add usart_blink

F0/Readme.md

@@ -3,3 +3,4 @@ Samples for STM32F042-nucleo and chinese STM32F030-based devboard
 
 - blink - simple LED blink
 - uart - USART over DMA with hardware end-of-string detection
+- uart_blink - code for STM32F030F4, echo data on USART1 and blink LEDS on PA4 and PA5

F0/uart_blink/Makefile

@@ -0,0 +1,137 @@
+BINARY		= uartblink
+BOOTPORT	?= /dev/ttyUSB0
+BOOTSPEED	?= 115200
+# MCU FAMILY
+FAMILY		= F0
+# MCU code
+MCU			= F030x4
+DEFS		= -DEBUG
+# change this linking script depending on particular MCU model,
+# for example, if you have STM32F103VBT6, you should write:
+LDSCRIPT	= ld/stm32f030f.ld
+
+INDEPENDENT_HEADERS=
+
+FP_FLAGS	?= -msoft-float
+ASM_FLAGS	= -mthumb -mcpu=cortex-m0 -march=armv6-m -mtune=cortex-m0
+ARCH_FLAGS	= $(ASM_FLAGS) $(FP_FLAGS)
+
+###############################################################################
+# Executables
+PREFIX		?= /opt/bin/arm-none-eabi
+
+RM			:= rm -f
+RMDIR		:= rmdir
+CC			:= $(PREFIX)-gcc
+LD			:= $(PREFIX)-gcc
+AR			:= $(PREFIX)-ar
+AS			:= $(PREFIX)-as
+OBJCOPY		:= $(PREFIX)-objcopy
+OBJDUMP		:= $(PREFIX)-objdump
+GDB			:= $(PREFIX)-gdb
+STFLASH		:= $(shell which st-flash)
+STBOOT		:= $(shell which stm32flash)
+
+###############################################################################
+# Source files
+OBJDIR 		= mk
+LDSCRIPT	?= $(BINARY).ld
+SRC			:= $(wildcard *.c)
+OBJS		:= $(addprefix $(OBJDIR)/, $(SRC:%.c=%.o))
+STARTUP		= $(OBJDIR)/startup.o
+OBJS 		+= $(STARTUP)
+DEPS		:= $(OBJS:.o=.d)
+
+INC_DIR ?= ../inc
+
+INCLUDE 	:= -I$(INC_DIR)/F0 -I$(INC_DIR)/cm
+LIB_DIR		:= $(INC_DIR)/ld
+
+###############################################################################
+# C flags
+CFLAGS		+= -O2 -g -MD -D__thumb2__=1
+CFLAGS		+= -Wall -Werror -Wextra -Wshadow -Wimplicit-function-declaration
+CFLAGS		+= -Wredundant-decls $(INCLUDE)
+# -Wmissing-prototypes -Wstrict-prototypes
+CFLAGS		+= -fno-common -ffunction-sections -fdata-sections
+
+###############################################################################
+# Linker flags
+LDFLAGS		+= --static -nostartfiles
+#--specs=nano.specs
+LDFLAGS		+= -L$(LIB_DIR)
+LDFLAGS		+= -T$(LDSCRIPT)
+LDFLAGS		+= -Wl,-Map=$(OBJDIR)/$(BINARY).map
+LDFLAGS		+= -Wl,--gc-sections
+
+###############################################################################
+# Used libraries
+LDLIBS		+= -Wl,--start-group -lc -lgcc -Wl,--end-group
+LDLIBS		+= $(shell $(CC) $(CFLAGS) -print-libgcc-file-name)
+
+DEFS		+= -DSTM32$(FAMILY) -DSTM32$(MCU)
+
+#.SUFFIXES: .elf .bin .hex .srec .list .map .images
+#.SECONDEXPANSION:
+#.SECONDARY:
+
+ELF		:= $(OBJDIR)/$(BINARY).elf
+LIST	:= $(OBJDIR)/$(BINARY).list
+BIN		:= $(BINARY).bin
+HEX		:= $(BINARY).hex
+
+all: bin list
+
+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) $(ARCH_FLAGS) -o $@ -c $<
+
+$(OBJDIR)/%.o: %.c
+	@echo "  CC      $<"
+	$(CC) $(CFLAGS) $(DEFS) $(INCLUDE) $(ARCH_FLAGS) -o $@ -c $<
+
+#$(OBJDIR)/%.d: %.c $(OBJDIR)
+#	$(CC) -MM -MG $< | sed -e 's,^\([^:]*\)\.o[ ]*:,$(@D)/\1.o $(@D)/\1.d:,' >$@
+
+$(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) $(ARCH_FLAGS) $(OBJS) $(LDLIBS) -o $(ELF)
+
+clean:
+	@echo "  CLEAN"
+	$(RM) $(OBJS) $(DEPS) $(ELF) $(HEX) $(LIST) $(OBJDIR)/*.map
+	@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)
+
+.PHONY: clean flash boot

F0/uart_blink/Readme.md

@@ -0,0 +1,6 @@
+Code for STM32F030F4 chinese board
+- Toggle onboard green LED once per second.
+- Echo received by USART1 data (not more than 64 bytes including '\n') on B115200:
+	- if PA6 not connected to ground echo text directly
+	- otherwice echo it reversly
+- Light up LED on PA5 (opendrain) when receive data and turn it off when send.

F0/uart_blink/ld/stm32f030f.ld

@@ -0,0 +1,12 @@
+/* Linker script for STM32F030f4, 16K flash, 4K RAM. */
+
+/* Define memory regions. */
+MEMORY
+{
+    rom   (rx) : ORIGIN = 0x08000000, LENGTH = 16K
+    ram  (rwx) : ORIGIN = 0x20000000, LENGTH = 4K
+}
+
+/* Include the common ld script. */
+INCLUDE stm32f0.ld
+

F0/uart_blink/main.c

@@ -0,0 +1,84 @@
+/*
+ * 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 "stm32f0.h"
+#include "usart.h"
+
+volatile uint32_t Tms = 0;
+
+/* Called when systick fires */
+void sys_tick_handler(void){
+    ++Tms;
+}
+
+static void gpio_setup(void){
+    /* Enable clocks to the GPIO subsystems (A&B) */
+    RCC->AHBENR |= RCC_AHBENR_GPIOAEN;
+    /* Set green leds (PA5 & PA4) as output */
+    GPIOA->MODER = GPIO_MODER_MODER4_O | GPIO_MODER_MODER5_O;
+    GPIOA->OTYPER = 1 << 5; // PA5 - opendrain, PA4 - pushpull
+    /* PA6 - switch blink rate (pullup input) */
+    GPIOA->PUPDR = GPIO_PUPDR_PUPDR6_0;
+}
+
+/**
+ * reverce line
+ */
+char *rline(char *in, int L){
+    static char out[UARTBUFSZ];
+    if(L > UARTBUFSZ - 1) return in;
+    char *optr = out, *iptr = &in[L-1];
+    for(; L > 0; --L) *optr++ = *iptr--;
+    *optr = '\n';
+    return out;
+}
+
+int main(void){
+    uint32_t lastT = 0;
+    int L = 0;
+    char *txt;
+    sysreset();
+    SysTick_Config(6000, 1);
+    gpio_setup();
+    USART1_config();
+    //StartHSE();
+    pin_set(GPIOA, 1<<5); // clear extern LED
+    /* Do nothing in main loop */
+    while (1){
+        if(lastT > Tms || Tms - lastT > 499){
+            pin_toggle(GPIOA, 1<<4); // blink by onboard LED once per second
+            lastT = Tms;
+        }
+        if(usart1rx()){ // usart1 received data, store in in buffer
+            L = usart1_getline(&txt);
+            if(!pin_read(GPIOA, 1<<6)){ // there's a jumper: reverse string
+                txt = rline(txt, L);
+            }
+            pin_clear(GPIOA, 1<<5); // set extern LED
+        }
+        if(L){ // text waits for sending
+            if(ALL_OK == usart1_send(txt, L)){
+                L = 0;
+                pin_set(GPIOA, 1<<5); // clear extern LED
+            }
+        }
+    }
+}

F0/uart_blink/usart.c

@@ -0,0 +1,153 @@
+/*
+ * usart.c
+ *
+ * Copyright 2017 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 <string.h> // memcpy
+
+extern volatile uint32_t Tms;
+
+static int datalen[2] = {0,0}; // received data line length (including '\n')
+
+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
+    txdlen = 0          // length of transmitted data
+;
+
+static int  rbufno = 0, // current rbuf number
+            txnum = 0;  // current number of transmitted symbol in tbuf
+static char rbuf[2][UARTBUFSZ], tbuf[UARTBUFSZ]; // receive & transmit buffers
+static char *recvdata = NULL;
+
+void USART1_config(){
+    /* Enable the peripheral clock of GPIOA */
+    RCC->AHBENR |= RCC_AHBENR_GPIOAEN;
+    /* GPIO configuration for USART1 signals */
+    /* (1) Select AF mode (10) on PA9 and PA10 */
+    /* (2) AF1 for USART1 signals */
+    GPIOA->MODER = (GPIOA->MODER & ~(GPIO_MODER_MODER9|GPIO_MODER_MODER10))\
+                | (GPIO_MODER_MODER9_1 | GPIO_MODER_MODER10_1); /* (1) */
+    GPIOA->AFR[1] = (GPIOA->AFR[1] &~ (GPIO_AFRH_AFRH1 | GPIO_AFRH_AFRH2))\
+                | (1 << (1 * 4)) | (1 << (2 * 4)); /* (2) */
+    /* Enable the peripheral clock USART1 */
+    RCC->APB2ENR |= RCC_APB2ENR_USART1EN;
+    /* Configure USART1 */
+    /* (1) oversampling by 16, 115200 baud */
+    /* (2) 8 data bit, 1 start bit, 1 stop bit, no parity */
+    USART1->BRR = 480000 / 1152; /* (1) */
+    USART1->CR1 = USART_CR1_TE | USART_CR1_RE | USART_CR1_UE; /* (2) */
+    /* polling idle frame Transmission */
+    while(!(USART1->ISR & USART_ISR_TC)){}
+    USART1->ICR |= USART_ICR_TCCF;/* clear TC flag */
+    USART1->CR1 |= USART_CR1_TCIE | USART_CR1_TXEIE | USART_CR1_RXNEIE;/* enable TC, TXE & RXNE interrupt */
+    /* Configure IT */
+    /* (3) Set priority for USART1_IRQn */
+    /* (4) Enable USART1_IRQn */
+    NVIC_SetPriority(USART1_IRQn, 0); /* (3) */
+    NVIC_EnableIRQ(USART1_IRQn); /* (4) */
+}
+
+void usart1_isr(){
+    #ifdef CHECK_TMOUT
+    static uint32_t tmout = 0;
+    #endif
+    if(USART1->ISR & USART_ISR_TC){ // Transmission complete
+        USART1->ICR |= USART_ICR_TCCF; /* Clear transfer complete flag */
+        txrdy = 1;
+    }
+    if(USART1->ISR & USART_ISR_TXE){ // TX emty - send next char
+        // clear by writing to TDR
+        if(txnum < txdlen){
+            USART1->TDR = tbuf[txnum++];
+        }else
+        USART1->CR1 &= ~USART_CR1_TXEIE; // turn off interrupt
+    }
+    if(USART1->ISR & USART_ISR_RXNE){ // RX not emty - receive next char
+        #ifdef CHECK_TMOUT
+        if(tmout && Tms >= tmout){ // set overflow flag
+            bufovr = 1;
+            datalen[rbufno] = 0;
+        }
+        tmout = Tms + TIMEOUT_MS;
+        if(!tmout) tmout = 1; // prevent 0
+        #endif
+        // read RDR clears flag
+        uint8_t rb = USART1->RDR;
+        if(datalen[rbufno] < UARTBUFSZ){ // put next char into buf
+            rbuf[rbufno][datalen[rbufno]++] = rb;
+            if(rb == '\n'){ // got newline - line ready
+                linerdy = 1;
+                dlen = datalen[rbufno];
+                recvdata = rbuf[rbufno];
+                // prepare other buffer
+                rbufno = !rbufno;
+                datalen[rbufno] = 0;
+                #ifdef CHECK_TMOUT
+                // clear timeout at line end
+                tmout = 0;
+                #endif
+            }
+        }else{ // buffer overrun
+            bufovr = 1;
+            datalen[rbufno] = 0;
+            #ifdef CHECK_TMOUT
+            tmout = 0;
+            #endif
+        }
+    }
+}
+
+/**
+ * return length of received data (without trailing zero
+ */
+int usart1_getline(char **line){
+    if(bufovr){
+        bufovr = 0;
+        linerdy = 0;
+        return 0;
+    }
+    *line = recvdata;
+    linerdy = 0;
+    return dlen;
+}
+
+TXstatus usart1_send(const char *str, int len){
+    if(!txrdy) return LINE_BUSY;
+    if(len > UARTBUFSZ) return STR_TOO_LONG;
+    txrdy = 0;
+    txdlen = len;
+    memcpy(tbuf, str, len);
+    txnum = 0;
+    USART1->CR1 |= USART_CR1_TXEIE; // allow IRQ
+    return ALL_OK;
+}
+
+TXstatus usart1_send_blocking(const char *str, int len){
+    if(!txrdy) return LINE_BUSY;
+    int i;
+    for(i = 0; i < len; ++i){
+        USART1->TDR = *str++;
+        while(!(USART1->ISR & USART_ISR_TXE));
+    }
+    txrdy = 1;
+    return ALL_OK;
+}

F0/uart_blink/usart.h

@@ -0,0 +1,51 @@
+/*
+ * usart.h
+ *
+ * Copyright 2017 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 __USART_H__
+#define __USART_H__
+
+#include "stm32f0.h"
+
+// input and output buffers size
+#define UARTBUFSZ  (64)
+// timeout between data bytes
+#define TIMEOUT_MS (1500)
+// check timeout
+#define CHECK_TMOUT
+
+typedef enum{
+    ALL_OK,
+    LINE_BUSY,
+    STR_TOO_LONG
+} TXstatus;
+
+#define usart1rx()  (linerdy)
+#define usart1ovr() (bufovr)
+
+extern int linerdy, bufovr, txrdy;
+
+void USART1_config();
+int usart1_getline(char **line);
+TXstatus usart1_send(const char *str, int len);
+TXstatus usart1_send_blocking(const char *str, int len);
+
+
+#endif // __USART_H__