STM32F103用hal库使用DMA+串口空闲中断接收数据

简介：

出现空闲标志时，认为一帧报文发送完毕，进行报文分析，比普通的串口中断效率高很多！

用到的工具：CubeMX，Keil5

芯片：STM32F103VET6

步骤：

一、配置串口

二、使能串口NVIC中断

三、配置DMA

四、配置为MDK5，并生成代码工程

五、打开工程，添加部分代码

uint8_t receive_buff[255];                //定义接收数组
int main(void)
{
  /* USER CODE BEGIN 1 */

  /* USER CODE END 1 */

  /* MCU Configuration--------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();

  /* USER CODE BEGIN Init */

  /* USER CODE END Init */

  /* Configure the system clock */
  SystemClock_Config();

  /* USER CODE BEGIN SysInit */

  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_DMA_Init();
  MX_USART1_UART_Init();
  /* USER CODE BEGIN 2 */
	__HAL_UART_ENABLE_IT(&huart1, UART_IT_IDLE);
	HAL_UART_Receive_DMA(&huart1, (uint8_t*)receive_buff, 255); 
  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */
  }
  /* USER CODE END 3 */
}

六、添加串口空闲中断处理

/**
  * @brief This function handles USART1 global interrupt.
  */
void USART1_IRQHandler(void)
{
  /* USER CODE BEGIN USART1_IRQn 1 */
	if(RESET != __HAL_UART_GET_FLAG(&huart1, UART_FLAG_IDLE))   //判断是否是空闲中断
	{
		__HAL_UART_CLEAR_IDLEFLAG(&huart1);                       //清除空闲中断标志
		HAL_UART_DMAStop(&huart1);                                //停止本次DMA传输    
		uint8_t data_length  = 255 - __HAL_DMA_GET_COUNTER(&hdma_usart1_rx);   //计算接收到的数据长度
		HAL_UART_Transmit(&huart1,receive_buff,data_length,0x200);             //测试函数：将接收到的数据打印出去
		memset(receive_buff,0,data_length);                                            
		data_length = 0;
		HAL_UART_Receive_DMA(&huart1, (uint8_t*)receive_buff, 255);                    //重启开始DMA传输
	}
  /* USER CODE END USART1_IRQn 1 */
}

七、连接串口助手测试

收到数据后，会在空闲中断里把收到的数据发送回去。效果如下图所示：

以下为把串口空闲中断抽离出来：以串口2为例：

UART_HandleTypeDef huart2;
uint8_t receive_buff2[255];
DMA_HandleTypeDef hdma_usart2_rx;

void Uart2_Init()
{
	__HAL_RCC_GPIOA_CLK_ENABLE();
	__HAL_RCC_AFIO_CLK_ENABLE();
  __HAL_RCC_PWR_CLK_ENABLE();
	__HAL_RCC_USART2_CLK_ENABLE();
	__HAL_RCC_DMA1_CLK_ENABLE();
	HAL_NVIC_SetPriorityGrouping(NVIC_PRIORITYGROUP_4);
	
	HAL_NVIC_SetPriority(DMA1_Channel6_IRQn, 0, 0);
  HAL_NVIC_EnableIRQ(DMA1_Channel6_IRQn);
	
	GPIO_InitTypeDef GPIO_InitStruct = {0};
	GPIO_InitStruct.Pin = GPIO_PIN_2;
	GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
	GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
	HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

	GPIO_InitStruct.Pin = GPIO_PIN_3;
	GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
	GPIO_InitStruct.Pull = GPIO_PULLUP;
	HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
	
	/* USART2 DMA Init */
    /* USART2_RX Init */
	hdma_usart2_rx.Instance = DMA1_Channel6;
	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_LOW;
	if (HAL_DMA_Init(&hdma_usart2_rx) != HAL_OK)
	{
		Error_Handler();
	}

	__HAL_LINKDMA(&huart2,hdmarx,hdma_usart2_rx);

	/* USART2 interrupt Init */
	HAL_NVIC_SetPriority(USART2_IRQn, 0, 0);
	HAL_NVIC_EnableIRQ(USART2_IRQn);
	
	
	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();
  }
	__HAL_UART_ENABLE_IT(&huart2, UART_IT_IDLE);
	HAL_UART_Receive_DMA(&huart2, (uint8_t*)receive_buff2, 255); 	  
}

/**
  * @brief This function handles USART2 global interrupt.
  */
uint8_t data_length;
void USART2_IRQHandler(void)
{
	if(RESET != __HAL_UART_GET_FLAG(&huart2, UART_FLAG_IDLE))   //判断是否是空闲中断
	{
		__HAL_UART_CLEAR_IDLEFLAG(&huart2);                       //清除空闲中断标志
		HAL_UART_DMAStop(&huart2);                                //停止本次DMA传输    
		data_length  = 255 - __HAL_DMA_GET_COUNTER(&hdma_usart2_rx);   //计算接收到的数据长度
		HAL_UART_Transmit(&huart2,receive_buff2,data_length,0x200);             //测试函数：将接收到的数据打印出去
//		memset(receive_buff2,0,data_length);                                            
		HAL_UART_Receive_DMA(&huart2, (uint8_t*)receive_buff2, 255);                    //重启开始DMA传输
	}
}

main里调用初始化即可

int main(void)
{
    int count = 1;
    Uart2_Init();
    while (1)
    {
        ...
    }
}