_CDC_1_5_STOP_BITS 1
+    #define USB_CDC_2_STOP_BITS   2
+    uint8_t bParityType;
+    #define USB_CDC_NO_PARITY     0
+    #define USB_CDC_ODD_PARITY    1
+    #define USB_CDC_EVEN_PARITY   2
+    #define USB_CDC_MARK_PARITY   3
+    #define USB_CDC_SPACE_PARITY  4
+    uint8_t bDataBits;
+} __attribute__ ((packed)) usb_LineCoding;
+
+typedef struct {
+    uint8_t   bmRequestType;
+    uint8_t   bNotificationType;
+    uint16_t  wValue;
+    uint16_t  wIndex;
+    uint16_t  wLength;
+} __attribute__ ((packed)) usb_cdc_notification;
+
+extern ep_t endpoints[];
+extern usb_dev_t USB_Dev;
+extern uint8_t usbON;
+
+void USB_Init();
+void USB_ResetState();
+int EP_Init(uint8_t number, uint8_t type, uint16_t txsz, uint16_t rxsz, void (*func)());
+void EP_WriteIRQ(uint8_t number, const uint8_t *buf, uint16_t size);
+void EP_Write(uint8_t number, const uint8_t *buf, uint16_t size);
+int EP_Read(uint8_t number, uint16_t *buf);
+usb_LineCoding getLineCoding();
+
+void linecoding_handler(usb_LineCoding *lc);
+void clstate_handler(uint16_t val);
+void break_handler();
+void vendor_handler(config_pack_t *packet);
+
+#endif // __USB_LIB_H__

F1:F103/I2Cscan/Makefile

@@ -0,0 +1,139 @@
+BINARY		= I2Cscan
+BOOTPORT	?= /dev/ttyUSB0
+BOOTSPEED	?= 115200
+# MCU FAMILY
+FAMILY		?= F1
+# MCU code
+MCU			?= F103x8
+# density (stm32f10x.h, lines 70-84)
+DENSITY 	?= MD
+# change this linking script depending on particular MCU model,
+LDSCRIPT	?= stm32f103x8.ld
+# debug
+#DEFS		= -DEBUG
+
+INDEPENDENT_HEADERS=
+
+FP_FLAGS	?= -msoft-float -mfloat-abi=soft
+ASM_FLAGS	?= -mthumb -mcpu=cortex-m3 -mfix-cortex-m3-ldrd
+ARCH_FLAGS	= $(ASM_FLAGS) $(FP_FLAGS)
+
+###############################################################################
+# Executables
+#PREFIX		?= arm-none-eabi
+# gcc from arm web site 
+PREFIX		?= /opt/bin/arm-none-eabi
+TOOLCHLIB	?= /opt/arm-none-eabi/lib
+RM			:= rm -f
+RMDIR		:= rmdir
+CC			:= $(PREFIX)-gcc
+# don't replace ld with gcc: the binary size would be much greater!!
+LD			:= $(PREFIX)-ld
+AR			:= $(PREFIX)-ar
+AS			:= $(PREFIX)-as
+SIZE 		:= $(PREFIX)-size
+OBJCOPY		:= $(PREFIX)-objcopy
+OBJDUMP		:= $(PREFIX)-objdump
+GDB			:= $(PREFIX)-gdb
+STFLASH		:= $(shell which st-flash)
+STBOOT		:= $(shell which stm32flash)
+DFUUTIL		:= $(shell which dfu-util)
+
+###############################################################################
+# Source files
+OBJDIR 		= mk
+SRC			:= $(wildcard *.c)
+OBJS		:= $(addprefix $(OBJDIR)/, $(SRC:%.c=%.o))
+STARTUP		= $(OBJDIR)/startup.o
+OBJS 		+= $(STARTUP)
+# dependencies: we need them to recompile files if their headers-dependencies changed
+DEPS		:= $(OBJS:.o=.d)
+
+INC_DIR ?= ../inc
+
+INCLUDE 	:= -I$(INC_DIR)/Fx -I$(INC_DIR)/cm
+LIB_DIR		:= $(INC_DIR)/ld
+
+###############################################################################
+# C flags
+CFLAGS		+= -O2 -g -D__thumb2__=1 -MD
+CFLAGS		+= -Wall -Werror -Wextra -Wshadow 
+CFLAGS		+= -fno-common -ffunction-sections -fdata-sections -fno-stack-protector
+CFLAGS		+=  $(ARCH_FLAGS)
+
+###############################################################################
+# Linker flags
+LDFLAGS		+= -nostartfiles --static -nostdlibs 
+LDFLAGS		+= -L$(LIB_DIR) -L$(TOOLCHLIB)
+LDFLAGS		+= -T$(LDSCRIPT)
+
+###############################################################################
+# Used libraries
+LDLIBS		+=  -lc $(shell $(CC) $(CFLAGS) -print-libgcc-file-name)
+
+DEFS		+= -DSTM32$(FAMILY) -DSTM32$(MCU) -DSTM32F10X_$(DENSITY)
+
+ELF		:= $(OBJDIR)/$(BINARY).elf
+LIST	:= $(OBJDIR)/$(BINARY).list
+BIN		:= $(BINARY).bin
+HEX		:= $(BINARY).hex
+
+all: bin list size
+
+elf: $(ELF)
+bin: $(BIN)
+hex: $(HEX)
+list: $(LIST)
+
+ifneq ($(MAKECMDGOALS),clean)
+-include $(DEPS)
+endif
+
+$(OBJDIR):
+	mkdir $(OBJDIR)
+
+$(STARTUP): $(INC_DIR)/startup/vector.c
+	$(CC) $(CFLAGS) $(DEFS) $(INCLUDE) -o $@ -c $<
+
+$(OBJDIR)/%.o: %.c
+	@echo "  CC      $<"
+	$(CC) $(CFLAGS) $(DEFS) $(INCLUDE) -o $@ -c $<
+
+$(BIN): $(ELF)
+	@echo "  OBJCOPY $(BIN)"
+	$(OBJCOPY) -Obinary $(ELF) $(BIN)
+
+$(HEX): $(ELF)
+	@echo "  OBJCOPY $(HEX)"
+	$(OBJCOPY) -Oihex $(ELF) $(HEX)
+
+$(LIST): $(ELF)
+	@echo "  OBJDUMP $(LIST)"
+	$(OBJDUMP) -S $(ELF) > $(LIST)
+
+$(ELF): $(OBJDIR) $(OBJS)
+	@echo "  LD      $(ELF)"
+	$(LD) $(LDFLAGS) $(OBJS) $(LDLIBS) -o $(ELF)
+
+size: $(ELF)
+	$(SIZE) $(ELF)    
+
+clean:
+	@echo "  CLEAN"
+	$(RM) $(OBJS) $(DEPS) $(ELF) $(HEX) $(LIST)
+	@rmdir $(OBJDIR) 2>/dev/null || true
+
+
+flash: $(BIN)
+	@echo "  FLASH  $(BIN)"
+	$(STFLASH) write $(BIN) 0x8000000
+
+boot: $(BIN)
+	@echo "  LOAD $(BIN) through bootloader"
+	$(STBOOT) -b$(BOOTSPEED) $(BOOTPORT) -w $(BIN)
+
+dfuboot: $(BIN)
+	@echo "  LOAD  $(BIN) THROUGH DFU"
+	$(DFUUTIL) -a0 -D $(BIN) -s 0x08000000
+
+.PHONY: clean flash boot

F1:F103/I2Cscan/Readme

@@ -0,0 +1 @@
+Scan I2C bus, read/write registers

F1:F103/I2Cscan/hardware.c

@@ -0,0 +1,48 @@
+/*
+ * This file is part of the I2Cscan project.
+ * Copyright 2020 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "hardware.h"
+
+static inline void gpio_setup(){
+    // Enable clocks to the GPIO subsystems (PB for ADC), turn on AFIO clocking to disable SWD/JTAG
+    RCC->APB2ENR |= RCC_APB2ENR_IOPAEN | RCC_APB2ENR_IOPCEN | RCC_APB2ENR_AFIOEN;
+    // turn off SWJ/JTAG
+//    AFIO->MAPR = AFIO_MAPR_SWJ_CFG_DISABLE;
+    AFIO->MAPR = AFIO_MAPR_SWJ_CFG_JTAGDISABLE; // for PA15
+    // Set led as opendrain output
+    GPIOC->CRH |= CRH(13, CNF_ODOUTPUT|MODE_SLOW);
+    // USB pullup (PA15) - pushpull output
+    GPIOA->CRH = CRH(15, CNF_PPOUTPUT|MODE_SLOW);
+}
+
+void hw_setup(){
+    gpio_setup();
+}
+
+void iwdg_setup(){
+    uint32_t tmout = 16000000;
+    RCC->CSR |= RCC_CSR_LSION;
+    while((RCC->CSR & RCC_CSR_LSIRDY) != RCC_CSR_LSIRDY){if(--tmout == 0) break;} /* (2) */
+    IWDG->KR = IWDG_START;
+    IWDG->KR = IWDG_WRITE_ACCESS;
+    IWDG->PR = IWDG_PR_PR_1;
+    IWDG->RLR = 1250;
+    tmout = 16000000;
+    while(IWDG->SR){if(--tmout == 0) break;}
+    IWDG->KR = IWDG_REFRESH;
+}

F1:F103/I2Cscan/hardware.h

@@ -0,0 +1,43 @@
+/*
+ * This file is part of the I2Cscan project.
+ * Copyright 2020 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#ifndef __HARDWARE_H__
+#define __HARDWARE_H__
+
+#include "stm32f1.h"
+
+// LED0 - PC13 (bluepill), blinking each second
+#define LED0_port   GPIOC
+#define LED0_pin    (1<<13)
+
+// USB pullup (not present in bluepill, should be soldered) - PA15
+#define USBPU_port  GPIOA
+#define USBPU_pin   (1<<15)
+#define USBPU_ON()  pin_set(USBPU_port, USBPU_pin)
+#define USBPU_OFF() pin_clear(USBPU_port, USBPU_pin)
+
+#define LED_blink(x)    pin_toggle(x ## _port, x ## _pin)
+#define LED_on(x)       pin_clear(x ## _port, x ## _pin)
+#define LED_off(x)      pin_set(x ## _port, x ## _pin)
+
+void hw_setup();
+void iwdg_setup();
+
+
+#endif // __HARDWARE_H__