diff --git a/F303-nolib/Readme.md b/F303-nolib/Readme.md
index 7128e4d..4d6b0f6 100644
--- a/F303-nolib/Readme.md
+++ b/F303-nolib/Readme.md
@@ -3,6 +3,8 @@ Samples for STM32F303
 
 Most of these samples works with [my non-solder devboard](https://github.com/eddyem/stm32samples/tree/master/F0_F1_F3-LQFP48_testboard)
 
-- blink - simple LEDs blink on PB0 and PB1
-- usart1 - read data from USART1 and send it back (blocking sending)
-- usarts - work with all three USARTs, send to USART1 data read from other, you can send "2\n" or "3\n" to USART1 for tests of USART2/USART3
+- **blink** - simple LEDs blink on PB0 and PB1
+- **usart1** - read data from USART1 and send it back (blocking sending)
+- **usarts** - work with all three USARTs with Tx DMA, send to USART1 data read from other, you can send "2\n" or "3\n" to USART1 for tests of USART2/USART3
+- **floatPrintf** - work with floats, convert floating point number into a string
+- **usart1fullDMA** - USART1 Rx and Tx DMA access (Rx terminated by character match of '\n' or buffer overflow).
diff --git a/F303-nolib/usart1fullDMA/Makefile b/F303-nolib/usart1fullDMA/Makefile
new file mode 100644
index 0000000..7ddce2f
--- /dev/null
+++ b/F303-nolib/usart1fullDMA/Makefile
@@ -0,0 +1,146 @@
+BINARY		= usart
+BOOTPORT	?= /dev/ttyUSB0
+BOOTSPEED	?= 115200
+# MCU FAMILY
+FAMILY		?= F3
+# MCU code
+MCU			?= F303xb
+# or __ARM_ARCH_7EM__
+ARMARCH = __ARM_ARCH_7M__
+# change this linking script depending on particular MCU model,
+LDSCRIPT	?= stm32f303xB.ld
+# debug
+#DEFS		= -DEBUG
+
+INDEPENDENT_HEADERS=
+
+FP_FLAGS	?= -mfpu=fpv4-sp-d16 -mfloat-abi=hard -fsingle-precision-constant
+ASM_FLAGS	?= -mthumb -mcpu=cortex-m4
+ARCH_FLAGS	= $(ASM_FLAGS) $(FP_FLAGS) -D $(ARMARCH)
+
+###############################################################################
+# 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
+MAP			:= $(OBJDIR)/$(BINARY).map
+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		+= -g -gdwarf-2
+CFLAGS		+= -O2 -D__thumb2__=1 -MD
+CFLAGS		+= -Wall -Werror -Wextra -Wshadow 
+CFLAGS		+= -fshort-enums -ffunction-sections -fdata-sections
+#CFLAGS		+= -fno-common -ffunction-sections -fdata-sections -fno-stack-protector
+CFLAGS		+=  $(ARCH_FLAGS)
+
+###############################################################################
+# Linker flags
+#LDFLAGS		+= -nostartfiles --static -nostdlib  -specs=nosys.specs -specs=nano.specs
+LDFLAGS		+= $(ARCH_FLAGS)
+LDFLAGS		+= -specs=nosys.specs -specs=nano.specs
+LDFLAGS		+= -L$(LIB_DIR)
+#LDFLAGS		+= -L$(TOOLCHLIB)
+LDFLAGS		+= -T$(LDSCRIPT)
+LDFLAGS		+= -Wl,-Map=$(MAP),--cref -Wl,--gc-sections
+
+###############################################################################
+# Used libraries
+#LDLIBS		+=  -lc $(shell $(CC) $(CFLAGS) -print-libgcc-file-name)
+
+DEFS		+= -DSTM32$(FAMILY) -DSTM32$(MCU)
+
+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)"
+	$(CC) $(LDFLAGS) $(OBJS) $(LDLIBS) -o $(ELF)
+
+size: $(ELF)
+	$(SIZE) $(ELF)    
+
+clean:
+	@echo "  CLEAN"
+	$(RM) $(OBJS) $(DEPS) $(ELF) $(HEX) $(LIST) $(MAP)
+	@rmdir $(OBJDIR) 2>/dev/null || true
+
+
+flash: $(BIN)
+	@echo "  FLASH  $(BIN)"
+	$(STFLASH) write $(BIN) 0x8000000
+
+boot: $(BIN)
+	@echo "  LOAD $(BIN) through bootloader"
+	$(STBOOT) -b$(BOOTSPEED) $(BOOTPORT) -w $(BIN)
+
+dfuboot: $(BIN)
+	@echo "  LOAD  $(BIN) THROUGH DFU"
+	$(DFUUTIL) -a0 -D $(BIN) -s 0x08000000
+
+.PHONY: clean flash boot
diff --git a/F303-nolib/usart1fullDMA/Readme b/F303-nolib/usart1fullDMA/Readme
new file mode 100644
index 0000000..42fa4bf
--- /dev/null
+++ b/F303-nolib/usart1fullDMA/Readme
@@ -0,0 +1 @@
+Full Rx and Tx DMA, Rx DMA ends on buffer end or when '\n' received by character match interrupt.
\ No newline at end of file
diff --git a/F303-nolib/usart1fullDMA/hardware.c b/F303-nolib/usart1fullDMA/hardware.c
new file mode 100644
index 0000000..c908fb9
--- /dev/null
+++ b/F303-nolib/usart1fullDMA/hardware.c
@@ -0,0 +1,32 @@
+/*
+ * This file is part of the F303usartDMA project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "hardware.h"
+#include "usart.h"
+
+static inline void gpio_setup(){
+    RCC->AHBENR |= RCC_AHBENR_GPIOAEN | RCC_AHBENR_GPIOBEN; // for USART and LEDs
+    for(int i = 0; i < 10; ++i) nop(); // don't know why, but next line won't work without a little delay
+    GPIOB->MODER = GPIO_MODER_MODER0_O | GPIO_MODER_MODER1_O;
+    GPIOB->ODR = 1;
+}
+
+void hw_setup(){
+    gpio_setup();
+}
+
diff --git a/F303-nolib/usart1fullDMA/hardware.h b/F303-nolib/usart1fullDMA/hardware.h
new file mode 100644
index 0000000..5e28a1b
--- /dev/null
+++ b/F303-nolib/usart1fullDMA/hardware.h
@@ -0,0 +1,27 @@
+/*
+ * This file is part of the F303usartDMA project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#ifndef __HARDWARE_H__
+#define __HARDWARE_H__
+
+#include "stm32f3.h"
+
+void hw_setup();
+
+#endif // __HARDWARE_H__
diff --git a/F303-nolib/usart1fullDMA/main.c b/F303-nolib/usart1fullDMA/main.c
new file mode 100644
index 0000000..da42b2f
--- /dev/null
+++ b/F303-nolib/usart1fullDMA/main.c
@@ -0,0 +1,54 @@
+/*
+ * This file is part of the F303usartDMA project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "stm32f3.h"
+#include "hardware.h"
+#include "usart.h"
+
+
+volatile uint32_t Tms = 0;
+
+void sys_tick_handler(void){
+    ++Tms;
+}
+
+int main(void){
+    //sysreset();
+    if(!StartHSE()) StartHSI();
+    SysTick_Config((uint32_t)72000); // 1ms
+    hw_setup();
+    usart_setup();
+    uint32_t ctr = Tms;
+    while(1){
+        if(Tms - ctr > 499){
+            ctr = Tms;
+            pin_toggle(GPIOB, 1 << 1 | 1 << 0); // toggle LED @ PB0
+        }
+        if(usart_ovr()) usart_send("Buffer overflow occured!\n");
+        if(chk_usart()){ // usart1 received data, store in in buffer
+            char *txt = NULL;
+            int r = usart_getline(&txt);
+            if(r){
+                txt[r] = 0;
+                usart_send("Got data: _");
+                usart_send(txt);
+                usart_send("_\n");
+            }
+        }
+    }
+}
diff --git a/F303-nolib/usart1fullDMA/usart.bin b/F303-nolib/usart1fullDMA/usart.bin
new file mode 100755
index 0000000..b2e741c
Binary files /dev/null and b/F303-nolib/usart1fullDMA/usart.bin differ
diff --git a/F303-nolib/usart1fullDMA/usart.c b/F303-nolib/usart1fullDMA/usart.c
new file mode 100644
index 0000000..93ca185
--- /dev/null
+++ b/F303-nolib/usart1fullDMA/usart.c
@@ -0,0 +1,184 @@
+/*
+ * This file is part of the F303usartDMA project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "stm32f3.h"
+#include "hardware.h"
+#include "usart.h"
+#include <string.h>
+
+extern volatile uint32_t Tms;
+static uint32_t lastAccessT = 0; // Tms of last Tx access
+
+// flags
+static volatile uint8_t bufovr = 0, // input buffer overfull
+                        rxrdy  = 0, // received data ready
+                        txrdy  = 1; // transmission done
+
+// length of data (including '\n') in current buffer
+static volatile int dlen = 0;
+static volatile int odatalen[2] = {0};
+
+static uint8_t rbufno = 0, tbufno = 0; // current rbuf/tbuf numbers
+static char rbuf[2][UARTBUFSZI], tbuf[2][UARTBUFSZO]; // receive & transmit buffers
+static char *recvdata = NULL;
+
+static int transmit_tbuf();
+
+// return 1 if overflow was
+int usart_ovr(){
+    if(bufovr){
+        bufovr = 0;
+        return 1;
+    }
+    return 0;
+}
+
+// check if the buffer was filled >10ms ago (transmit it then)
+// @return rxrdy flag
+int chk_usart(){
+    if(Tms - lastAccessT > TRANSMIT_DELAY){
+        transmit_tbuf();
+        lastAccessT = Tms;
+    }
+    int ret = rxrdy;
+    rxrdy = 0;
+    return ret;
+}
+
+/**
+ * return length of received data (without trailing zero
+ */
+int usart_getline(char **line){
+    *line = recvdata;
+    rxrdy = 0;
+    recvdata = NULL;
+    bufovr = 0;
+    return dlen;
+}
+
+// transmit current tbuf and swap buffers
+static int transmit_tbuf(){
+    uint32_t p = 1000000;
+    while(!txrdy && --p);
+    if(!txrdy) return 0;
+    register int l = odatalen[tbufno];
+    if(!l) return 1;
+    txrdy = 0;
+    odatalen[tbufno] = 0;
+    DMA1_Channel4->CCR &= ~DMA_CCR_EN;
+    DMA1_Channel4->CMAR = (uint32_t) tbuf[tbufno]; // mem
+    DMA1_Channel4->CNDTR = l;
+    DMA1_Channel4->CCR |= DMA_CCR_EN;
+    tbufno = !tbufno;
+    return 1;
+}
+
+void usart_putchar(const char ch){
+    if(odatalen[tbufno] == UARTBUFSZO)
+        if(!transmit_tbuf()) return;
+    tbuf[tbufno][odatalen[tbufno]++] = ch;
+}
+
+void usart_send(const char *str){
+    while(*str){
+        if(odatalen[tbufno] == UARTBUFSZO)
+            if(!transmit_tbuf()) return;
+        tbuf[tbufno][odatalen[tbufno]++] = *str++;
+    }
+}
+
+void usart_sendn(const char *str, uint32_t L){
+    for(uint32_t i = 0; i < L; ++i){
+        if(odatalen[tbufno] == UARTBUFSZO)
+            if(!transmit_tbuf()) return;
+        tbuf[tbufno][odatalen[tbufno]++] = *str++;
+    }
+}
+
+// USART1: Rx - PA10 (AF7), Tx - PA9  (AF7)
+void usart_setup(){
+    // setup pins:
+    GPIOA->MODER = (GPIOA->MODER & ~(GPIO_MODER_MODER9 | GPIO_MODER_MODER10)) |
+                    GPIO_MODER_MODER9_AF | GPIO_MODER_MODER10_AF;
+    GPIOA->AFR[1] = (GPIOA->AFR[1] & ~(GPIO_AFRH_AFRH1 | GPIO_AFRH_AFRH2)) |
+                7 << (1 * 4) | 7 << (2 * 4); // PA9, PA10
+    // clock
+    RCC->APB2ENR |= RCC_APB2ENR_USART1EN;
+    RCC->AHBENR |= RCC_AHBENR_DMA1EN;
+    USART1->ICR = 0xffffffff; // clear all flags
+    // Tx DMA
+    DMA1_Channel4->CCR = 0;
+    DMA1_Channel4->CPAR = (uint32_t) &USART1->TDR; // periph
+    DMA1_Channel4->CCR |= DMA_CCR_MINC | DMA_CCR_DIR | DMA_CCR_TCIE; // 8bit, mem++, mem->per, transcompl irq
+    // Rx DMA
+    DMA1_Channel5->CCR = 0;
+    DMA1_Channel5->CPAR = (uint32_t) &USART1->RDR; // periph
+    DMA1_Channel5->CMAR = (uint32_t) rbuf[0];
+    DMA1_Channel5->CNDTR = UARTBUFSZI;
+    DMA1_Channel5->CCR |= DMA_CCR_MINC | DMA_CCR_TCIE | DMA_CCR_EN; // 8bit, mem++, per->mem, transcompl irq, enable
+    // setup usart
+    USART1->BRR = 720000 / 1152;
+    USART1->CR3 = USART_CR3_DMAT | USART_CR3_DMAR; // enable DMA Tx/Rx
+    USART1->CR2 = USART_CR2_ADD_VAL('\n'); // init character match register
+    USART1->CR1 = USART_CR1_TE | USART_CR1_RE | USART_CR1_UE | USART_CR1_CMIE; // 1start,8data,nstop; enable Rx,Tx,USART; enable CharacterMatch Irq
+    uint32_t tmout = 16000000;
+    while(!(USART1->ISR & USART_ISR_TC)){if(--tmout == 0) break;} // polling idle frame Transmission
+    USART1->ICR = 0xffffffff; // clear all flags again
+    NVIC_EnableIRQ(USART1_IRQn);
+    NVIC_EnableIRQ(DMA1_Channel4_IRQn);
+    NVIC_EnableIRQ(DMA1_Channel5_IRQn);
+    NVIC_SetPriority(DMA1_Channel5_IRQn, 0);
+    NVIC_SetPriority(USART1_IRQn, 4); // set character match priority lower
+}
+
+void usart_stop(){
+    RCC->APB2ENR &= ~RCC_APB2ENR_USART1EN;
+}
+
+// USART1 character match interrupt
+void usart1_exti25_isr(){
+    DMA1_Channel5->CCR &= ~DMA_CCR_EN; // temporaly disable DMA
+    USART1->ICR = USART_ICR_CMCF; // clear character match flag
+    recvdata = rbuf[rbufno];
+    register int l = UARTBUFSZI - DMA1_Channel5->CNDTR - 1;
+    if(l > 0){
+        recvdata[l] = 0;
+        dlen = l;
+        rxrdy = 1;
+    }
+    rbufno = !rbufno;
+    DMA1_Channel5->CMAR = (uint32_t) rbuf[rbufno];
+    DMA1_Channel5->CNDTR = UARTBUFSZI;
+    DMA1_Channel5->CCR |= DMA_CCR_EN;
+}
+
+// USART1 Tx complete
+void dma1_channel4_isr(){
+    DMA1->IFCR |= DMA_IFCR_CTCIF4;
+    txrdy = 1;
+}
+
+// USART1 Rx buffer overrun
+void dma1_channel5_isr(){
+    DMA1_Channel5->CCR &= ~DMA_CCR_EN;
+    DMA1->IFCR |= DMA_IFCR_CTCIF5;
+    DMA1_Channel5->CMAR = (uint32_t) rbuf[rbufno];
+    DMA1_Channel5->CNDTR = UARTBUFSZI;
+    bufovr = 1;
+    DMA1_Channel5->CCR |= DMA_CCR_EN;
+}
diff --git a/F303-nolib/usart1fullDMA/usart.h b/F303-nolib/usart1fullDMA/usart.h
new file mode 100644
index 0000000..13dd6e2
--- /dev/null
+++ b/F303-nolib/usart1fullDMA/usart.h
@@ -0,0 +1,52 @@
+/*
+ * This file is part of the F303usartDMA project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+#ifndef __USART_H__
+#define __USART_H__
+
+#include "hardware.h"
+
+// max pause (ms) from buffer filling and data transmitting
+#define TRANSMIT_DELAY  (15)
+
+// input and output buffers size (don't forget trailing zero in input buffer!)
+// DMA generates TC irq while last byte isn't in buffer, so, to get 80 symbols excluding '\n' we need 82 bytes in buffer
+#define UARTBUFSZI  (82)
+#define UARTBUFSZO  (80)
+
+// timeout between data bytes
+#ifndef TIMEOUT_MS
+#define TIMEOUT_MS (1500)
+#endif
+
+// macro for static strings
+#define SEND(str) usart_send(str)
+
+#define newline()   usart_putchar('\n')
+
+int usart_ovr();
+int chk_usart();
+void usart_setup();
+int usart_getline(char **line);
+void usart_send(const char *str);
+void usart_sendn(const char *str, uint32_t L);
+void usart_putchar(const char ch);
+void usart_stop();
+
+#endif // __USART_H__