HAL USART DMA

串口使用DMA的方式来接收数据和发送数据。

参考官方的工程文件，文件位置记录一下：

Z:\2022-YS\YH-F407-Guang-fang-lib\STM32Cube_FW_F4_V1.27.1\Projects\STM32F401-Discovery\Examples\UART\UART_TwoBoards_ComIT

1.串口和DMA初始化

/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file    usart.c
  * @brief   This file provides code for the configuration
  *          of the USART instances.
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2024 STMicroelectronics.
  * All rights reserved.
  *
  * This software is licensed under terms that can be found in the LICENSE file
  * in the root directory of this software component.
  * If no LICENSE file comes with this software, it is provided AS-IS.
  *
  ******************************************************************************
  */
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "usart.h"

/* USER CODE BEGIN 0 */

/* USER CODE END 0 */

UART_HandleTypeDef huart2;
DMA_HandleTypeDef hdma_usart2_tx;
DMA_HandleTypeDef hdma_usart2_rx;

/* USART2 init function */

void MX_USART2_UART_Init(void)
{

  /* USER CODE BEGIN USART2_Init 0 */

  /* USER CODE END USART2_Init 0 */

  /* USER CODE BEGIN USART2_Init 1 */

  /* USER CODE END USART2_Init 1 */
  huart2.Instance = USART2;
  huart2.Init.BaudRate = 115200;
  huart2.Init.WordLength = UART_WORDLENGTH_8B;
  huart2.Init.StopBits = UART_STOPBITS_1;
  huart2.Init.Parity = UART_PARITY_NONE;
  huart2.Init.Mode = UART_MODE_TX_RX;
  huart2.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart2.Init.OverSampling = UART_OVERSAMPLING_16;
  if (HAL_UART_Init(&huart2) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN USART2_Init 2 */

  /* USER CODE END USART2_Init 2 */

}

void HAL_UART_MspInit(UART_HandleTypeDef* uartHandle)
{

  GPIO_InitTypeDef GPIO_InitStruct = {0};
  if(uartHandle->Instance==USART2)
  {
  /* USER CODE BEGIN USART2_MspInit 0 */

  /* USER CODE END USART2_MspInit 0 */
    /* USART2 clock enable */
    __HAL_RCC_USART2_CLK_ENABLE();

    __HAL_RCC_GPIOA_CLK_ENABLE();
    /**USART2 GPIO Configuration
    PA2     ------> USART2_TX
    PA3     ------> USART2_RX
    */
    GPIO_InitStruct.Pin = RS485_A_Pin|RS485_B_Pin;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
    GPIO_InitStruct.Alternate = GPIO_AF7_USART2;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

    /* USART2 DMA Init */
    /* USART2_TX Init */
    hdma_usart2_tx.Instance = DMA1_Stream6;
    hdma_usart2_tx.Init.Channel = DMA_CHANNEL_4;
    hdma_usart2_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
    hdma_usart2_tx.Init.PeriphInc = DMA_PINC_DISABLE;
    hdma_usart2_tx.Init.MemInc = DMA_MINC_ENABLE;
    hdma_usart2_tx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
    hdma_usart2_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
    hdma_usart2_tx.Init.Mode = DMA_NORMAL;
    hdma_usart2_tx.Init.Priority = DMA_PRIORITY_MEDIUM;
    hdma_usart2_tx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
    if (HAL_DMA_Init(&hdma_usart2_tx) != HAL_OK)
    {
      Error_Handler();
    }

    __HAL_LINKDMA(uartHandle,hdmatx,hdma_usart2_tx);

    /* USART2_RX Init */
    hdma_usart2_rx.Instance = DMA1_Stream5;
    hdma_usart2_rx.Init.Channel = DMA_CHANNEL_4;
    hdma_usart2_rx.Init.Direction = DMA_PERIPH_TO_MEMORY;
    hdma_usart2_rx.Init.PeriphInc = DMA_PINC_DISABLE;
    hdma_usart2_rx.Init.MemInc = DMA_MINC_ENABLE;
    hdma_usart2_rx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
    hdma_usart2_rx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
    hdma_usart2_rx.Init.Mode = DMA_NORMAL;
    hdma_usart2_rx.Init.Priority = DMA_PRIORITY_MEDIUM;
    hdma_usart2_rx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
    if (HAL_DMA_Init(&hdma_usart2_rx) != HAL_OK)
    {
      Error_Handler();
    }

    __HAL_LINKDMA(uartHandle,hdmarx,hdma_usart2_rx);

    /* USART2 interrupt Init */
    HAL_NVIC_SetPriority(USART2_IRQn, 6, 0);
    HAL_NVIC_EnableIRQ(USART2_IRQn);
  /* USER CODE BEGIN USART2_MspInit 1 */

  /* USER CODE END USART2_MspInit 1 */
  }
}

void HAL_UART_MspDeInit(UART_HandleTypeDef* uartHandle)
{

  if(uartHandle->Instance==USART2)
  {
  /* USER CODE BEGIN USART2_MspDeInit 0 */

  /* USER CODE END USART2_MspDeInit 0 */
    /* Peripheral clock disable */
    __HAL_RCC_USART2_CLK_DISABLE();

    /**USART2 GPIO Configuration
    PA2     ------> USART2_TX
    PA3     ------> USART2_RX
    */
    HAL_GPIO_DeInit(GPIOA, RS485_A_Pin|RS485_B_Pin);

    /* USART2 DMA DeInit */
    HAL_DMA_DeInit(uartHandle->hdmatx);
    HAL_DMA_DeInit(uartHandle->hdmarx);

    /* USART2 interrupt Deinit */
    HAL_NVIC_DisableIRQ(USART2_IRQn);
  /* USER CODE BEGIN USART2_MspDeInit 1 */

  /* USER CODE END USART2_MspDeInit 1 */
  }
}

/* USER CODE BEGIN 1 */

/* USER CODE END 1 */

2.任务函数中进行数据的接收和发送

/******************************************************************************
* PUBLIC FUNCTIONS
******************************************************************************/
void StartTask02(void *argument)
{
	
  /* USER CODE BEGIN StartTask02 */
  /* Infinite loop */
  for(;;)
  {	
	#if 1
	RS485_RX;
	osStatus_t status;
	HAL_UART_Receive_DMA(&huart2, recv_buf, 30);
	// 等待接收一帧数据的信号量的到来
	status = osSemaphoreAcquire (myBinarySem_recvHandle, 5000);
	if(status == osOK)
	{
		// 获得一个接收一帧数据的信号量
		// 可以在这里解析这一帧数据
		#if 1
		RS485_TX;
		uint8_t hello_01[] = "hello world #######&&&&!\r\n";
		//uint8_t hello_01[] = "hello world #######&&&&!"; // 2024-08-09 是测试的电路板有问题，USART2只能接收不能发送
		HAL_UART_Transmit_DMA(&huart2, &hello_01[0], sizeof(hello_01));
		#endif
	}
	// 开始发送一帧数据回去
	#if 0
	RS485_TX;
	uint8_t hello_01[] = "hello world #######&&&& osSemaphoreAcquireHAL_UART_TxCpltCallback(UART_HandleTypeDef *huart)!\r\n";
	HAL_UART_Transmit_DMA(&huart2, hello_01, sizeof(hello_01));
	#endif
	// 等待发送一帧数据完成的信号量的到来
	status = osSemaphoreAcquire (myBinarySem_sendHandle, 5000);
	if(status == osOK)
	{
		// 说明一帧数据发送完成，可以从头来过继续接收一帧数据的到来了
	}
	#endif
	LED_S7_TOG;
    osDelay(20);// 提高执行的频率
  }
  /* USER CODE END StartTask02 *

3. 回调函数中释放信号量

/*Call legacy weak Tx complete callback*/
void HAL_UART_TxCpltCallback(UART_HandleTypeDef *huart)
{
	//LED_S1_TOG;
	osStatus_t status;
	status = osSemaphoreRelease(myBinarySem_sendHandle);
	if(status != osOK)
	{}
}

void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
	//LED_S3_TOG;
	osStatus_t status;
	status = osSemaphoreRelease(myBinarySem_recvHandle);
	if(status != osOK)
	{}
}

4. 任务函数中，接收一帧数据，然后发送一帧数据，实验效果如下图：