diff --git a/F1:F103/F1_testbrd/F1_testbrd.files b/F1:F103/F1_testbrd/F1_testbrd.files
index 26b3859..df40d50 100644
--- a/F1:F103/F1_testbrd/F1_testbrd.files
+++ b/F1:F103/F1_testbrd/F1_testbrd.files
@@ -9,6 +9,10 @@ main.c
 pl2303.bin
 proto.c
 proto.h
+ringbuffer.c
+ringbuffer.h
+strfunc.c
+strfunc.h
 usart.c
 usart.h
 usb.c
@@ -16,3 +20,5 @@ usb.h
 usb_defs.h
 usb_lib.c
 usb_lib.h
+usbhw.c
+usbhw.h
diff --git a/F1:F103/F1_testbrd/Makefile b/F1:F103/F1_testbrd/Makefile
index 1675bb4..f2b1689 100644
--- a/F1:F103/F1_testbrd/Makefile
+++ b/F1:F103/F1_testbrd/Makefile
@@ -1,139 +1,9 @@
-BINARY		= pl2303
-BOOTPORT	?= /dev/ttyUSB0
-BOOTSPEED	?= 115200
-# MCU FAMILY
-FAMILY		?= F1
+BINARY      := pl2303
 # MCU code
-MCU			?= F103x6
-# density (stm32f10x.h, lines 70-84)
-DENSITY 	?= LD
+MCU         ?= F103x6
 # change this linking script depending on particular MCU model,
-LDSCRIPT	?= stm32f103x6.ld
-# debug
-DEFS		= -DEBUG
+LDSCRIPT    ?= stm32f103x6.ld
+DEFINES     := -DSTM32F10X_LD -DUSB1_16 
 
-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
+include ../makefile.f1
+include ../../makefile.stm32
diff --git a/F1:F103/F1_testbrd/hardware.h b/F1:F103/F1_testbrd/hardware.h
index bffefeb..d79d47a 100644
--- a/F1:F103/F1_testbrd/hardware.h
+++ b/F1:F103/F1_testbrd/hardware.h
@@ -19,11 +19,5 @@
 #pragma once
 #include <stm32f1.h>
 
-// USB pullup (not used in STM32F0x2!) - PA13
-#define USBPU_port  GPIOA
-#define USBPU_pin   (1<<15)
-#define USBPU_ON()  pin_clear(USBPU_port, USBPU_pin)
-#define USBPU_OFF() pin_set(USBPU_port, USBPU_pin)
-
 void hw_setup();
 
diff --git a/F1:F103/F1_testbrd/main.c b/F1:F103/F1_testbrd/main.c
index 77b8521..a46fe7b 100644
--- a/F1:F103/F1_testbrd/main.c
+++ b/F1:F103/F1_testbrd/main.c
@@ -38,14 +38,16 @@ volatile uint8_t ADCmon = 0; // ==1 to monitor ADC (change PWM of LEDS & show cu
 uint16_t oldADCval = 0;
 
 int main(void){
+    char tmpbuf[129];
     uint32_t lastT = 0;
     sysreset();
     StartHSE();
+
+    USBPU_OFF();
     hw_setup();
     usart_setup();
     SysTick_Config(72000);
 
-    USBPU_OFF();
     USB_setup();
     USBPU_ON();
 
@@ -68,7 +70,8 @@ int main(void){
                 int32_t d = v - oldADCval;
                 if(d < -ADCthreshold || d > ADCthreshold){
                     oldADCval = v;
-                    printADCvals();
+                    printADCvals(USB_sendstr);
+                    printADCvals(usart_send);
                     v >>= 2; // 10 bits
                     TIM3->CCR1 = TIM3->CCR2 = TIM3->CCR3 = 0xff; TIM3->CCR4 = 0;
                     if(v >= 0x300) TIM3->CCR4 = v - 0x300;
@@ -90,31 +93,29 @@ int main(void){
                 USND(") - found device\n");
             }
         }
-        usb_proc();
         int r = 0;
         char *txt, *ans;
-        if((txt = get_USB())){
-            ans = (char*)parse_cmd(txt);
+        int l = USB_receivestr(tmpbuf, 128);
+        if(l){
             SEND("Received data over USB:\n");
-            SEND(txt);
-            newline();
+            SEND(tmpbuf);
+            usart_newline();
+            ans = (char*)parse_cmd(USB_sendstr, tmpbuf);
             if(ans){
-                uint16_t l = 0; char *p = ans;
-                while(*p++) l++;
-                USB_send((uint8_t*)ans, l);
-                if(ans[l-1] != '\n') USND("\n");
+                USB_sendstr(ans);
+                //if(ans[l-1] != '\n') usb_newline();
             }
         }
         if(usartrx()){ // usart1 received data, store in in buffer
             r = usart_getline(&txt);
             if(r){
                 txt[r] = 0;
-                ans = (char*)parse_cmd(txt);
+                ans = (char*)parse_cmd(usart_send, txt);
                 if(ans){
                     usart_send(ans);
                     transmit_tbuf();
                 }
-                USND("Got string over USART:\n");
+                USND("Got string over USART:");
                 USB_sendstr(txt);
             }
         }
diff --git a/F1:F103/F1_testbrd/pl2303.bin b/F1:F103/F1_testbrd/pl2303.bin
index 289405e..bf997e1 100755
Binary files a/F1:F103/F1_testbrd/pl2303.bin and b/F1:F103/F1_testbrd/pl2303.bin differ
diff --git a/F1:F103/F1_testbrd/proto.c b/F1:F103/F1_testbrd/proto.c
index 54f0124..6191b0d 100644
--- a/F1:F103/F1_testbrd/proto.c
+++ b/F1:F103/F1_testbrd/proto.c
@@ -29,15 +29,8 @@
 // local buffer for I2C and SPI data to send
 static uint8_t locBuffer[LOCBUFFSZ];
 
-void USB_sendstr(const char *str){
-    uint16_t l = 0;
-    const char *b = str;
-    while(*b++) ++l;
-    USB_send((const uint8_t*)str, l);
-}
-
-static inline char *chPWM(volatile uint32_t *reg, char *buf){
-    char *lbuf = buf;
+static inline const char *chPWM(volatile uint32_t *reg, const char *buf){
+    const char *lbuf = buf;
     lbuf = omit_spaces(lbuf);
     char cmd = *lbuf;
     lbuf = omit_spaces(lbuf + 1);
@@ -51,78 +44,50 @@ static inline char *chPWM(volatile uint32_t *reg, char *buf){
         if(oldval + N > 255) return "Already at maximum";
         else *reg += N;
     }else{
-        USND("Wrong command: ");
-        return buf;
+        return "Wrong command\n";
     }
     return "OK";
 }
 
-static inline char *TIM3pwm(char *buf){
+static inline const char *TIM3pwm(const char *buf){
     uint8_t channel = *buf - '1';
     if(channel > 3) return "Wrong channel number";
     volatile uint32_t *reg = (uint32_t*)&(TIM3->CCR1);
     return chPWM(&reg[channel], buf+1);
 }
 
-static inline char *getPWMvals(){
-    USND("TIM1CH1: "); USB_sendstr(u2str(TIM1->CCR1));
-    USND("\nTIM3CH1: "); USB_sendstr(u2str(TIM3->CCR1));
-    USND("\nTIM3CH2: "); USB_sendstr(u2str(TIM3->CCR2));
-    USND("\nTIM3CH3: "); USB_sendstr(u2str(TIM3->CCR3));
-    USND("\nTIM3CH4: "); USB_sendstr(u2str(TIM3->CCR4));
-    USND("\n");
+static inline char *getPWMvals(int (*sendfun)(const char *s)){
+    sendfun("TIM1CH1: "); sendfun(u2str(TIM1->CCR1));
+    sendfun("\nTIM3CH1: "); sendfun(u2str(TIM3->CCR1));
+    sendfun("\nTIM3CH2: "); sendfun(u2str(TIM3->CCR2));
+    sendfun("\nTIM3CH3: "); sendfun(u2str(TIM3->CCR3));
+    sendfun("\nTIM3CH4: "); sendfun(u2str(TIM3->CCR4));
+    sendfun("\n");
     return NULL;
 }
 
-static inline char *USARTsend(char *buf){
-//    uint32_t N;
-//    if(buf == getnum(buf, &N)) return "Point number of USART";
-//    if(N < 1 || N > USARTNUM) return "Wrong USART number";
-//    buf = omit_spaces(buf + 1);
+static inline const char *USARTsend(const char *buf){
     usart_send(buf);
     transmit_tbuf();
     return "OK";
 }
 
 // read N numbers from buf, @return 0 if wrong or none
-static uint16_t readNnumbers(char *buf){
+static uint16_t readNnumbers(int (*sendfun)(const char *s), const char *buf){
     uint32_t D;
-    char *nxt;
+    const char *nxt;
     uint16_t N = 0;
     while((nxt = getnum(buf, &D)) && nxt != buf && N < LOCBUFFSZ){
         buf = nxt;
         locBuffer[N++] = (uint8_t) D&0xff;
-        USND("add byte: "); USB_sendstr(uhex2str(D&0xff)); USND("\n");
+        sendfun("add byte: "); sendfun(uhex2str(D&0xff)); sendfun("\n");
     }
-    USND("Send "); USB_sendstr(u2str(N)); USND(" bytes\n");
+    sendfun("Send "); sendfun(u2str(N)); sendfun(" bytes\n");
     return N;
 }
 
-// dump memory buffer
-static void hexdump(uint8_t *arr, uint16_t len){
-    char buf[52], *bptr = buf;
-    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) *bptr++ = half + '0';
-            else *bptr++ = half - 10 + 'a';
-        }
-        if(l % 16 == 15){
-            *bptr++ = '\n';
-            *bptr = 0;
-            USB_sendstr(buf);
-            bptr = buf;
-        }else *bptr++ = ' ';
-    }
-    if(bptr != buf){
-        *bptr++ = '\n';
-        *bptr = 0;
-        USB_sendstr(buf);
-    }
-}
-
 static uint8_t i2cinited = 1;
-static inline char *setupI2C(char *buf){
+static inline const char *setupI2C(const char *buf){
     buf = omit_spaces(buf);
     if(*buf < '0' || *buf > '2') return "Wrong speed";
     i2c_setup(*buf - '0');
@@ -130,79 +95,79 @@ static inline char *setupI2C(char *buf){
     return "OK";
 }
 
-static inline char *saI2C(char *buf){
+static inline const char *saI2C(int (*sendfun)(const char *s), const char *buf){
     uint32_t addr;
     if(!getnum(buf, &addr) || addr > 0x7f) return "Wrong address";
-    USND("I2Caddr="); USB_sendstr(uhex2str(addr)); USND("\n");
+    sendfun("I2Caddr="); sendfun(uhex2str(addr)); sendfun("\n");
     i2c_set_addr7(addr);
     return "OK";
 }
-static inline void rdI2C(char *buf){
+static inline void rdI2C(int (*sendfun)(const char *s), const char *buf){
     uint32_t N;
-    char *nxt = getnum(buf, &N);
+    const char *nxt = getnum(buf, &N);
     if(!nxt || buf == nxt || N > 0xff){
-        USND("Bad register number\n");
+        sendfun("Bad register number\n");
         return;
     }
     buf = nxt;
     uint8_t reg = N;
     nxt = getnum(buf, &N);
     if(!nxt || buf == nxt || N > LOCBUFFSZ){
-        USND("Bad length\n");
+        sendfun("Bad length\n");
         return;
     }
     if(!read_i2c_reg(reg, locBuffer, N)){
-        USND("Error reading I2C\n");
+        sendfun("Error reading I2C\n");
         return;
     }
-    if(N == 0){ USND("OK"); return; }
-    USND("Register "); USB_sendstr(uhex2str(reg)); USND(":\n");
-    hexdump(locBuffer, N);
+    if(N == 0){ sendfun("OK\n"); return; }
+    sendfun("Register "); sendfun(uhex2str(reg)); sendfun(":\n");
+    hexdump(sendfun, locBuffer, N);
 }
-static inline char *wrI2C(char *buf){
-    uint16_t N = readNnumbers(buf);
+static inline const char *wrI2C(int (*sendfun)(const char *s), const char *buf){
+    uint16_t N = readNnumbers(sendfun, buf);
     if(!write_i2c(locBuffer, N)) return "Error writing I2C";
     if(N < 1) return "bad";
     return "OK";
 }
 
 // write locBuffer to SPI
-static inline void wrSPI(int SPIidx, char *buf){
+static inline void wrSPI(int (*sendfun)(const char *s), int SPIidx, const char *buf){
     if(SPIidx < 0 || SPIidx > 2) return;
-    uint16_t N = readNnumbers(buf);
+    uint16_t N = readNnumbers(sendfun, buf);
     if(N < 1){
         *(uint8_t *)&(SPI1->DR) = 0xea;
-        USND("Enter at least 1 number (max: ");
-        USB_sendstr(u2str(LOCBUFFSZ)); USND(")\n");
+        sendfun("Enter at least 1 number (max: ");
+        sendfun(u2str(LOCBUFFSZ)); sendfun(")\n");
         return;
     }
     //if(SPI_transmit(SPIidx, locBuffer, N)) USND("Error: busy?\n");
-    else USND("done");
+    else sendfun("done");
 }
-static inline void rdSPI(int SPIidx){
+static inline void rdSPI(int (*sendfun)(const char *s), int SPIidx){
     if(SPIidx < 0 || SPIidx > 2) return;
-    //if(SPI_isoverflow(SPIidx)) USND("SPI buffer overflow\n");
+    //if(SPI_isoverflow(SPIidx)) sendfun("SPI buffer overflow\n");
     uint8_t len = LOCBUFFSZ;
     /*
     if(SPI_getdata(SPIidx, locBuffer, &len)){
-        USND("Error getting data: busy?\n");
+        sendfun("Error getting data: busy?\n");
         return;
     }*/
     if(len == 0){
-        USND("Nothing to read\n");
+        sendfun("Nothing to read\n");
         return;
     }
-    if(len > LOCBUFFSZ) USND("Can't get full message: buffer too small\n");
-    USND("SPI data:\n");
-    hexdump(locBuffer, len);
+    if(len > LOCBUFFSZ) sendfun("Can't get full message: buffer too small\n");
+    sendfun("SPI data:\n");
+    hexdump(sendfun, locBuffer, len);
 }
 
-static inline char *procSPI(char *buf){
+static inline const char *procSPI(int (*sendfun)(const char *s), const char *buf){
     int idx = 0;
     if(*buf == 'p') idx = 1;
     buf = omit_spaces(buf + 1);
-    if(*buf == 'w')  wrSPI(idx, buf + 1);
-    else if(*buf == 'r') rdSPI(idx);
+    if(*buf == 'w')  wrSPI(sendfun, idx, buf + 1);
+    else if(*buf == 'r') rdSPI(sendfun, idx);
     else return "Enter `w` and data to write, `r` - to read";
     return NULL;
 }
@@ -228,24 +193,24 @@ const char *helpstring =
         "R - software reset\n"
         "S - send short string over USB\n"
         "s - setup SPI (and turn off USARTs)\n"
-        "Ux str - send string to USARTx (1..3)\n"
+        "U str - send string to USART1\n"
         "u - setup USARTs (and turn off SPI)\n"
         "T - MCU temperature\n"
         "V - Vdd\n"
         "W - test watchdog\n"
 ;
 
-void printADCvals(){
-    USND("AIN0: "); USB_sendstr(u2str(getADCval(0)));
-    USND(" ("); USB_sendstr(u2str(getADCvoltage(0)));
-    USND("/100 V)\nAIN1: "); USB_sendstr(u2str(getADCval(1)));
-    USND(" ("); USB_sendstr(u2str(getADCvoltage(1)));
-    USND("/100 V)\nAIN5: "); USB_sendstr(u2str(getADCval(2)));
-    USND(" ("); USB_sendstr(u2str(getADCvoltage(2)));
-    USND("/100 V)\n");
+void printADCvals(int (*sendfun)(const char *s)){
+    sendfun("AIN0: "); sendfun(u2str(getADCval(0)));
+    sendfun(" ("); sendfun(u2str(getADCvoltage(0)));
+    sendfun("/100 V)\nAIN1: "); sendfun(u2str(getADCval(1)));
+    sendfun(" ("); sendfun(u2str(getADCvoltage(1)));
+    sendfun("/100 V)\nAIN5: "); sendfun(u2str(getADCval(2)));
+    sendfun(" ("); sendfun(u2str(getADCvoltage(2)));
+    sendfun("/100 V)\n");
 }
 
-const char *parse_cmd(char *buf){
+const char *parse_cmd(int (*sendfun)(const char *s), const char *buf){
     // "long" commands
     switch(*buf){
         case '+':
@@ -266,15 +231,15 @@ const char *parse_cmd(char *buf){
         case 'I':
             if(!i2cinited) return "Init I2C first";
             buf = omit_spaces(buf + 1);
-            if(*buf == 'a') return saI2C(buf + 1);
-            else if(*buf == 'r'){ rdI2C(buf + 1); return NULL; }
-            else if(*buf == 'w') return wrI2C(buf + 1);
+            if(*buf == 'a') return saI2C(sendfun, buf + 1);
+            else if(*buf == 'r'){ rdI2C(sendfun, buf + 1); return NULL; }
+            else if(*buf == 'w') return wrI2C(sendfun, buf + 1);
             else if(*buf == 's'){ i2c_init_scan_mode(); return "Start scan\n";}
             else return "Command should be 'Ia', 'Iw', 'Ir' or 'Is'\n";
         break;
         case 'p':
         case 'P':
-            //return procSPI(buf);
+            //return procSPI(sendfun, buf);
             return "TODO";
         break;
         case 'U':
@@ -282,7 +247,7 @@ const char *parse_cmd(char *buf){
         break;
     }
     // "short" commands
-    if(buf[1] != '\n') return buf;
+    if(buf[1] && buf[1] != '\n') return buf;
     switch(*buf){
         case '0':
             pin_toggle(USBPU_port, USBPU_pin);
@@ -290,10 +255,10 @@ const char *parse_cmd(char *buf){
             else return "Pullup set";
         break;
         case 'g':
-            return getPWMvals();
+            return getPWMvals(sendfun);
         break;
         case 'A':
-            printADCvals();
+            printADCvals(sendfun);
         break;
         case 'L':
             USND("Very long test string for USB (it's length is more than 64 bytes).\n"
@@ -302,21 +267,21 @@ const char *parse_cmd(char *buf){
         break;
         case 'm':
             ADCmon = !ADCmon;
-            USND("Monitoring is ");
-            if(ADCmon) USND("on\n");
-            else USND("off\n");
+            sendfun("Monitoring is ");
+            if(ADCmon) sendfun("on\n");
+            else sendfun("off\n");
         break;
         case 'R':
-            USND("Soft reset\n");
+            USND("Soft reset");
             SEND("Soft reset\n");
             NVIC_SystemReset();
         break;
         case 'S':
-            USND("Test string for USB\n");
+            USND("Test string for USB");
             return "Short test sent";
         break;
         case 's':
-            USND("SPI are ON, USART are OFF\n");
+            sendfun("SPI are ON, USART are OFF\n");
             //usart_stop();
             //spi_setup();
         break;
@@ -342,205 +307,3 @@ const char *parse_cmd(char *buf){
     }
     return NULL;
 }
-
-// usb getline
-char *get_USB(){
-    static char tmpbuf[129], *curptr = tmpbuf;
-    static int rest = 128;
-    int x = USB_receive((uint8_t*)curptr);
-    curptr[x] = 0;
-    if(!x) return NULL;
-    if(curptr[x-1] == '\n'){
-        curptr = tmpbuf;
-        rest = 128;
-        return tmpbuf;
-    }
-    curptr += x; rest -= x;
-    if(rest <= 0){ // buffer overflow
-        curptr = tmpbuf;
-        rest = 128;
-    }
-    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);
-}
-// print 32bit unsigned int as hex
-char *uhex2str(uint32_t val){
-    static char buf[12] = "0x";
-    int npos = 2;
-    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) buf[npos++] = half + '0';
-            else buf[npos++] = half - 10 + 'a';
-        }
-    }
-    buf[npos] = 0;
-    return buf;
-}
-
-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;
-}
diff --git a/F1:F103/F1_testbrd/proto.h b/F1:F103/F1_testbrd/proto.h
index 28969c6..262f075 100644
--- a/F1:F103/F1_testbrd/proto.h
+++ b/F1:F103/F1_testbrd/proto.h
@@ -19,17 +19,11 @@
 #pragma once
 #include <stm32f1.h>
 
+#include "strfunc.h"
+
 extern volatile uint8_t ADCmon;
 
-void USB_sendstr(const char *str);
-char *get_USB();
-const char *parse_cmd(char *buf);
+const char *parse_cmd(int (*sendfun)(const char *s), const char *buf);
+void printADCvals(int (*sendfun)(const char *s));
 
-void printADCvals();
-
-char *u2str(uint32_t val);
-char *i2str(int32_t i);
-char *uhex2str(uint32_t val);
-char *getnum(const char *txt, uint32_t *N);
-char *omit_spaces(const char *buf);
 
diff --git a/F1:F103/F1_testbrd/ringbuffer.c b/F1:F103/F1_testbrd/ringbuffer.c
new file mode 100644
index 0000000..1974fc3
--- /dev/null
+++ b/F1:F103/F1_testbrd/ringbuffer.c
@@ -0,0 +1,124 @@
+/*
+ * This file is part of the F1_testbrd project.
+ * Copyright 2023 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 "ringbuffer.h"
+
+// stored data length
+int RB_datalen(ringbuffer *b){
+    if(b->tail >= b->head) return (b->tail - b->head);
+    else return (b->length - b->head + b->tail);
+}
+
+/**
+ * @brief RB_hasbyte - check if buffer has given byte stored
+ * @param b - buffer
+ * @param byte - byte to find
+ * @return index if found, -1 if none
+ */
+int RB_hasbyte(ringbuffer *b, uint8_t byte){
+    if(b->head == b->tail) return -1; // no data in buffer
+    int startidx = b->head;
+    if(b->head > b->tail){ //
+        for(int found = b->head; found < b->length; ++found)
+            if(b->data[found] == byte) return found;
+        startidx = 0;
+    }
+    for(int found = startidx; found < b->tail; ++found)
+        if(b->data[found] == byte) return found;
+    return -1;
+}
+
+// poor memcpy
+static void mcpy(uint8_t *targ, const uint8_t *src, int l){
+    while(l--) *targ++ = *src++;
+}
+
+// increment head or tail
+TRUE_INLINE void incr(ringbuffer *b, volatile int *what, int n){
+    *what += n;
+    if(*what >= b->length) *what -= b->length;
+}
+
+/**
+ * @brief RB_read - read data from ringbuffer
+ * @param b - buffer
+ * @param s - array to write data
+ * @param len - max len of `s`
+ * @return bytes read
+ */
+int RB_read(ringbuffer *b, uint8_t *s, int len){
+    int l = RB_datalen(b);
+    if(!l) return 0;
+    if(l > len) l = len;
+    int _1st = b->length - b->head;
+    if(_1st > l) _1st = l;
+    if(_1st > len) _1st = len;
+    mcpy(s, b->data + b->head, _1st);
+    if(_1st < len && l > _1st){
+        mcpy(s+_1st, b->data, l - _1st);
+        incr(b, &b->head, l);
+        return l;
+    }
+    incr(b, &b->head, _1st);
+    return _1st;
+}
+
+/**
+ * @brief RB_readto fill array `s` with data until byte `byte` (with it)
+ * @param b - ringbuffer
+ * @param byte - check byte
+ * @param s - buffer to write data
+ * @param len - length of `s`
+ * @return amount of bytes written (negative, if len<data in buffer)
+ */
+int RB_readto(ringbuffer *b, uint8_t byte, uint8_t *s, int len){
+    int idx = RB_hasbyte(b, byte);
+    if(idx < 0) return 0;
+    int partlen = idx + 1 - b->head;
+    // now calculate length of new data portion
+    if(idx < b->head) partlen += b->length;
+    if(partlen > len) return -RB_read(b, s, len);
+    return RB_read(b, s, partlen);
+}
+
+/**
+ * @brief RB_write - write some data to ringbuffer
+ * @param b - buffer
+ * @param str - data
+ * @param l - length
+ * @return amount of bytes written
+ */
+int RB_write(ringbuffer *b, const uint8_t *str, int l){
+    int r = b->length - 1 - RB_datalen(b); // rest length
+    if(l > r) l = r;
+    if(!l) return 0;
+    int _1st = b->length - b->tail;
+    if(_1st > l) _1st = l;
+    mcpy(b->data + b->tail, str, _1st);
+    if(_1st < l){ // add another piece from start
+        mcpy(b->data, str+_1st, l-_1st);
+    }
+    incr(b, &b->tail, l);
+    return l;
+}
+
+// just delete all information in buffer `b`
+void RB_clearbuf(ringbuffer *b){
+    b->head = 0;
+    b->tail = 0;
+}
diff --git a/F1:F103/F1_testbrd/ringbuffer.h b/F1:F103/F1_testbrd/ringbuffer.h
new file mode 100644
index 0000000..3ab5ae1
--- /dev/null
+++ b/F1:F103/F1_testbrd/ringbuffer.h
@@ -0,0 +1,35 @@
+/*
+ * This file is part of the F1_testbrd project.
+ * Copyright 2023 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
+#include <stm32f1.h>
+
+typedef struct{
+    uint8_t *data;      // data buffer
+    const int length;   // its length
+    int head;           // head index
+    int tail;           // tail index
+} ringbuffer;
+
+int RB_read(ringbuffer *b, uint8_t *s, int len);
+int RB_readto(ringbuffer *b, uint8_t byte, uint8_t *s, int len);
+int RB_hasbyte(ringbuffer *b, uint8_t byte);
+int RB_write(ringbuffer *b, const uint8_t *str, int l);
+int RB_datalen(ringbuffer *b);
+void RB_clearbuf(ringbuffer *b);
+
diff --git a/F1:F103/F1_testbrd/strfunc.c b/F1:F103/F1_testbrd/strfunc.c
new file mode 100644
index 0000000..25d1d54
--- /dev/null
+++ b/F1:F103/F1_testbrd/strfunc.c
@@ -0,0 +1,267 @@
+/*
+ * This file is part of the F1_testbrd project.
+ * Copyright 2023 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>
+#include <string.h>
+/**
+ * @brief hexdump - dump hex array by 16 bytes in string
+ * @param sendfun - function to send data
+ * @param arr - array to dump
+ * @param len - length of `arr`
+ */
+void hexdump(int (*sendfun)(const char *s), uint8_t *arr, uint16_t len){
+    char buf[52], *bptr = buf;
+    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) *bptr++ = half + '0';
+            else *bptr++ = half - 10 + 'a';
+        }
+        if(l % 16 == 15){
+            *bptr++ = '\n';
+            *bptr = 0;
+            sendfun(buf);
+            bptr = buf;
+        }else *bptr++ = ' ';
+    }
+    if(bptr != buf){
+        *bptr++ = '\n';
+        *bptr = 0;
+        sendfun(buf);
+    }
+}
+
+/**
+ * @brief _2str - convert value into string buffer
+ * @param val - |value|
+ * @param minus - ==0 if value > 0
+ * @return buffer with number
+ */
+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){
+            uint32_t x = val / 10;
+            *(--bufptr) = (val - 10*x) + '0';
+            val = x;
+            //*(--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);
+}
+
+/**
+ * @brief uhex2str - print 32bit unsigned int as hex
+ * @param val - value
+ * @return string with number
+ */
+char *uhex2str(uint32_t val){
+    static char buf[12] = "0x";
+    int npos = 2;
+    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) buf[npos++] = half + '0';
+            else buf[npos++] = half - 10 + 'a';
+        }
+    }
+    buf[npos] = 0;
+    return buf;
+}
+
+/**
+ * @brief omit_spaces - eliminate leading spaces and other trash in string
+ * @param buf - string
+ * @return - pointer to first character in `buf` > ' '
+ */
+const char *omit_spaces(const char *buf){
+    while(*buf){
+        if(*buf > ' ') break;
+        ++buf;
+    }
+    return buf;
+}
+
+/**
+ * @brief getdec - read decimal number & return pointer to next non-number symbol
+ * @param buf - string
+ * @param N - number read
+ * @return Next non-number symbol. In case of overflow return `buf` and N==0xffffffff
+ */
+static const 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 buf;
+}
+// read hexadecimal number (without 0x prefix!)
+static const char *gethex(const char *buf, uint32_t *N){
+    const char *start = 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 buf;
+}
+// read octal number (without 0 prefix!)
+static const char *getoct(const char *buf, uint32_t *N){
+    const 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 buf;
+}
+// read binary number (without b prefix!)
+static const char *getbin(const char *buf, uint32_t *N){
+    const 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 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)
+ */
+const char *getnum(const char *txt, uint32_t *N){
+    const char *nxt = NULL;
+    const 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;
+}
+
+// get signed integer
+const char *getint(const char *txt, int32_t *I){
+    const char *s = omit_spaces(txt);
+    int32_t sign = 1;
+    uint32_t U;
+    if(*s == '-'){
+    	sign = -1;
+    	++s;
+    }
+    const char *nxt = getnum(s, &U);
+    if(nxt == s) return txt;
+    if(U & 0x80000000) return txt; // overfull
+    *I = sign * (int32_t)U;
+    return nxt;
+}
diff --git a/F1:F103/F1_testbrd/strfunc.h b/F1:F103/F1_testbrd/strfunc.h
new file mode 100644
index 0000000..4375e23
--- /dev/null
+++ b/F1:F103/F1_testbrd/strfunc.h
@@ -0,0 +1,30 @@
+/*
+ * This file is part of the F1_testbrd project.
+ * Copyright 2023 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
+
+#include <stdint.h>
+#include <string.h>
+
+void hexdump(int (*sendfun)(const char *s), uint8_t *arr, uint16_t len);
+const char *u2str(uint32_t val);
+const char *i2str(int32_t i);
+const char *uhex2str(uint32_t val);
+const char *getnum(const char *txt, uint32_t *N);
+const char *omit_spaces(const char *buf);
+const char *getint(const char *txt, int32_t *I);
diff --git a/F1:F103/F1_testbrd/usart.c b/F1:F103/F1_testbrd/usart.c
index 679ae7e..b06fb51 100644
--- a/F1:F103/F1_testbrd/usart.c
+++ b/F1:F103/F1_testbrd/usart.c
@@ -72,17 +72,20 @@ void usart_putchar(const char ch){
     tbuf[tbufno][odatalen[tbufno]++] = ch;
 }
 
-void usart_send(const char *str){
+int usart_send(const char *str){
+    int l = 0;
     while(*str){
         if(odatalen[tbufno] == UARTBUFSZO){
             transmit_tbuf();
             continue;
         }
         tbuf[tbufno][odatalen[tbufno]++] = *str++;
+        ++l;
     }
+    return l;
 }
 
-void newline(){
+void usart_newline(){
     usart_putchar('\n');
     transmit_tbuf();
 }
diff --git a/F1:F103/F1_testbrd/usart.h b/F1:F103/F1_testbrd/usart.h
index 13d1042..692a7db 100644
--- a/F1:F103/F1_testbrd/usart.h
+++ b/F1:F103/F1_testbrd/usart.h
@@ -49,7 +49,7 @@ 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();
+int usart_send(const char *str);
+void usart_newline();
 void usart_putchar(const char ch);
 
diff --git a/F1:F103/F1_testbrd/usb.c b/F1:F103/F1_testbrd/usb.c
index 7380bde..1ee69d7 100644
--- a/F1:F103/F1_testbrd/usb.c
+++ b/F1:F103/F1_testbrd/usb.c
@@ -1,6 +1,6 @@
 /*
  * This file is part of the F1_testbrd project.
- * Copyright 2022 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ * Copyright 2023 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
@@ -16,153 +16,111 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "usart.h"
+#include <string.h>
+
+#include "hardware.h"
 #include "usb.h"
 #include "usb_lib.h"
 
-#ifdef DBG
-#undef DBG
-#define DBG(x)
-#endif
+static volatile uint8_t usbbuff[USB_TXBUFSZ]; // temporary buffer for sending data
+// ring buffers for incoming and outgoing data
+static uint8_t obuf[RBOUTSZ], ibuf[RBINSZ];
+volatile ringbuffer rbout = {.data = obuf, .length = RBOUTSZ, .head = 0, .tail = 0};
+volatile ringbuffer rbin = {.data = ibuf, .length = RBINSZ, .head = 0, .tail = 0};
+// transmission is succesfull
+volatile uint8_t bufisempty = 1;
+volatile uint8_t bufovrfl = 0;
 
-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);
+void send_next(){
+    if(bufisempty) return;
+    static int lastdsz = 0;
+    int buflen = RB_read((ringbuffer*)&rbout, (uint8_t*)usbbuff, USB_TXBUFSZ);
+    if(!buflen){
+        if(lastdsz == 64) EP_Write(3, NULL, 0); // send ZLP after 64 bits packet when nothing more to send
+        lastdsz = 0;
+        bufisempty = 1;
         return;
     }
-    while(len--) usbbuff[buflen++] = *buf++;
+    EP_Write(3, (uint8_t*)usbbuff, buflen);
+    lastdsz = buflen;
 }
 
-// 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;
+// blocking send full content of ring buffer
+int USB_sendall(){
+    while(!bufisempty){
+        if(!usbON) return 0;
     }
-    int needzlp = 0;
+    return 1;
+}
+
+// put `buf` into queue to send
+int USB_send(const uint8_t *buf, int len){
+    if(!buf || !usbON || !len) return 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);
+        int a = RB_write((ringbuffer*)&rbout, buf, len);
+        len -= a;
+        buf += a;
+        if(bufisempty){
+            bufisempty = 0;
+            send_next();
+        }
     }
+    return 1;
 }
 
-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;
+int USB_putbyte(uint8_t byte){
+    if(!usbON) return 0;
+    while(0 == RB_write((ringbuffer*)&rbout, &byte, 1)){
+        if(bufisempty){
+            bufisempty = 0;
             send_next();
+        }
     }
+    return 1;
+}
+
+int USB_sendstr(const char *string){
+    if(!string || !usbON) return 0;
+    int len = 0;
+    const char *b = string;
+    while(*b++) ++len;
+    if(!len) return 0;
+    return USB_send((const uint8_t*)string, len);
 }
 
 /**
- * @brief USB_receive
- * @param buf (i) - buffer[64] for received data
- * @return amount of received bytes
+ * @brief USB_receive - get binary data from receiving ring-buffer
+ * @param buf (i) - buffer for received data
+ * @param len - length of `buf`
+ * @return amount of received bytes (negative, if overfull happened)
  */
-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;
+int USB_receive(uint8_t *buf, int len){
+    int sz = RB_read((ringbuffer*)&rbin, buf, len);
+    if(bufovrfl){
+        RB_clearbuf((ringbuffer*)&rbin);
+        if(!sz) sz = -1;
+        else sz = -sz;
+        bufovrfl = 0;
+    }
     return sz;
 }
+
+/**
+ * @brief USB_receivestr - get string up to '\n' and replace '\n' with 0
+ * @param buf - receiving buffer
+ * @param len - its length
+ * @return strlen or negative value indicating overflow (if so, string won't be ends with 0 and buffer should be cleared)
+ */
+int USB_receivestr(char *buf, int len){
+    int l = RB_readto((ringbuffer*)&rbin, '\n', (uint8_t*)buf, len);
+    if(l == 0) return 0;
+    if(--l < 0 || bufovrfl) RB_clearbuf((ringbuffer*)&rbin);
+    else buf[l] = 0; // replace '\n' with strend
+    if(bufovrfl){
+        if(l > 0) l = -l;
+        else l = -1;
+        bufovrfl = 0;
+    }
+    return l;
+}
+
diff --git a/F1:F103/F1_testbrd/usb.h b/F1:F103/F1_testbrd/usb.h
index 27070c6..c23dbce 100644
--- a/F1:F103/F1_testbrd/usb.h
+++ b/F1:F103/F1_testbrd/usb.h
@@ -1,6 +1,6 @@
 /*
  * This file is part of the F1_testbrd project.
- * Copyright 2022 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ * Copyright 2023 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
@@ -17,14 +17,33 @@
  */
 
 #pragma once
-#include "hardware.h"
+#include "ringbuffer.h"
+#include "usbhw.h"
 
-#define BUFFSIZE   (64)
+// sizes of ringbuffers for outgoing and incoming data
+#define RBOUTSZ     (512)
+#define RBINSZ      (512)
 
-#define USND(str)  do{USB_send((uint8_t*)str, sizeof(str)-1);}while(0)
+#define usb_newline()   USB_putbyte('\n')
+#define USND(s)         do{USB_sendstr(s); USB_putbyte('\n');}while(0)
 
-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);
+#if 0
+#define STR_HELPER(s)   #s
+#define STR(s)          STR_HELPER(s)
+#ifdef EBUG
+#define DBG(str)  do{USB_sendstr(__FILE__ " (L" STR(__LINE__) "): " str); newline();}while(0)
+#else
+#define DBG(str)
+#endif
+#endif
+
+extern volatile ringbuffer rbout, rbin;
+extern volatile uint8_t bufisempty, bufovrfl;
+
+void send_next();
+int USB_sendall();
+int USB_send(const uint8_t *buf, int len);
+int USB_putbyte(uint8_t byte);
+int USB_sendstr(const char *string);
+int USB_receive(uint8_t *buf, int len);
+int USB_receivestr(char *buf, int len);
diff --git a/F1:F103/F1_testbrd/usb_lib.c b/F1:F103/F1_testbrd/usb_lib.c
index 20d5633..f96d67a 100644
--- a/F1:F103/F1_testbrd/usb_lib.c
+++ b/F1:F103/F1_testbrd/usb_lib.c
@@ -1,6 +1,6 @@
 /*
  * This file is part of the F1_testbrd project.
- * Copyright 2022 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ * Copyright 2023 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
@@ -17,19 +17,20 @@
  */
 
 #include <stdint.h>
+#include "usb.h"
 #include "usb_lib.h"
+#include "usbhw.h"
 
 ep_t endpoints[STM32ENDPOINTS];
 
-usb_dev_t USB_Dev;
+static uint16_t USB_Addr = 0;
 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;
+uint8_t ep0databuf[EP0DATABUF_SIZE], setupdatabuf[EP0DATABUF_SIZE];
+static config_pack_t *setup_packet = (config_pack_t*) setupdatabuf;
 
 usb_LineCoding getLineCoding(){return lineCoding;}
 
-uint8_t usbON = 0; // device disconnected from terminal
+volatile uint8_t usbON = 0; // device disconnected from terminal
 
 // definition of parts common for USB_DeviceDescriptor & USB_DeviceQualifierDescriptor
 #define bcdUSB_L        0x10
@@ -54,9 +55,9 @@ static const uint8_t USB_DeviceDescriptor[] = {
         0x23,   // idProduct_H
         0x00,   // bcdDevice_Ver_L
         0x03,   // bcdDevice_Ver_H
-        0x01,   // iManufacturer
-        0x02,   // iProduct
-        0x00,   // iSerialNumber
+        iMANUFACTURER_DESCR,   // iManufacturer
+        iPRODUCT_DESCR,   // iProduct
+        iSERIAL_DESCR,   // iSerialNumber
         bNumConfigurations    // bNumConfigurations
 };
 
@@ -96,7 +97,7 @@ static const uint8_t USB_ConfigDescriptor[] = {
         0xff, /* bInterfaceClass */
         0x00, /* bInterfaceSubClass */
         0x00, /* bInterfaceProtocol */
-        0x00, /* iInterface: */
+        iINTERFACE_DESCR, /* iInterface: */
 ///////////////////////////////////////////////////
         /*Endpoint 1 Descriptor*/
         0x07, /* bLength: Endpoint Descriptor size */
@@ -126,11 +127,19 @@ static const uint8_t USB_ConfigDescriptor[] = {
         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");
+_USB_LANG_ID_(LD, LANG_US);
+_USB_STRING_(SD, u"0.0.1");
+_USB_STRING_(MD, u"Prolific Technology Inc.");
+_USB_STRING_(PD, u"USB-Serial Controller");
+_USB_STRING_(ID, u"pl2303_emulator");
+static void const *StringDescriptor[iDESCR_AMOUNT] = {
+    [iLANGUAGE_DESCR] = &LD,
+    [iMANUFACTURER_DESCR] = &MD,
+    [iPRODUCT_DESCR] = &PD,
+    [iSERIAL_DESCR] = &SD,
+    [iINTERFACE_DESCR] = &ID
+};
+
 
 /*
  * default handlers
@@ -149,8 +158,8 @@ void WEAK break_handler(){
 
 // handler of vendor requests
 void WEAK vendor_handler(config_pack_t *packet){
+    uint16_t c;
     if(packet->bmRequestType & 0x80){ // read
-        uint8_t c;
         switch(packet->wValue){
             case 0x8484:
                 c = 2;
@@ -164,14 +173,15 @@ void WEAK vendor_handler(config_pack_t *packet){
             default:
                 c = 0;
         }
-        EP_WriteIRQ(0, &c, 1);
+        EP_WriteIRQ(0, (uint8_t*)&c, 1);
     }else{ // write ZLP
-        EP_WriteIRQ(0, (uint8_t *)0, 0);
+        c = 0;
+        EP_WriteIRQ(0, (uint8_t *)&c, 0);
     }
 }
 
 static void wr0(const uint8_t *buf, uint16_t size){
-    if(setup_packet.wLength < size) size = setup_packet.wLength; // shortened request
+    if(setup_packet->wLength < size) size = setup_packet->wLength; // shortened request
     if(size < endpoints[0].txbufsz){
         EP_WriteIRQ(0, buf, size);
         return;
@@ -199,24 +209,18 @@ static void wr0(const uint8_t *buf, uint16_t size){
 }
 
 static inline void get_descriptor(){
-    switch(setup_packet.wValue){
+    uint8_t descrtype = setup_packet->wValue >> 8,
+            descridx = setup_packet->wValue & 0xff;
+    switch(descrtype){
         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);
+        case STRING_DESCRIPTOR:
+            if(descridx < iDESCR_AMOUNT) wr0((const uint8_t *)StringDescriptor[descridx], *((uint8_t*)StringDescriptor[descridx]));
+            else EP_WriteIRQ(0, (uint8_t*)0, 0);
         break;
         case DEVICE_QUALIFIER_DESCRIPTOR:
             wr0(USB_DeviceQualifierDescriptor, USB_DeviceQualifierDescriptor[0]);
@@ -226,10 +230,10 @@ static inline void get_descriptor(){
     }
 }
 
-static uint8_t configuration = 0; // reply for GET_CONFIGURATION (==1 if configured)
+static uint16_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){
+    switch(setup_packet->bRequest){
         case GET_DESCRIPTOR:
             get_descriptor();
         break;
@@ -237,23 +241,54 @@ static inline void std_d2h_req(){
             EP_WriteIRQ(0, (uint8_t *)&status, 2); // send status: Bus Powered
         break;
         case GET_CONFIGURATION:
-            EP_WriteIRQ(0, &configuration, 1);
+            EP_WriteIRQ(0, (uint8_t*)&configuration, 1);
         break;
         default:
         break;
     }
 }
 
+// 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
+    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
+    send_next();
+}
+
+static void receive_Handler(){ // EP2OUT
+    uint8_t buf[USB_RXBUFSZ];
+    uint16_t epstatus = KEEP_DTOG(USB->EPnR[2]);
+    uint8_t sz = EP_Read(2, (uint8_t*)buf);
+    if(sz){
+        if(RB_write((ringbuffer*)&rbin, buf, sz) != sz) bufovrfl = 1;
+    }
+    // keep stat_tx & set ACK rx, clear RX ctr
+    USB->EPnR[2] = (epstatus & ~USB_EPnR_CTR_RX) ^ USB_EPnR_STAT_RX;
+}
+
 static inline void std_h2d_req(){
-    switch(setup_packet.bRequest){
+    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;
+            USB_Addr = setup_packet->wValue;
         break;
         case SET_CONFIGURATION:
             // Now device configured
-            USB_Dev.USB_Status = USB_STATE_CONFIGURED;
-            configuration = setup_packet.wValue;
+            configuration = setup_packet->wValue;
+            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
         break;
         default:
         break;
@@ -269,10 +304,10 @@ bmRequestType: 76543210
 /**
  * Endpoint0 (control) handler
  */
-static void EP0_Handler(){
+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;
+    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){
@@ -285,15 +320,15 @@ static void EP0_Handler(){
                 }
             break;
             case STANDARD_ENDPOINT_REQUEST_TYPE: // standard endpoint request
-                if(setup_packet.bRequest == CLEAR_FEATURE){
+                if(setup_packet->bRequest == CLEAR_FEATURE){
                     EP_WriteIRQ(0, (uint8_t *)0, 0);
                 }
             break;
             case VENDOR_REQUEST_TYPE:
-                vendor_handler(&setup_packet);
+                vendor_handler(setup_packet);
             break;
             case CONTROL_REQUEST_TYPE:
-                switch(setup_packet.bRequest){
+                switch(setup_packet->bRequest){
                     case GET_LINE_CODING:
                         EP_WriteIRQ(0, (uint8_t*)&lineCoding, sizeof(lineCoding));
                     break;
@@ -301,7 +336,7 @@ static void EP0_Handler(){
                     break;
                     case SET_CONTROL_LINE_STATE:
                         usbON = 1;
-                        clstate_handler(setup_packet.wValue);
+                        clstate_handler(setup_packet->wValue);
                     break;
                     case SEND_BREAK:
                         usbON = 0;
@@ -310,23 +345,22 @@ static void EP0_Handler(){
                     default:
                     break;
                 }
-                if(setup_packet.bRequest != GET_LINE_CODING) EP_WriteIRQ(0, (uint8_t *)0, 0); // write acknowledgement
+                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){
+            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;
+        if ((USB->DADDR & USB_DADDR_ADD) != USB_Addr){
+            USB->DADDR = USB_DADDR_EF | USB_Addr;
+            usbON = 0;
         }
     }
     epstatus = KEEP_DTOG(USB->EPnR[0]);
@@ -336,95 +370,6 @@ static void EP0_Handler(){
     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
@@ -432,15 +377,24 @@ void usb_lp_can_rx0_isr(){
  * @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;
+#if defined USB1_16
+    // very bad: what if `size` is odd?
     uint32_t *out = (uint32_t *)endpoints[number].tx_buf;
-    for(i = 0; i < N2; ++i, ++out){
+    for(int i = 0; i < N2; ++i, ++out){
         *out = buf16[i];
     }
+#elif defined USB2_16
+    // use memcpy instead?
+    for(int i = 0; i < N2; i++){
+        endpoints[number].tx_buf[i] = buf16[i];
+    }
+#else
+#error "Define USB1_16 or USB2_16"
+#endif
     USB_BTABLE->EP[number].USB_COUNT_TX = size;
 }
 
@@ -462,16 +416,23 @@ void EP_Write(uint8_t number, const uint8_t *buf, uint16_t size){
  * @param *buf - user array for data
  * @return amount of data read
  */
-int EP_Read(uint8_t number, uint16_t *buf){
+int EP_Read(uint8_t number, uint8_t *buf){
     int sz = endpoints[number].rx_cnt;
     if(!sz) return 0;
     endpoints[number].rx_cnt = 0;
+#if defined USB1_16
     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;
-    }
+    uint32_t *in = (uint32_t*)endpoints[number].rx_buf;
+    uint16_t *out = (uint16_t*)buf;
+    for(int i = 0; i < n; ++i, ++in)
+        out[i] = *(uint16_t*)in;
+#elif defined USB2_16
+    // use memcpy instead?
+    for(int i = 0; i < sz; ++i)
+        buf[i] = endpoints[number].rx_buf[i];
+#else
+#error "Define USB1_16 or USB2_16"
+#endif
     return sz;
 }
 
diff --git a/F1:F103/F1_testbrd/usb_lib.h b/F1:F103/F1_testbrd/usb_lib.h
index f938b85..9d68798 100644
--- a/F1:F103/F1_testbrd/usb_lib.h
+++ b/F1:F103/F1_testbrd/usb_lib.h
@@ -1,6 +1,6 @@
 /*
  * This file is part of the F1_testbrd project.
- * Copyright 2022 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ * Copyright 2023 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
@@ -18,7 +18,7 @@
 
 #pragma once
 #include <wchar.h>
-#include "usb_defs.h"
+#include "usbhw.h"
 
 #define EP0DATABUF_SIZE                 (64)
 #define LASTADDR_DEFAULT                (STM32ENDPOINTS * 8)
@@ -59,14 +59,21 @@
 #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
+// string descriptors
+enum{
+    iLANGUAGE_DESCR,
+    iMANUFACTURER_DESCR,
+    iPRODUCT_DESCR,
+    iSERIAL_DESCR,
+    iINTERFACE_DESCR,
+    iDESCR_AMOUNT
+};
+
+// Types of descriptors
+#define DEVICE_DESCRIPTOR               0x01
+#define CONFIGURATION_DESCRIPTOR        0x02
+#define STRING_DESCRIPTOR               0x03
+#define DEVICE_QUALIFIER_DESCRIPTOR     0x06
 
 #define RX_FLAG(epstat)                 (epstat & USB_EPnR_CTR_RX)
 #define TX_FLAG(epstat)                 (epstat & USB_EPnR_CTR_TX)
@@ -76,14 +83,6 @@
 #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
@@ -112,7 +111,6 @@ static const struct name \
     \
 } \
 name = {0x04, 0x03, lng_id}
-#define STRING_LANG_DESCRIPTOR_SIZE_BYTE    (4)
 
 // EP0 configuration packet
 typedef struct {
@@ -127,17 +125,11 @@ typedef struct {
 typedef struct{
     uint16_t *tx_buf;           // transmission buffer address
     uint16_t txbufsz;           // transmission buffer size
-    uint16_t *rx_buf;           // reception buffer address
+    uint8_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;
@@ -162,15 +154,14 @@ typedef struct {
 } __attribute__ ((packed)) usb_cdc_notification;
 
 extern ep_t endpoints[];
-extern usb_dev_t USB_Dev;
-extern uint8_t usbON;
+extern volatile uint8_t usbON;
+extern uint8_t ep0databuf[], setupdatabuf[];
+
+void EP0_Handler();
 
-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);
+int EP_Read(uint8_t number, uint8_t *buf);
 usb_LineCoding getLineCoding();
 
 void linecoding_handler(usb_LineCoding *lc);
diff --git a/F1:F103/F1_testbrd/usbhw.c b/F1:F103/F1_testbrd/usbhw.c
new file mode 100644
index 0000000..42668e5
--- /dev/null
+++ b/F1:F103/F1_testbrd/usbhw.c
@@ -0,0 +1,123 @@
+/*
+ * This file is part of the F1_testbrd project.
+ * Copyright 2023 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 "usbhw.h"
+#include "usb_lib.h"
+
+void USB_setup(){
+    NVIC_DisableIRQ(USB_LP_CAN1_RX0_IRQn);
+    NVIC_DisableIRQ(USB_HP_CAN1_TX_IRQn);
+    USBPU_OFF();
+    RCC->APB1ENR |= RCC_APB1ENR_USBEN;
+    RCC->APB2ENR |= USB_RCC;
+    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);
+    USBPU_ON();
+}
+
+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 * ACCESSZ);
+    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 = (uint8_t *)(USB_BTABLE_BASE + lastaddr * ACCESSZ);
+    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;
+        // 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;
+        if(EP_Init(0, EP_TYPE_CONTROL, USB_EP0_BUFSZ, USB_EP0_BUFSZ, EP0_Handler)){
+            return;
+        }
+        USB->ISTR = ~USB_ISTR_RESET;
+    }
+    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, setupdatabuf);
+                    // interrupt handler will be called later
+                }else if(epstatus & USB_EPnR_CTR_RX){ // data packet -> push received data to ep0databuf
+                    EP_Read(0, 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;
+    }
+}
diff --git a/F1:F103/F1_testbrd/usb_defs.h b/F1:F103/F1_testbrd/usbhw.h
similarity index 82%
rename from F1:F103/F1_testbrd/usb_defs.h
rename to F1:F103/F1_testbrd/usbhw.h
index 0b98f02..4c2fd04 100644
--- a/F1:F103/F1_testbrd/usb_defs.h
+++ b/F1:F103/F1_testbrd/usbhw.h
@@ -1,6 +1,6 @@
 /*
  * This file is part of the F1_testbrd project.
- * Copyright 2022 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ * Copyright 2023 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
@@ -19,14 +19,18 @@
 #pragma once
 #include <stm32f1.h>
 
+#define USB_RCC     RCC_APB2ENR_IOPAEN
+#define USBPU_port  GPIOA
+#define USBPU_pin   (1<<15)
+#define USBPU_ON()  pin_clear(USBPU_port, USBPU_pin)
+#define USBPU_OFF() pin_set(USBPU_port, USBPU_pin)
+
 // 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)
@@ -71,9 +75,7 @@
 #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];
@@ -86,12 +88,28 @@ typedef struct {
 } USB_TypeDef;
 
 typedef struct{
+#if defined USB2_16
+    __IO uint16_t USB_ADDR_TX;
+    __IO uint16_t USB_COUNT_TX;
+    __IO uint16_t USB_ADDR_RX;
+    __IO uint16_t USB_COUNT_RX;
+#define ACCESSZ (1)
+#define BUFTYPE uint8_t
+#elif defined USB1_16
     __IO uint32_t USB_ADDR_TX;
     __IO uint32_t USB_COUNT_TX;
     __IO uint32_t USB_ADDR_RX;
     __IO uint32_t USB_COUNT_RX;
+#define ACCESSZ (2)
+#define BUFTYPE uint16_t
+#else
+#error "Define USB1_16 or USB2_16"
+#endif
 } USB_EPDATA_TypeDef;
 
 typedef struct{
     __IO USB_EPDATA_TypeDef EP[STM32ENDPOINTS];
 } USB_BtableDef;
+
+void USB_setup();
+int EP_Init(uint8_t number, uint8_t type, uint16_t txsz, uint16_t rxsz, void (*func)());
diff --git a/F1:F103/F1_testbrd/version.inc b/F1:F103/F1_testbrd/version.inc
new file mode 100644
index 0000000..3680a40
--- /dev/null
+++ b/F1:F103/F1_testbrd/version.inc
@@ -0,0 +1,2 @@
+#define BUILD_NUMBER "22"
+#define BUILD_DATE "2023-06-11"
diff --git a/F1:F103/PL2303_ringbuffer/Makefile b/F1:F103/PL2303_ringbuffer/Makefile
index d24a3a8..b3cf7a9 100644
--- a/F1:F103/PL2303_ringbuffer/Makefile
+++ b/F1:F103/PL2303_ringbuffer/Makefile
@@ -1,9 +1,9 @@
 BINARY      := PL2303
 # MCU code
-MCU         ?= F103x8
+MCU         ?= F103x6
 # change this linking script depending on particular MCU model,
-LDSCRIPT    ?= stm32f103x8.ld
-DEFINES     := -DSTM32F10X_MD
+LDSCRIPT    ?= stm32f103x6.ld
+DEFINES := -DUSB1_16 -DSTM32F10X_LD
 
 include ../makefile.f1
 include ../../makefile.stm32
diff --git a/F1:F103/PL2303_ringbuffer/Makefile.old b/F1:F103/PL2303_ringbuffer/Makefile.old
deleted file mode 100644
index 1d3be00..0000000
--- a/F1:F103/PL2303_ringbuffer/Makefile.old
+++ /dev/null
@@ -1,151 +0,0 @@
-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
-
-# autoincremental version & build date
-VERSION_FILE = version.inc
-NEXTVER := $(shell expr $$(awk '/#define BUILD_NUMBER/' $(VERSION_FILE) | tr -cd "[0-9]") + 1)
-BUILDDATE := $(shell date +%Y-%m-%d)
-
-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 -g -gdwarf-2
-CFLAGS		+= -Wall -Werror -Wextra -Wshadow 
-CFLAGS		+= -fno-common -ffunction-sections -fdata-sections -fno-stack-protector -fshort-enums 
-CFLAGS		+=  $(ARCH_FLAGS)
-
-###############################################################################
-# Linker flags
-LDFLAGS		+= -nostartfiles --static --gc-sections --print-memory-usage -specs=nano.specs 
-LDFLAGS		+= -L$(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 $<
-
-$(VERSION_FILE): *.[ch]
-	@echo "  Generate version: $(NEXTVER) for date $(BUILDDATE)"
-	@sed -i "s/#define BUILD_NUMBER.*/#define BUILD_NUMBER \"$(NEXTVER)\"/" $(VERSION_FILE)
-	@sed -i "s/#define BUILD_DATE.*/#define BUILD_DATE \"$(BUILDDATE)\"/" $(VERSION_FILE)
-
-$(OBJDIR)/proto.o: proto.c $(VERSION_FILE)
-
-$(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
diff --git a/F1:F103/PL2303_ringbuffer/PL2303.bin b/F1:F103/PL2303_ringbuffer/PL2303.bin
index ece1e8a..615b166 100755
Binary files a/F1:F103/PL2303_ringbuffer/PL2303.bin and b/F1:F103/PL2303_ringbuffer/PL2303.bin differ
diff --git a/F1:F103/PL2303_ringbuffer/hardware.c b/F1:F103/PL2303_ringbuffer/hardware.c
index 1df824e..7a78b04 100644
--- a/F1:F103/PL2303_ringbuffer/hardware.c
+++ b/F1:F103/PL2303_ringbuffer/hardware.c
@@ -19,13 +19,15 @@
 #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_IOPBEN | RCC_APB2ENR_IOPCEN | RCC_APB2ENR_AFIOEN;
+    // Enable clocks to the GPIO subsystems, 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);
+    //GPIOC->CRH |= CRH(13, CNF_ODOUTPUT | MODE_SLOW);
+    // USB pullup (PA15) - pushpull output
+    GPIOA->CRH = CRH(8, CNF_PPOUTPUT | MODE_SLOW) | CRH(15, CNF_PPOUTPUT | MODE_SLOW);
 }
 
 void hw_setup(){
diff --git a/F1:F103/PL2303_ringbuffer/hardware.h b/F1:F103/PL2303_ringbuffer/hardware.h
index d0955cf..2763e34 100644
--- a/F1:F103/PL2303_ringbuffer/hardware.h
+++ b/F1:F103/PL2303_ringbuffer/hardware.h
@@ -17,14 +17,13 @@
  */
 
 #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)
+// PA8 - my board
+#define LED0_port   GPIOA
+#define LED0_pin    (1<<8)
 
 #define LED_blink(x)    pin_toggle(x ## _port, x ## _pin)
 #define LED_on(x)       pin_clear(x ## _port, x ## _pin)
@@ -34,4 +33,3 @@ extern volatile uint32_t Tms;
 
 void hw_setup();
 
-#endif // __HARDWARE_H__
diff --git a/F1:F103/PL2303_ringbuffer/main.c b/F1:F103/PL2303_ringbuffer/main.c
index 2ab42e5..846aeb0 100644
--- a/F1:F103/PL2303_ringbuffer/main.c
+++ b/F1:F103/PL2303_ringbuffer/main.c
@@ -21,7 +21,7 @@
 #include "usart.h"
 #include "usb.h"
 
-#define USBBUFSZ    127
+#define MAXSTRLEN    RBINSZ
 
 volatile uint32_t Tms = 0;
 
@@ -29,34 +29,16 @@ void sys_tick_handler(void){
     ++Tms;
 }
 
-// usb getline
-char *get_USB(){
-    static char tmpbuf[USBBUFSZ+1], *curptr = tmpbuf;
-    static int rest = USBBUFSZ;
-    uint8_t x = USB_receive(curptr);
-    if(!x) return NULL;
-    curptr[x] = 0;
-    if(curptr[x-1] == '\n'){
-        curptr = tmpbuf;
-        rest = USBBUFSZ;
-        return tmpbuf;
-    }
-    curptr += x; rest -= x;
-    if(rest <= 0){ // buffer overflow
-        curptr = tmpbuf;
-        rest = USBBUFSZ;
-        USEND("USB buffer overflow\n");
-    }
-    return NULL;
-}
-
 int main(void){
+    char inbuff[MAXSTRLEN+1];
     StartHSE();
     hw_setup();
     SysTick_Config(72000);
+    USBPU_OFF();
     hw_setup();
     usart_setup();
     USB_setup();
+    USBPU_ON();
 
     uint32_t ctr = Tms;
     while(1){
@@ -66,12 +48,16 @@ int main(void){
             LED_blink(LED0);
             usart_transmit();
         }
+        if(usartovr()){
+            usart_send("USART buffer overfull\n");
+        }
         char *txt = NULL;
-        usb_proc();
-        if((txt = get_USB())){
+        int l = USB_receivestr(inbuff, MAXSTRLEN);
+        if(l < 0) USB_sendstr("ERROR: USB buffer overflow or string was too long\n");
+        else if(l){
             USEND("Got USB data\n");
-            const char *ans = parse_cmd(txt);
-            if(ans) USB_send(ans);
+            const char *ans = parse_cmd(inbuff);
+            if(ans) USB_sendstr(ans);
         }
         if(usartrx()){
             if(usart_getline(&txt)){
diff --git a/F1:F103/PL2303_ringbuffer/openocd.cfg b/F1:F103/PL2303_ringbuffer/openocd.cfg
new file mode 100644
index 0000000..18ecde1
--- /dev/null
+++ b/F1:F103/PL2303_ringbuffer/openocd.cfg
@@ -0,0 +1,4 @@
+set FLASH_SIZE 0x20000
+
+source [find interface/stlink-v2-1.cfg]
+source [find target/stm32f1x.cfg]
diff --git a/F1:F103/PL2303_ringbuffer/pl2303.cflags b/F1:F103/PL2303_ringbuffer/pl2303.cflags
new file mode 100644
index 0000000..68d5165
--- /dev/null
+++ b/F1:F103/PL2303_ringbuffer/pl2303.cflags
@@ -0,0 +1 @@
+-std=c17
\ No newline at end of file
diff --git a/F1:F103/PL2303_ringbuffer/pl2303.config b/F1:F103/PL2303_ringbuffer/pl2303.config
new file mode 100644
index 0000000..c41f0d7
--- /dev/null
+++ b/F1:F103/PL2303_ringbuffer/pl2303.config
@@ -0,0 +1,6 @@
+// Add predefined macros for your project here. For example:
+// #define THE_ANSWER 42
+#define EBUG
+#define STM32F1
+#define STM32F103x8
+#define STM32F10X_MD
diff --git a/F1:F103/PL2303_ringbuffer/pl2303.creator b/F1:F103/PL2303_ringbuffer/pl2303.creator
new file mode 100644
index 0000000..e94cbbd
--- /dev/null
+++ b/F1:F103/PL2303_ringbuffer/pl2303.creator
@@ -0,0 +1 @@
+[General]
diff --git a/F1:F103/PL2303_ringbuffer/pl2303.creator.user b/F1:F103/PL2303_ringbuffer/pl2303.creator.user
new file mode 100644
index 0000000..0e70a42
--- /dev/null
+++ b/F1:F103/PL2303_ringbuffer/pl2303.creator.user
@@ -0,0 +1,171 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE QtCreatorProject>
+<!-- Written by QtCreator 8.0.2, 2023-06-11T19:24:48. -->
+<qtcreator>
+ <data>
+  <variable>EnvironmentId</variable>
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+</qtcreator>
diff --git a/F1:F103/PL2303_ringbuffer/pl2303.cxxflags b/F1:F103/PL2303_ringbuffer/pl2303.cxxflags
new file mode 100644
index 0000000..6435dfc
--- /dev/null
+++ b/F1:F103/PL2303_ringbuffer/pl2303.cxxflags
@@ -0,0 +1 @@
+-std=c++17
\ No newline at end of file
diff --git a/F1:F103/PL2303_ringbuffer/pl2303.files b/F1:F103/PL2303_ringbuffer/pl2303.files
new file mode 100644
index 0000000..68d42e7
--- /dev/null
+++ b/F1:F103/PL2303_ringbuffer/pl2303.files
@@ -0,0 +1,15 @@
+hardware.c
+hardware.h
+main.c
+proto.c
+proto.h
+ringbuffer.c
+ringbuffer.h
+usart.c
+usart.h
+usb.c
+usb.h
+usb_lib.c
+usb_lib.h
+usbhw.c
+usbhw.h
diff --git a/F1:F103/PL2303_ringbuffer/pl2303.includes b/F1:F103/PL2303_ringbuffer/pl2303.includes
new file mode 100644
index 0000000..06d1130
--- /dev/null
+++ b/F1:F103/PL2303_ringbuffer/pl2303.includes
@@ -0,0 +1,6 @@
+.
+../inc
+../inc/Fx
+../inc/cm
+../inc/ld
+../inc/startup
diff --git a/F1:F103/PL2303_ringbuffer/proto.c b/F1:F103/PL2303_ringbuffer/proto.c
index 273335b..b56ac7a 100644
--- a/F1:F103/PL2303_ringbuffer/proto.c
+++ b/F1:F103/PL2303_ringbuffer/proto.c
@@ -194,12 +194,12 @@ const char *parse_cmd(const char *buf){
                 else add2buf("on\n");
             break;
             case 'R':
-                USB_send("Soft reset\n");
+                USB_sendstr("Soft reset\n");
                 NVIC_SystemReset();
             break;
             case 'T':
                 u3 = Tms;
-                for(int i = 0; i < 1000; ++i) USB_send(test);
+                for(int i = 0; i < 1000; ++i) USB_sendstr(test);
                 add2buf("\n\nspd=");
                 add2buf(u2str(2000000000/(Tms - u3))); add2buf("\n"); // strlen == 2Mbit, speed in bits per second
             break;
@@ -210,7 +210,7 @@ const char *parse_cmd(const char *buf){
                 add2buf("\n");
             break;
             case 'W':
-                USB_send("Wait for reboot\n");
+                USB_sendstr("Wait for reboot\n");
                 while(1){nop();};
             break;
             default:
diff --git a/F1:F103/PL2303_ringbuffer/ringbuffer.c b/F1:F103/PL2303_ringbuffer/ringbuffer.c
index f2b5f9f..0d10cd7 100644
--- a/F1:F103/PL2303_ringbuffer/ringbuffer.c
+++ b/F1:F103/PL2303_ringbuffer/ringbuffer.c
@@ -1,6 +1,6 @@
 /*
  * This file is part of the pl2303 project.
- * Copyright 2022 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ * Copyright 2023 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
@@ -16,64 +16,109 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include <stm32f1.h>
-
 #include "ringbuffer.h"
-#include "usb.h"
-#include "usb_lib.h"
 
-// ring buffer
-static char ringbuffer[RBSIZE];
-// head - position of first data byte
-// tail - position of last data byte + 1
-// head == tail - empty! So, buffer can't store more than RBSIZE-1 bytes of data!
-static volatile int head = 0, tail = 0;
-
-static int datalen(){
-    if(tail >= head) return (tail - head);
-    else return (RBSIZE - head + tail);
-}
-static int restlen(){
-    return (RBSIZE - 1 - datalen());
+// stored data length
+int RB_datalen(ringbuffer *b){
+    if(b->tail >= b->head) return (b->tail - b->head);
+    else return (b->length - b->head + b->tail);
 }
 
-static void mcpy(char *targ, const char *src, int l){
+/**
+ * @brief RB_hasbyte - check if buffer has given byte stored
+ * @param b - buffer
+ * @param byte - byte to find
+ * @return index if found, -1 if none
+ */
+int RB_hasbyte(ringbuffer *b, uint8_t byte){
+    if(b->head == b->tail) return -1; // no data in buffer
+    int startidx = b->head;
+    if(b->head > b->tail){ //
+        for(int found = b->head; found < b->length; ++found)
+            if(b->data[found] == byte) return found;
+        startidx = 0;
+    }
+    for(int found = startidx; found < b->tail; ++found)
+        if(b->data[found] == byte) return found;
+    return -1;
+}
+
+// poor memcpy
+static void mcpy(uint8_t *targ, const uint8_t *src, int l){
     while(l--) *targ++ = *src++;
 }
 
-TRUE_INLINE void incr(volatile int *what, int n){
+// increment head or tail
+TRUE_INLINE void incr(ringbuffer *b, volatile int *what, int n){
     *what += n;
-    if(*what >= RBSIZE) *what -= RBSIZE;
+    if(*what >= b->length) *what -= b->length;
 }
 
-int RB_read(char s[BLOCKSIZE]){
-    int l = datalen();
+/**
+ * @brief RB_read - read data from ringbuffer
+ * @param b - buffer
+ * @param s - array to write data
+ * @param len - max len of `s`
+ * @return bytes read
+ */
+int RB_read(ringbuffer *b, uint8_t *s, int len){
+    int l = RB_datalen(b);
     if(!l) return 0;
-    if(l > BLOCKSIZE) l = BLOCKSIZE;
-    int _1st = RBSIZE - head;
+    if(l > len) l = len;
+    int _1st = b->length - b->head;
     if(_1st > l) _1st = l;
-    if(_1st > BLOCKSIZE) _1st = BLOCKSIZE;
-    mcpy(s, ringbuffer+head, _1st);
-    if(_1st < BLOCKSIZE && l > _1st){
-        mcpy(s+_1st, ringbuffer, l-_1st);
-        incr(&head, l);
+    if(_1st > len) _1st = len;
+    mcpy(s, b->data + b->head, _1st);
+    if(_1st < len && l > _1st){
+        mcpy(s+_1st, b->data, l - _1st);
+        incr(b, &b->head, l);
         return l;
     }
-    incr(&head ,_1st);
+    incr(b, &b->head, _1st);
     return _1st;
 }
 
-int RB_write(const char *str, int l){
-    int r = restlen();
+/**
+ * @brief RB_readto fill array `s` with data until byte `byte` (with it)
+ * @param b - ringbuffer
+ * @param byte - check byte
+ * @param s - buffer to write data
+ * @param len - length of `s`
+ * @return amount of bytes written (negative, if len<data in buffer)
+ */
+int RB_readto(ringbuffer *b, uint8_t byte, uint8_t *s, int len){
+    int idx = RB_hasbyte(b, byte);
+    if(idx < 0) return 0;
+    int partlen = idx + 1 - b->head;
+    // now calculate length of new data portion
+    if(idx < b->head) partlen += b->length;
+    if(partlen > len) return -RB_read(b, s, len);
+    return RB_read(b, s, partlen);
+}
+
+/**
+ * @brief RB_write - write some data to ringbuffer
+ * @param b - buffer
+ * @param str - data
+ * @param l - length
+ * @return amount of bytes written
+ */
+int RB_write(ringbuffer *b, const uint8_t *str, int l){
+    int r = b->length - 1 - RB_datalen(b); // rest length
     if(l > r) l = r;
     if(!l) return 0;
-    int _1st = RBSIZE - tail;
+    int _1st = b->length - b->tail;
     if(_1st > l) _1st = l;
-    mcpy(ringbuffer+tail, str, _1st);
+    mcpy(b->data + b->tail, str, _1st);
     if(_1st < l){ // add another piece from start
-        mcpy(ringbuffer, str+_1st, l-_1st);
+        mcpy(b->data, str+_1st, l-_1st);
     }
-    incr(&tail, l);
+    incr(b, &b->tail, l);
     return l;
 }
 
+// just delete all information in buffer `b`
+void RB_clearbuf(ringbuffer *b){
+    b->head = 0;
+    b->tail = 0;
+}
diff --git a/F1:F103/PL2303_ringbuffer/ringbuffer.h b/F1:F103/PL2303_ringbuffer/ringbuffer.h
index 404fcbb..34daa76 100644
--- a/F1:F103/PL2303_ringbuffer/ringbuffer.h
+++ b/F1:F103/PL2303_ringbuffer/ringbuffer.h
@@ -1,6 +1,6 @@
 /*
  * This file is part of the pl2303 project.
- * Copyright 2022 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ * Copyright 2023 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
@@ -17,17 +17,19 @@
  */
 
 #pragma once
-#ifndef RINGBUFFER_H__
-#define RINGBUFFER_H__
+#include <stm32f1.h>
 
-#include "usbhw.h"
+typedef struct{
+    uint8_t *data;      // data buffer
+    const int length;   // its length
+    int head;           // head index
+    int tail;           // tail index
+} ringbuffer;
 
-// ring buffer size in bytes
-#define RBSIZE      (512)
-// max reading portion size
-#define BLOCKSIZE   (USB_TXBUFSZ)
+int RB_read(ringbuffer *b, uint8_t *s, int len);
+int RB_readto(ringbuffer *b, uint8_t byte, uint8_t *s, int len);
+int RB_hasbyte(ringbuffer *b, uint8_t byte);
+int RB_write(ringbuffer *b, const uint8_t *str, int l);
+int RB_datalen(ringbuffer *b);
+void RB_clearbuf(ringbuffer *b);
 
-int RB_read(char s[BLOCKSIZE]);
-int RB_write(const char *str, int l);
-
-#endif // RINGBUFFER_H__
diff --git a/F1:F103/PL2303_ringbuffer/usart.c b/F1:F103/PL2303_ringbuffer/usart.c
index 76c2e38..c3b8855 100644
--- a/F1:F103/PL2303_ringbuffer/usart.c
+++ b/F1:F103/PL2303_ringbuffer/usart.c
@@ -91,7 +91,7 @@ void usart_setup(){
     // PA9 - Tx, PA10 - Rx 
     RCC->APB2ENR |= RCC_APB2ENR_IOPAEN | RCC_APB2ENR_USART1EN | RCC_APB2ENR_AFIOEN;
     RCC->AHBENR |= RCC_AHBENR_DMA1EN;
-    GPIOA->CRH = CRH(9, CNF_AFPP|MODE_NORMAL) | CRH(10, CNF_FLINPUT|MODE_INPUT); 
+    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
diff --git a/F1:F103/PL2303_ringbuffer/usb.c b/F1:F103/PL2303_ringbuffer/usb.c
index f39a217..553b6cf 100644
--- a/F1:F103/PL2303_ringbuffer/usb.c
+++ b/F1:F103/PL2303_ringbuffer/usb.c
@@ -1,6 +1,6 @@
 /*
- * This file is part of the MLX90640 project.
- * Copyright 2022 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ * This file is part of the pl2303 project.
+ * Copyright 2023 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
@@ -16,101 +16,111 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#include "ringbuffer.h"
+#include <string.h>
+
+#include "hardware.h"
 #include "usb.h"
 #include "usb_lib.h"
 
-static char usbbuff[USB_TXBUFSZ]; // temporary buffer for sending data
-volatile uint8_t tx_succesfull = 1;
-static volatile uint8_t rxNE = 0;
+static volatile uint8_t usbbuff[USB_TXBUFSZ]; // temporary buffer for sending data
+// ring buffers for incoming and outgoing data
+static uint8_t obuf[RBOUTSZ], ibuf[RBINSZ];
+volatile ringbuffer rbout = {.data = obuf, .length = RBOUTSZ, .head = 0, .tail = 0};
+volatile ringbuffer rbin = {.data = ibuf, .length = RBINSZ, .head = 0, .tail = 0};
+// transmission is succesfull
+volatile uint8_t bufisempty = 1;
+volatile uint8_t bufovrfl = 0;
 
 void send_next(){
-    //if(!tx_succesfull) return;
+    if(bufisempty) return;
     static int lastdsz = 0;
-    int buflen = RB_read(usbbuff);
+    int buflen = RB_read((ringbuffer*)&rbout, (uint8_t*)usbbuff, USB_TXBUFSZ);
     if(!buflen){
         if(lastdsz == 64) EP_Write(3, NULL, 0); // send ZLP after 64 bits packet when nothing more to send
         lastdsz = 0;
+        bufisempty = 1;
         return;
     }
-    tx_succesfull = 0;
     EP_Write(3, (uint8_t*)usbbuff, buflen);
     lastdsz = buflen;
 }
 
+// blocking send full content of ring buffer
+int USB_sendall(){
+    while(!bufisempty){
+        if(!usbON) return 0;
+    }
+    return 1;
+}
+
 // put `buf` into queue to send
-void USB_send(const char *buf){
-    if(!buf || !usbON) return;
-    int len = 0;
-    const char *b = buf;
-    while(*b++) ++len;
-    if(!usbON || !len) return;
-    int l = len;
-    while(l){
-        if(tx_succesfull) send_next();
-        int a = RB_write(buf, l);
-        l -= a;
+int USB_send(const uint8_t *buf, int len){
+    if(!buf || !usbON || !len) return 0;
+    while(len){
+        int a = RB_write((ringbuffer*)&rbout, buf, len);
+        len -= a;
         buf += a;
+        if(bufisempty){
+            bufisempty = 0;
+            send_next();
+        }
     }
+    return 1;
 }
 
-// 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_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;
-            if(tx_succesfull) send_next();
+int USB_putbyte(uint8_t byte){
+    if(!usbON) return 0;
+    while(0 == RB_write((ringbuffer*)&rbout, &byte, 1)){
+        if(bufisempty){
+            bufisempty = 0;
+            send_next();
+        }
     }
+    return 1;
+}
+
+int USB_sendstr(const char *string){
+    if(!string || !usbON) return 0;
+    int len = 0;
+    const char *b = string;
+    while(*b++) ++len;
+    if(!len) return 0;
+    return USB_send((const uint8_t*)string, len);
 }
 
 /**
- * @brief USB_receive
- * @param buf (i) - buffer[64] for received data
- * @return amount of received bytes
+ * @brief USB_receive - get binary data from receiving ring-buffer
+ * @param buf (i) - buffer for received data
+ * @param len - length of `buf`
+ * @return amount of received bytes (negative, if overfull happened)
  */
-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;
+int USB_receive(uint8_t *buf, int len){
+    int sz = RB_read((ringbuffer*)&rbin, buf, len);
+    if(bufovrfl){
+        RB_clearbuf((ringbuffer*)&rbin);
+        if(!sz) sz = -1;
+        else sz = -sz;
+        bufovrfl = 0;
+    }
     return sz;
 }
+
+/**
+ * @brief USB_receivestr - get string up to '\n' and replace '\n' with 0
+ * @param buf - receiving buffer
+ * @param len - its length
+ * @return strlen or negative value indicating overflow (if so, string won't be ends with 0 and buffer should be cleared)
+ */
+int USB_receivestr(char *buf, int len){
+    int l = RB_readto((ringbuffer*)&rbin, '\n', (uint8_t*)buf, len);
+    if(l == 0) return 0;
+    if(--l < 0 || bufovrfl) RB_clearbuf((ringbuffer*)&rbin);
+    else buf[l] = 0; // replace '\n' with strend
+    if(bufovrfl){
+        if(l > 0) l = -l;
+        else l = -1;
+        bufovrfl = 0;
+    }
+    return l;
+}
+
diff --git a/F1:F103/PL2303_ringbuffer/usb.h b/F1:F103/PL2303_ringbuffer/usb.h
index 6e62b64..2a58624 100644
--- a/F1:F103/PL2303_ringbuffer/usb.h
+++ b/F1:F103/PL2303_ringbuffer/usb.h
@@ -1,6 +1,6 @@
 /*
- * This file is part of the MLX90640 project.
- * Copyright 2022 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ * This file is part of the pl2303 project.
+ * Copyright 2023 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
@@ -17,18 +17,33 @@
  */
 
 #pragma once
-#ifndef __USB_H__
-#define __USB_H__
-
+#include "ringbuffer.h"
 #include "usbhw.h"
 
-#define BUFFSIZE   (64)
+// sizes of ringbuffers for outgoing and incoming data
+#define RBOUTSZ     (512)
+#define RBINSZ      (512)
 
-extern volatile uint8_t tx_succesfull;
+#define newline()   USB_putbyte('\n')
+#define USND(s)     do{USB_sendstr(s); USB_putbyte('\n');}while(0)
+
+#if 0
+#define STR_HELPER(s)   #s
+#define STR(s)          STR_HELPER(s)
+#ifdef EBUG
+#define DBG(str)  do{USB_sendstr(__FILE__ " (L" STR(__LINE__) "): " str); newline();}while(0)
+#else
+#define DBG(str)
+#endif
+#endif
+
+extern volatile ringbuffer rbout, rbin;
+extern volatile uint8_t bufisempty, bufovrfl;
 
-void usb_proc();
 void send_next();
-void USB_send(const char *buf);
-uint8_t USB_receive(char *buf);
-
-#endif // __USB_H__
+int USB_sendall();
+int USB_send(const uint8_t *buf, int len);
+int USB_putbyte(uint8_t byte);
+int USB_sendstr(const char *string);
+int USB_receive(uint8_t *buf, int len);
+int USB_receivestr(char *buf, int len);
diff --git a/F1:F103/PL2303_ringbuffer/usb_lib.c b/F1:F103/PL2303_ringbuffer/usb_lib.c
index e9c4ba5..49eb681 100644
--- a/F1:F103/PL2303_ringbuffer/usb_lib.c
+++ b/F1:F103/PL2303_ringbuffer/usb_lib.c
@@ -1,6 +1,6 @@
 /*
- * This file is part of the MLX90640 project.
- * Copyright 2022 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ * This file is part of the pl2303 project.
+ * Copyright 2023 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
@@ -17,19 +17,20 @@
  */
 
 #include <stdint.h>
+#include "usb.h"
 #include "usb_lib.h"
+#include "usbhw.h"
 
 ep_t endpoints[STM32ENDPOINTS];
 
-usb_dev_t USB_Dev;
+static uint16_t USB_Addr = 0;
 static usb_LineCoding lineCoding = {115200, 0, 0, 8};
-config_pack_t setup_packet;
-uint8_t ep0databuf[EP0DATABUF_SIZE];
-uint8_t ep0dbuflen = 0;
+uint8_t ep0databuf[EP0DATABUF_SIZE], setupdatabuf[EP0DATABUF_SIZE];
+static config_pack_t *setup_packet = (config_pack_t*) setupdatabuf;
 
 usb_LineCoding getLineCoding(){return lineCoding;}
 
-uint8_t usbON = 0; // device disconnected from terminal
+volatile uint8_t usbON = 0; // device disconnected from terminal
 
 // definition of parts common for USB_DeviceDescriptor & USB_DeviceQualifierDescriptor
 #define bcdUSB_L        0x10
@@ -54,9 +55,9 @@ static const uint8_t USB_DeviceDescriptor[] = {
         0x23,   // idProduct_H
         0x00,   // bcdDevice_Ver_L
         0x03,   // bcdDevice_Ver_H
-        0x01,   // iManufacturer
-        0x02,   // iProduct
-        0x00,   // iSerialNumber
+        iMANUFACTURER_DESCR,   // iManufacturer
+        iPRODUCT_DESCR,   // iProduct
+        iSERIAL_DESCR,   // iSerialNumber
         bNumConfigurations    // bNumConfigurations
 };
 
@@ -96,7 +97,7 @@ static const uint8_t USB_ConfigDescriptor[] = {
         0xff, /* bInterfaceClass */
         0x00, /* bInterfaceSubClass */
         0x00, /* bInterfaceProtocol */
-        0x00, /* iInterface: */
+        iINTERFACE_DESCR, /* iInterface: */
 ///////////////////////////////////////////////////
         /*Endpoint 1 Descriptor*/
         0x07, /* bLength: Endpoint Descriptor size */
@@ -126,11 +127,19 @@ static const uint8_t USB_ConfigDescriptor[] = {
         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");
+_USB_LANG_ID_(LD, LANG_US);
+_USB_STRING_(SD, u"0.0.1");
+_USB_STRING_(MD, u"Prolific Technology Inc.");
+_USB_STRING_(PD, u"USB-Serial Controller");
+_USB_STRING_(ID, u"pl2303_emulator");
+static void const *StringDescriptor[iDESCR_AMOUNT] = {
+    [iLANGUAGE_DESCR] = &LD,
+    [iMANUFACTURER_DESCR] = &MD,
+    [iPRODUCT_DESCR] = &PD,
+    [iSERIAL_DESCR] = &SD,
+    [iINTERFACE_DESCR] = &ID
+};
+
 
 /*
  * default handlers
@@ -149,8 +158,8 @@ void WEAK break_handler(){
 
 // handler of vendor requests
 void WEAK vendor_handler(config_pack_t *packet){
+    uint16_t c;
     if(packet->bmRequestType & 0x80){ // read
-        uint8_t c;
         switch(packet->wValue){
             case 0x8484:
                 c = 2;
@@ -164,14 +173,15 @@ void WEAK vendor_handler(config_pack_t *packet){
             default:
                 c = 0;
         }
-        EP_WriteIRQ(0, &c, 1);
+        EP_WriteIRQ(0, (uint8_t*)&c, 1);
     }else{ // write ZLP
-        EP_WriteIRQ(0, (uint8_t *)0, 0);
+        c = 0;
+        EP_WriteIRQ(0, (uint8_t *)&c, 0);
     }
 }
 
 static void wr0(const uint8_t *buf, uint16_t size){
-    if(setup_packet.wLength < size) size = setup_packet.wLength; // shortened request
+    if(setup_packet->wLength < size) size = setup_packet->wLength; // shortened request
     if(size < endpoints[0].txbufsz){
         EP_WriteIRQ(0, buf, size);
         return;
@@ -199,24 +209,18 @@ static void wr0(const uint8_t *buf, uint16_t size){
 }
 
 static inline void get_descriptor(){
-    switch(setup_packet.wValue){
+    uint8_t descrtype = setup_packet->wValue >> 8,
+            descridx = setup_packet->wValue & 0xff;
+    switch(descrtype){
         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);
+        case STRING_DESCRIPTOR:
+            if(descridx < iDESCR_AMOUNT) wr0((const uint8_t *)StringDescriptor[descridx], *((uint8_t*)StringDescriptor[descridx]));
+            else EP_WriteIRQ(0, (uint8_t*)0, 0);
         break;
         case DEVICE_QUALIFIER_DESCRIPTOR:
             wr0(USB_DeviceQualifierDescriptor, USB_DeviceQualifierDescriptor[0]);
@@ -226,10 +230,10 @@ static inline void get_descriptor(){
     }
 }
 
-static uint8_t configuration = 0; // reply for GET_CONFIGURATION (==1 if configured)
+static uint16_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){
+    switch(setup_packet->bRequest){
         case GET_DESCRIPTOR:
             get_descriptor();
         break;
@@ -237,23 +241,54 @@ static inline void std_d2h_req(){
             EP_WriteIRQ(0, (uint8_t *)&status, 2); // send status: Bus Powered
         break;
         case GET_CONFIGURATION:
-            EP_WriteIRQ(0, &configuration, 1);
+            EP_WriteIRQ(0, (uint8_t*)&configuration, 1);
         break;
         default:
         break;
     }
 }
 
+// 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
+    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
+    send_next();
+}
+
+static void receive_Handler(){ // EP2OUT
+    uint8_t buf[USB_RXBUFSZ];
+    uint16_t epstatus = KEEP_DTOG(USB->EPnR[2]);
+    uint8_t sz = EP_Read(2, (uint8_t*)buf);
+    if(sz){
+        if(RB_write((ringbuffer*)&rbin, buf, sz) != sz) bufovrfl = 1;
+    }
+    // keep stat_tx & set ACK rx, clear RX ctr
+    USB->EPnR[2] = (epstatus & ~USB_EPnR_CTR_RX) ^ USB_EPnR_STAT_RX;
+}
+
 static inline void std_h2d_req(){
-    switch(setup_packet.bRequest){
+    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;
+            USB_Addr = setup_packet->wValue;
         break;
         case SET_CONFIGURATION:
             // Now device configured
-            USB_Dev.USB_Status = USB_STATE_CONFIGURED;
-            configuration = setup_packet.wValue;
+            configuration = setup_packet->wValue;
+            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
         break;
         default:
         break;
@@ -271,8 +306,8 @@ bmRequestType: 76543210
  */
 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;
+    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){
@@ -285,15 +320,15 @@ void EP0_Handler(){
                 }
             break;
             case STANDARD_ENDPOINT_REQUEST_TYPE: // standard endpoint request
-                if(setup_packet.bRequest == CLEAR_FEATURE){
+                if(setup_packet->bRequest == CLEAR_FEATURE){
                     EP_WriteIRQ(0, (uint8_t *)0, 0);
                 }
             break;
             case VENDOR_REQUEST_TYPE:
-                vendor_handler(&setup_packet);
+                vendor_handler(setup_packet);
             break;
             case CONTROL_REQUEST_TYPE:
-                switch(setup_packet.bRequest){
+                switch(setup_packet->bRequest){
                     case GET_LINE_CODING:
                         EP_WriteIRQ(0, (uint8_t*)&lineCoding, sizeof(lineCoding));
                     break;
@@ -301,7 +336,7 @@ void EP0_Handler(){
                     break;
                     case SET_CONTROL_LINE_STATE:
                         usbON = 1;
-                        clstate_handler(setup_packet.wValue);
+                        clstate_handler(setup_packet->wValue);
                     break;
                     case SEND_BREAK:
                         usbON = 0;
@@ -310,23 +345,22 @@ void EP0_Handler(){
                     default:
                     break;
                 }
-                if(setup_packet.bRequest != GET_LINE_CODING) EP_WriteIRQ(0, (uint8_t *)0, 0); // write acknowledgement
+                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){
+            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;
+        if ((USB->DADDR & USB_DADDR_ADD) != USB_Addr){
+            USB->DADDR = USB_DADDR_EF | USB_Addr;
+            usbON = 0;
         }
     }
     epstatus = KEEP_DTOG(USB->EPnR[0]);
@@ -343,16 +377,24 @@ void EP0_Handler(){
  * @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;
     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;
+#if defined USB1_16
+    // very bad: what if `size` is odd?
     uint32_t *out = (uint32_t *)endpoints[number].tx_buf;
-    for(i = 0; i < N2; ++i, ++out){
+    for(int i = 0; i < N2; ++i, ++out){
         *out = buf16[i];
     }
+#elif defined USB2_16
+    // use memcpy instead?
+    for(int i = 0; i < N2; i++){
+        endpoints[number].tx_buf[i] = buf16[i];
+    }
+#else
+#error "Define USB1_16 or USB2_16"
+#endif
     USB_BTABLE->EP[number].USB_COUNT_TX = size;
 }
 
@@ -374,16 +416,23 @@ void EP_Write(uint8_t number, const uint8_t *buf, uint16_t size){
  * @param *buf - user array for data
  * @return amount of data read
  */
-int EP_Read(uint8_t number, uint16_t *buf){
+int EP_Read(uint8_t number, uint8_t *buf){
     int sz = endpoints[number].rx_cnt;
     if(!sz) return 0;
     endpoints[number].rx_cnt = 0;
+#if defined USB1_16
     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;
-    }
+    uint32_t *in = (uint32_t*)endpoints[number].rx_buf;
+    uint16_t *out = (uint16_t*)buf;
+    for(int i = 0; i < n; ++i, ++in)
+        out[i] = *(uint16_t*)in;
+#elif defined USB2_16
+    // use memcpy instead?
+    for(int i = 0; i < sz; ++i)
+        buf[i] = endpoints[number].rx_buf[i];
+#else
+#error "Define USB1_16 or USB2_16"
+#endif
     return sz;
 }
 
diff --git a/F1:F103/PL2303_ringbuffer/usb_lib.h b/F1:F103/PL2303_ringbuffer/usb_lib.h
index 739fe2d..d509e4f 100644
--- a/F1:F103/PL2303_ringbuffer/usb_lib.h
+++ b/F1:F103/PL2303_ringbuffer/usb_lib.h
@@ -1,6 +1,6 @@
 /*
- * This file is part of the MLX90640 project.
- * Copyright 2022 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ * This file is part of the pl2303 project.
+ * Copyright 2023 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
@@ -17,9 +17,6 @@
  */
 
 #pragma once
-#ifndef __USB_LIB_H__
-#define __USB_LIB_H__
-
 #include <wchar.h>
 #include "usbhw.h"
 
@@ -62,14 +59,21 @@
 #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
+// string descriptors
+enum{
+    iLANGUAGE_DESCR,
+    iMANUFACTURER_DESCR,
+    iPRODUCT_DESCR,
+    iSERIAL_DESCR,
+    iINTERFACE_DESCR,
+    iDESCR_AMOUNT
+};
+
+// Types of descriptors
+#define DEVICE_DESCRIPTOR               0x01
+#define CONFIGURATION_DESCRIPTOR        0x02
+#define STRING_DESCRIPTOR               0x03
+#define DEVICE_QUALIFIER_DESCRIPTOR     0x06
 
 #define RX_FLAG(epstat)                 (epstat & USB_EPnR_CTR_RX)
 #define TX_FLAG(epstat)                 (epstat & USB_EPnR_CTR_TX)
@@ -79,14 +83,6 @@
 #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
@@ -115,7 +111,6 @@ static const struct name \
     \
 } \
 name = {0x04, 0x03, lng_id}
-#define STRING_LANG_DESCRIPTOR_SIZE_BYTE    (4)
 
 // EP0 configuration packet
 typedef struct {
@@ -130,17 +125,11 @@ typedef struct {
 typedef struct{
     uint16_t *tx_buf;           // transmission buffer address
     uint16_t txbufsz;           // transmission buffer size
-    uint16_t *rx_buf;           // reception buffer address
+    uint8_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;
@@ -165,22 +154,17 @@ typedef struct {
 } __attribute__ ((packed)) usb_cdc_notification;
 
 extern ep_t endpoints[];
-extern usb_dev_t USB_Dev;
-extern uint8_t usbON;
-extern config_pack_t setup_packet;
-extern uint8_t ep0databuf[];
-extern uint8_t ep0dbuflen;
+extern volatile uint8_t usbON;
+extern uint8_t ep0databuf[], setupdatabuf[];
 
 void EP0_Handler();
 
 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);
+int EP_Read(uint8_t number, uint8_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__
diff --git a/F1:F103/PL2303_ringbuffer/usbhw.c b/F1:F103/PL2303_ringbuffer/usbhw.c
index d93c927..ac73fcf 100644
--- a/F1:F103/PL2303_ringbuffer/usbhw.c
+++ b/F1:F103/PL2303_ringbuffer/usbhw.c
@@ -26,8 +26,6 @@ void USB_setup(){
     USBPU_OFF();
     RCC->APB1ENR |= RCC_APB1ENR_USBEN;
     RCC->APB2ENR |= USB_RCC;
-    // USB pullup (PA15) - pushpull output
-    GPIOA->CRH |= CRH(15, CNF_PPOUTPUT | MODE_SLOW);
     USB->CNTR   = USB_CNTR_FRES; // Force USB Reset
     for(uint32_t ctr = 0; ctr < 72000; ++ctr) nop(); // wait >1ms
     //uint32_t ctr = 0;
@@ -64,12 +62,12 @@ int EP_Init(uint8_t number, uint8_t type, uint16_t txsz, uint16_t rxsz, void (*f
         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].tx_buf = (uint16_t *)(USB_BTABLE_BASE + lastaddr * ACCESSZ);
     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);
+    endpoints[number].rx_buf = (uint8_t *)(USB_BTABLE_BASE + lastaddr * ACCESSZ);
     lastaddr += rxsz;
     USB_BTABLE->EP[number].USB_COUNT_RX = countrx << 10;
     endpoints[number].func = func;
@@ -82,17 +80,15 @@ void usb_lp_can_rx0_isr(){
         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;
         }
+        USB->ISTR = ~USB_ISTR_RESET;
     }
     if(USB->ISTR & USB_ISTR_CTR){
         // EP number
@@ -105,12 +101,10 @@ void usb_lp_can_rx0_isr(){
         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;
+                    EP_Read(0, setupdatabuf);
                     // 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);
+                    EP_Read(0, ep0databuf);
                 }
             }
         }
@@ -127,4 +121,3 @@ void usb_lp_can_rx0_isr(){
         USB->ISTR = ~USB_ISTR_WKUP;
     }
 }
-
diff --git a/F1:F103/PL2303_ringbuffer/usbhw.h b/F1:F103/PL2303_ringbuffer/usbhw.h
index ac41455..fadac61 100644
--- a/F1:F103/PL2303_ringbuffer/usbhw.h
+++ b/F1:F103/PL2303_ringbuffer/usbhw.h
@@ -17,16 +17,13 @@
  */
 
 #pragma once
-#ifndef USBHW_H__
-#define USBHW_H__
-
 #include <stm32f1.h>
 
 #define USB_RCC     RCC_APB2ENR_IOPAEN
 #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 USBPU_ON()  pin_clear(USBPU_port, USBPU_pin)
+#define USBPU_OFF() pin_set(USBPU_port, USBPU_pin)
 
 // max endpoints number
 #define STM32ENDPOINTS          8
@@ -34,8 +31,6 @@
  *                 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)
@@ -93,10 +88,23 @@ typedef struct {
 } USB_TypeDef;
 
 typedef struct{
+#if defined USB2_16
+    __IO uint16_t USB_ADDR_TX;
+    __IO uint16_t USB_COUNT_TX;
+    __IO uint16_t USB_ADDR_RX;
+    __IO uint16_t USB_COUNT_RX;
+#define ACCESSZ (1)
+#define BUFTYPE uint8_t
+#elif defined USB1_16
     __IO uint32_t USB_ADDR_TX;
     __IO uint32_t USB_COUNT_TX;
     __IO uint32_t USB_ADDR_RX;
     __IO uint32_t USB_COUNT_RX;
+#define ACCESSZ (2)
+#define BUFTYPE uint16_t
+#else
+#error "Define USB1_16 or USB2_16"
+#endif
 } USB_EPDATA_TypeDef;
 
 typedef struct{
@@ -105,5 +113,3 @@ typedef struct{
 
 void USB_setup();
 int EP_Init(uint8_t number, uint8_t type, uint16_t txsz, uint16_t rxsz, void (*func)());
-
-#endif // USBHW_H__
diff --git a/F1:F103/PL2303_ringbuffer/version.inc b/F1:F103/PL2303_ringbuffer/version.inc
index 6ca1649..1f9f21d 100644
--- a/F1:F103/PL2303_ringbuffer/version.inc
+++ b/F1:F103/PL2303_ringbuffer/version.inc
@@ -1,2 +1,2 @@
-#define BUILD_NUMBER "72"
-#define BUILD_DATE "2023-01-11"
+#define BUILD_NUMBER "80"
+#define BUILD_DATE "2023-06-11"
diff --git a/testboard/F0_F1_F3-LQFP48_testboard/stm32.kicad_prl b/testboard/F0_F1_F3-LQFP48_testboard/stm32.kicad_prl
index eb0e5ac..a6fa347 100644
--- a/testboard/F0_F1_F3-LQFP48_testboard/stm32.kicad_prl
+++ b/testboard/F0_F1_F3-LQFP48_testboard/stm32.kicad_prl
@@ -3,10 +3,12 @@
     "active_layer": 0,
     "active_layer_preset": "All Copper Layers",
     "auto_track_width": true,
+    "hidden_netclasses": [],
     "hidden_nets": [],
     "high_contrast_mode": 0,
     "net_color_mode": 1,
     "opacity": {
+      "images": 0.6,
       "pads": 1.0,
       "tracks": 1.0,
       "vias": 1.0,
@@ -62,7 +64,7 @@
       35,
       36
     ],
-    "visible_layers": "fffffff_ffffffff",
+    "visible_layers": "0001000_ffffffff",
     "zone_display_mode": 1
   },
   "meta": {
diff --git a/testboard/F0_F1_F3-LQFP48_testboard/stm32.kicad_pro b/testboard/F0_F1_F3-LQFP48_testboard/stm32.kicad_pro
index cb6eea1..887ef34 100644
--- a/testboard/F0_F1_F3-LQFP48_testboard/stm32.kicad_pro
+++ b/testboard/F0_F1_F3-LQFP48_testboard/stm32.kicad_pro
@@ -1,5 +1,6 @@
 {
   "board": {
+    "3dviewports": [],
     "design_settings": {
       "defaults": {
         "board_outline_line_width": 0.09999999999999999,
@@ -137,7 +138,8 @@
       "zones_allow_external_fillets": false,
       "zones_use_no_outline": true
     },
-    "layer_presets": []
+    "layer_presets": [],
+    "viewports": []
   },
   "boards": [],
   "cvpcb": {
@@ -359,7 +361,7 @@
   "net_settings": {
     "classes": [
       {
-        "bus_width": 12.0,
+        "bus_width": 12,
         "clearance": 0.2,
         "diff_pair_gap": 0.25,
         "diff_pair_via_gap": 0.25,
@@ -373,13 +375,15 @@
         "track_width": 0.25,
         "via_diameter": 2.0,
         "via_drill": 0.6,
-        "wire_width": 6.0
+        "wire_width": 6
       }
     ],
     "meta": {
-      "version": 2
+      "version": 3
     },
-    "net_colors": null
+    "net_colors": null,
+    "netclass_assignments": null,
+    "netclass_patterns": []
   },
   "pcbnew": {
     "last_paths": {