diff --git a/f1/usart/include/usart2.h b/f1/usart/include/usart2.h
new file mode 100644
index 0000000000000000000000000000000000000000..9889d0be2c0416414e568e19b458fcd1e560d187
--- /dev/null
+++ b/f1/usart/include/usart2.h
@@ -0,0 +1,22 @@
+#ifndef USART2_F1_H
+#define USART2_F1_H
+
+#include "stm32f1xx_hal.h"
+#include "usart_common.h"
+#include "comm.h"
+
+/* public functions */
+void usart2_init(TComm *comm_dev,UART_InitTypeDef *conf,TUSART_IRQ_Priorities *priorities);
+void usart2_config(TComm *comm_dev,UART_InitTypeDef *conf);
+void usart2_set_priorities(TComm *comm_dev,TUSART_IRQ_Priorities *priorities);
+/* IRQ functions */
+unsigned char usart2_send_irq(unsigned char first_byte);
+unsigned char usart2_enable_tx_irq(void);
+unsigned char usart2_receive_irq(void);
+unsigned char usart2_cancel_receive_irq(void);
+/* DMA functions */
+unsigned char usart2_send_dma(unsigned char *data,unsigned short int length);
+unsigned char usart2_receive_dma(unsigned char *data,unsigned short int length);
+unsigned char usart2_cancel_receive_dma(void);
+
+#endif
diff --git a/f1/usart/src/usart2.c b/f1/usart/src/usart2.c
new file mode 100644
index 0000000000000000000000000000000000000000..3783a81ea4d0a697c66698fc5f35df3fde58d162
--- /dev/null
+++ b/f1/usart/src/usart2.c
@@ -0,0 +1,338 @@
+#include "usart2.h"
+
+#define USART USART2
+#define USART_ENABLE_CLK __HAL_RCC_USART2_CLK_ENABLE()
+#define USART_IRQn USART2_IRQn
+#define USART_IRQHandler USART2_IRQHandler
+
+#define USART_TX_PIN GPIO_PIN_2
+#define USART_TX_GPIO_PORT GPIOA
+#define USART_ENABLE_TX_GPIO_CLK __HAL_RCC_GPIOA_CLK_ENABLE()
+
+#define USART_RX_PIN GPIO_PIN_3
+#define USART_RX_GPIO_PORT GPIOA
+#define USART_ENABLE_RX_GPIO_CLK __HAL_RCC_GPIOA_CLK_ENABLE()
+
+/* DMA configuration */
+#define USART_DMA DMA1
+#define USART_ENABLE_DMA_CLK __HAL_RCC_DMA1_CLK_ENABLE()
+
+#define USART_TX_DMA_CHANNEL DMA1_Channel7
+#define USART_RX_DMA_CHANNEL DMA1_Channel6
+
+#define USART_DMA_TX_IRQn DMA1_Channel7_IRQn
+#define USART_DMA_RX_IRQn DMA1_Channel6_IRQn
+#define USART_DMA_TX_IRQHandler DMA1_Channel7_IRQHandler
+#define USART_DMA_RX_IRQHandler DMA1_Channel6_IRQHandler
+
+// private variables
+UART_HandleTypeDef Uart2Handle;
+DMA_HandleTypeDef usart2_hdma_tx;
+DMA_HandleTypeDef usart2_hdma_rx;
+TComm *usart2_comm_dev;
+
+// interrupt handlers
+void USART_IRQHandler(void)
+{
+ unsigned char data,ret;
+ uint32_t source;
+
+ if(__HAL_UART_GET_FLAG(&Uart2Handle, UART_FLAG_RXNE) != RESET)
+ {
+ if(__HAL_UART_GET_IT_SOURCE(&Uart2Handle, UART_IT_RXNE) !=RESET)
+ {
+ __HAL_UART_CLEAR_FLAG(&Uart2Handle,UART_FLAG_RXNE);
+ data=(uint8_t)(Uart2Handle.Instance->DR & (uint8_t)0x00FF);
+ // call the reception function
+ if(!comm_do_irq_receive(usart2_comm_dev,data))
+ __HAL_UART_DISABLE_IT(&Uart2Handle, UART_IT_RXNE);
+ }
+ }
+ if(__HAL_UART_GET_FLAG(&Uart2Handle, UART_FLAG_TC) != RESET)
+ {
+ if(__HAL_UART_GET_IT_SOURCE(&Uart2Handle, UART_IT_TC) !=RESET)
+ {
+ __HAL_UART_CLEAR_FLAG(&Uart2Handle,UART_FLAG_TC);
+ ret=comm_do_irq_send(usart2_comm_dev,&data);
+ if(ret==0x01)
+ Uart2Handle.Instance->DR=data;
+ else if(ret==0x00)
+ __HAL_UART_DISABLE_IT(&Uart2Handle, UART_IT_TC);
+ }
+ }
+ if(__HAL_UART_GET_FLAG(&Uart2Handle, UART_FLAG_PE) != RESET)// parity error
+ {
+ if(__HAL_UART_GET_IT_SOURCE(&Uart2Handle, UART_IT_PE) !=RESET)
+ {
+ __HAL_UART_CLEAR_PEFLAG(&Uart2Handle);
+ }
+ }
+ source=__HAL_UART_GET_IT_SOURCE(&Uart2Handle, UART_IT_ERR);
+ if(__HAL_UART_GET_FLAG(&Uart2Handle, UART_FLAG_FE) != RESET)// frame error
+ {
+ if(source !=RESET)
+ {
+ __HAL_UART_CLEAR_FEFLAG(&Uart2Handle);
+ }
+ }
+ if(__HAL_UART_GET_FLAG(&Uart2Handle, UART_FLAG_NE) != RESET)// noise error
+ {
+ if(source !=RESET)
+ {
+ __HAL_UART_CLEAR_NEFLAG(&Uart2Handle);
+ }
+ }
+ if(__HAL_UART_GET_FLAG(&Uart2Handle, UART_FLAG_ORE) != RESET)// overrun error
+ {
+ if(source !=RESET)
+ {
+ __HAL_UART_CLEAR_OREFLAG(&Uart2Handle);
+ }
+ }
+}
+
+void USART_DMA_TX_IRQHandler(void)
+{
+ if(__HAL_DMA_GET_FLAG(Uart2Handle.hdmatx,__HAL_DMA_GET_TE_FLAG_INDEX(Uart2Handle.hdmatx)) != RESET)
+ {
+ if(__HAL_DMA_GET_IT_SOURCE(Uart2Handle.hdmatx, DMA_IT_TE) != RESET)
+ {
+ /* Disable the transfer error interrupt */
+ __HAL_DMA_DISABLE_IT(Uart2Handle.hdmatx, DMA_IT_TE);
+ /* Clear the transfer error flag */
+ __HAL_DMA_CLEAR_FLAG(Uart2Handle.hdmatx, __HAL_DMA_GET_TE_FLAG_INDEX(Uart2Handle.hdmatx));
+ }
+ }
+ if(__HAL_DMA_GET_FLAG(Uart2Handle.hdmatx,__HAL_DMA_GET_TC_FLAG_INDEX(Uart2Handle.hdmatx)) != RESET)
+ {
+ if(__HAL_DMA_GET_IT_SOURCE(Uart2Handle.hdmatx, DMA_IT_TC) != RESET)
+ {
+ /* Disable the half transfer interrupt */
+ __HAL_DMA_DISABLE_IT(Uart2Handle.hdmatx, DMA_IT_TC);
+ /* Clear the transfer complete flag */
+ __HAL_DMA_CLEAR_FLAG(Uart2Handle.hdmatx, __HAL_DMA_GET_TC_FLAG_INDEX(Uart2Handle.hdmatx));
+ CLEAR_BIT(Uart2Handle.Instance->CR3, (USART_CR3_DMAT | USART_CR3_DMAR));
+ HAL_DMA_Abort(Uart2Handle.hdmatx);
+ // call the user function
+ comm_do_dma_send(usart2_comm_dev);
+ }
+ }
+ if(__HAL_DMA_GET_FLAG(Uart2Handle.hdmatx, __HAL_DMA_GET_HT_FLAG_INDEX(Uart2Handle.hdmatx)) != RESET)
+ {
+ if(__HAL_DMA_GET_IT_SOURCE(Uart2Handle.hdmatx, DMA_IT_HT) != RESET)
+ {
+ /* Disable the half transfer interrupt */
+ __HAL_DMA_DISABLE_IT(Uart2Handle.hdmatx, DMA_IT_HT);
+ /* Clear the half transfer complete flag */
+ __HAL_DMA_CLEAR_FLAG(Uart2Handle.hdmatx, __HAL_DMA_GET_HT_FLAG_INDEX(Uart2Handle.hdmatx));
+ }
+ }
+}
+
+void USART_DMA_RX_IRQHandler(void)
+{
+ if(__HAL_DMA_GET_FLAG(Uart2Handle.hdmarx,__HAL_DMA_GET_TE_FLAG_INDEX(Uart2Handle.hdmarx)) != RESET)
+ {
+ if(__HAL_DMA_GET_IT_SOURCE(Uart2Handle.hdmarx, DMA_IT_TE) != RESET)
+ {
+ /* Disable the transfer error interrupt */
+ __HAL_DMA_DISABLE_IT(Uart2Handle.hdmarx, DMA_IT_TE);
+ /* Clear the transfer error flag */
+ __HAL_DMA_CLEAR_FLAG(Uart2Handle.hdmarx, __HAL_DMA_GET_TE_FLAG_INDEX(Uart2Handle.hdmarx));
+ }
+ }
+ if(__HAL_DMA_GET_FLAG(Uart2Handle.hdmarx,__HAL_DMA_GET_TC_FLAG_INDEX(Uart2Handle.hdmarx)) != RESET)
+ {
+ if(__HAL_DMA_GET_IT_SOURCE(Uart2Handle.hdmarx, DMA_IT_TC) != RESET)
+ {
+ /* Disable the transfer complete interrupt */
+ __HAL_DMA_DISABLE_IT(Uart2Handle.hdmarx, DMA_IT_TC);
+ /* Clear the transfer complete flag */
+ __HAL_DMA_CLEAR_FLAG(Uart2Handle.hdmarx, __HAL_DMA_GET_TC_FLAG_INDEX(Uart2Handle.hdmarx));
+ CLEAR_BIT(Uart2Handle.Instance->CR3, (USART_CR3_DMAT | USART_CR3_DMAR));
+ HAL_DMA_Abort(Uart2Handle.hdmarx);
+ // call the user function
+ comm_do_dma_receive(usart2_comm_dev);
+ }
+ }
+ if(__HAL_DMA_GET_FLAG(Uart2Handle.hdmarx, __HAL_DMA_GET_HT_FLAG_INDEX(Uart2Handle.hdmarx)) != RESET)
+ {
+ if(__HAL_DMA_GET_IT_SOURCE(Uart2Handle.hdmarx, DMA_IT_HT) != RESET)
+ {
+ /* Disable the half transfer interrupt */
+ __HAL_DMA_DISABLE_IT(Uart2Handle.hdmarx, DMA_IT_HT);
+ /* Clear the half transfer complete flag */
+ __HAL_DMA_CLEAR_FLAG(Uart2Handle.hdmarx, __HAL_DMA_GET_HT_FLAG_INDEX(Uart2Handle.hdmarx));
+ }
+ }
+}
+
+/* public functions*/
+void usart2_init(TComm *comm_dev,UART_InitTypeDef *conf,TUSART_IRQ_Priorities *priorities)
+{
+ GPIO_InitTypeDef GPIO_InitStructure;
+
+ /* Enable GPIO clock */
+ USART_ENABLE_TX_GPIO_CLK;
+ USART_ENABLE_RX_GPIO_CLK;
+ USART_ENABLE_DMA_CLK;
+ // configure the GPIO pins
+
+ /* Configure USART Tx and Rx as alternate function push-pull */
+ GPIO_InitStructure.Pin = USART_TX_PIN;
+ GPIO_InitStructure.Mode = GPIO_MODE_AF_PP;
+ GPIO_InitStructure.Pull = GPIO_PULLUP;
+ GPIO_InitStructure.Speed = GPIO_SPEED_HIGH;
+ HAL_GPIO_Init(USART_TX_GPIO_PORT, &GPIO_InitStructure);
+
+ GPIO_InitStructure.Pin = USART_RX_PIN;
+ GPIO_InitStructure.Mode = GPIO_MODE_INPUT;
+ HAL_GPIO_Init(USART_RX_GPIO_PORT, &GPIO_InitStructure);
+
+ USART_ENABLE_CLK;
+
+ Uart2Handle.Instance = USART;
+ usart2_config(comm_dev,conf);
+
+ if(comm_dev->use_dma)
+ {
+ // configure the DMA channels
+ usart2_hdma_tx.Instance = USART_TX_DMA_CHANNEL;
+ usart2_hdma_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
+ usart2_hdma_tx.Init.PeriphInc = DMA_PINC_DISABLE;
+ usart2_hdma_tx.Init.MemInc = DMA_MINC_ENABLE;
+ usart2_hdma_tx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
+ usart2_hdma_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
+ usart2_hdma_tx.Init.Mode = DMA_NORMAL;
+ usart2_hdma_tx.Init.Priority = DMA_PRIORITY_LOW;
+
+ HAL_DMA_Init(&usart2_hdma_tx);
+
+ /* Associate the initialized DMA handle to the UART handle */
+ __HAL_LINKDMA(&Uart2Handle, hdmatx, usart2_hdma_tx);
+
+ /* Configure the DMA handler for reception process */
+ usart2_hdma_rx.Instance = USART_RX_DMA_CHANNEL;
+ usart2_hdma_rx.Init.Direction = DMA_PERIPH_TO_MEMORY;
+ usart2_hdma_rx.Init.PeriphInc = DMA_PINC_DISABLE;
+ usart2_hdma_rx.Init.MemInc = DMA_MINC_ENABLE;
+ usart2_hdma_rx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
+ usart2_hdma_rx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
+ usart2_hdma_rx.Init.Mode = DMA_NORMAL;
+ usart2_hdma_rx.Init.Priority = DMA_PRIORITY_HIGH;
+
+ HAL_DMA_Init(&usart2_hdma_rx);
+
+ /* Associate the initialized DMA handle to the the UART handle */
+ __HAL_LINKDMA(&Uart2Handle, hdmarx, usart2_hdma_rx);
+ }
+ usart2_set_priorities(comm_dev,priorities);
+
+ /* Initialize the comm structure */
+ comm_dev->send_irq=usart2_send_irq;
+ comm_dev->enable_tx_irq=usart2_enable_tx_irq;
+ comm_dev->receive_irq=usart2_receive_irq;
+ comm_dev->cancel_receive_irq=usart2_cancel_receive_irq;
+ if(comm_dev->use_dma)
+ {
+ comm_dev->send_dma=usart2_send_dma;
+ comm_dev->receive_dma=usart2_receive_dma;
+ comm_dev->cancel_receive_dma=usart2_cancel_receive_dma;
+ }
+ comm_dev->irq_send_cb=0x00000000;
+ comm_dev->irq_receive_cb=0x00000000;
+ comm_dev->dma_send_cb=0x00000000;
+ comm_dev->dma_receive_cb=0x00000000;
+
+ /* initialize internal variables */
+ usart2_comm_dev=comm_dev;
+}
+
+void usart2_config(TComm *comm_dev,UART_InitTypeDef *conf)
+{
+ Uart2Handle.Init.BaudRate = conf->BaudRate;
+ Uart2Handle.Init.WordLength = conf->WordLength;
+ Uart2Handle.Init.StopBits = conf->StopBits;
+ Uart2Handle.Init.Parity = conf->Parity;
+ Uart2Handle.Init.Mode = conf->Mode;
+ Uart2Handle.Init.HwFlowCtl = conf->HwFlowCtl;
+ Uart2Handle.Init.OverSampling = conf->OverSampling;
+ HAL_UART_Init(&Uart2Handle);
+}
+
+void usart2_set_priorities(TComm *comm_dev,TUSART_IRQ_Priorities *priorities)
+{
+ HAL_NVIC_SetPriority(USART_IRQn, priorities->irq_priority,priorities->irq_subpriority);
+ HAL_NVIC_EnableIRQ(USART_IRQn);
+ if(comm_dev->use_dma)
+ {
+ HAL_NVIC_SetPriority(USART_DMA_TX_IRQn, priorities->dma_tx_priority,priorities->dma_tx_subpriority);
+ HAL_NVIC_EnableIRQ(USART_DMA_TX_IRQn);
+ HAL_NVIC_SetPriority(USART_DMA_RX_IRQn, priorities->dma_rx_priority,priorities->dma_rx_subpriority);
+ HAL_NVIC_EnableIRQ(USART_DMA_RX_IRQn);
+ }
+}
+
+/* IRQ functions */
+unsigned char usart2_send_irq(unsigned char first_byte)
+{
+ __HAL_UART_CLEAR_FLAG(&Uart2Handle,UART_FLAG_TC);
+ __HAL_UART_ENABLE_IT(&Uart2Handle, UART_IT_TC);
+ Uart2Handle.Instance->DR=first_byte;
+
+ return 0x00;
+}
+
+unsigned char usart2_enable_tx_irq(void)
+{
+ __HAL_UART_CLEAR_FLAG(&Uart2Handle,UART_FLAG_TC);
+ __HAL_UART_ENABLE_IT(&Uart2Handle, UART_IT_TC);
+
+ return 0x00;
+}
+
+unsigned char usart2_receive_irq(void)
+{
+ /* enable the rx interrupt */
+ __HAL_UART_ENABLE_IT(&Uart2Handle, UART_IT_RXNE);
+
+ return 0x00;
+}
+
+unsigned char usart2_cancel_receive_irq(void)
+{
+ /* disable the rx interrupt */
+ __HAL_UART_DISABLE_IT(&Uart2Handle, UART_IT_RXNE);
+
+ return 0x00;
+}
+
+/* DMA functions */
+unsigned char usart2_send_dma(unsigned char *data,unsigned short int length)
+{
+ HAL_DMA_Start_IT(Uart2Handle.hdmatx,(uint32_t)data,(uint32_t)&Uart2Handle.Instance->DR,length);
+ /* Clear the TC flag in the SR register by writing 0 to it */
+ __HAL_UART_CLEAR_FLAG(&Uart2Handle,UART_FLAG_TC);
+ /* Enable the DMA transfer for transmit request by setting the DMAT bit
+ in the UART CR3 register */
+ SET_BIT(Uart2Handle.Instance->CR3, USART_CR3_DMAT);
+
+ return 0x00;
+}
+
+unsigned char usart2_receive_dma(unsigned char *data,unsigned short int length)
+{
+ HAL_DMA_Start_IT(Uart2Handle.hdmarx,(uint32_t)&Uart2Handle.Instance->DR,(uint32_t)data,length);
+ SET_BIT(Uart2Handle.Instance->CR3, USART_CR3_DMAR);
+
+ return 0x00;
+}
+
+unsigned char usart2_cancel_receive_dma(void)
+{
+ CLEAR_BIT(Uart2Handle.Instance->CR3, (USART_CR3_DMAT | USART_CR3_DMAR));
+ HAL_DMA_Abort(Uart2Handle.hdmarx);
+
+ return 0x00;
+}
+