[嵌入式]stm32串口空闲中断接收不定长数据

串口空闲中断接收不定长数据

空闲中断是接受数据后出现一个byte的高电平(空闲)状态,就会触发空闲中断.并不是空闲就会一直中断,准确的说应该是上升沿（停止位）后一个byte，如果一直是低电平是不会触发空闲中断的（会触发break中断）。
串口初始化部分采用stm32cubemx软件生成。
一、串口空闲中断加DMA方式接收

在串口初始化时开启空闲中断和DMA接收

#define BUFFER_SIZE 512          //不定长数据的最大长度，设置为100则最大长度为100
volatile int  rx_len=0;                    //接收数据长度
volatile uint8_t recv_end_flag= 0;         //接收完成标记位
uint8_t rx_buffer[BUFFER_SIZE]={0};        //接收缓存
uint8_t rx_count=0;

void HAL_UART_MspInit(UART_HandleTypeDef* uartHandle)
{
/*省略自动生成部分代码*/
  /* USER CODE BEGIN USART1_MspInit 1 */
	__HAL_UART_ENABLE_IT(&huart1,UART_IT_IDLE);
  HAL_UART_Receive_DMA(&huart1, (uint8_t*)rx_buffer, BUFFER_SIZE);   
  /* USER CODE END USART1_MspInit 1 */ 
}

void UART_IRQ(UART_HandleTypeDef *huart)/*空闲中断加DMA方式*/
{
	uint8_t ret = 0;
	if(huart->Instance == USART1)
	{	
		if(__HAL_UART_GET_FLAG(&huart1, UART_FLAG_IDLE) != RESET)
		{
			recv_end_flag = 1;
			__HAL_UART_CLEAR_IDLEFLAG(&huart1);
			HAL_UART_DMAStop(&huart1);
			rx_len =BUFFER_SIZE - __HAL_DMA_GET_COUNTER(&hdma_usart1_rx);
			HAL_UART_Receive_DMA(&huart1, (uint8_t*)rx_buffer, BUFFER_SIZE); 
		}
	}
}

串口中断函数

extern void UART_IRQ(UART_HandleTypeDef *huart);
void USART1_IRQHandler(void)
{
  /* USER CODE BEGIN USART1_IRQn 0 */	

  /* USER CODE END USART1_IRQn 0 */
  HAL_UART_IRQHandler(&huart1);
  /* USER CODE BEGIN USART1_IRQn 1 */
	UART_IRQ(&huart1);
  /* USER CODE END USART1_IRQn 1 */
}

二、串口空闲中断加接收中断方式`
初始化时开启空闲和接收中断

void HAL_UART_MspInit(UART_HandleTypeDef* uartHandle)
{
/*省略自动生成部分代码*/
  /* USER CODE BEGIN USART1_MspInit 1 */
	__HAL_UART_ENABLE_IT(&huart1,UART_IT_IDLE);
	 __HAL_UART_ENABLE_IT(&huart1,UART_IT_RXNE);
  /* USER CODE END USART1_MspInit 1 */ 
}

void UART_IRQ(UART_HandleTypeDef *huart)/*接收和空闲中断方式*/
{
	if(__HAL_UART_GET_FLAG(huart, UART_FLAG_RXNE) != RESET)
	{
		if(recv_end_flag == UART_RX_STATE_READY)
		{
			__HAL_UART_ENABLE_IT(huart, UART_IT_IDLE);
			recv_end_flag = UART_RX_STATE_START;;
			rx_len = 0;
			rx_buffer[rx_len] = huart->Instance->DR;
			rx_len++;
		}
		else if(recv_end_flag == UART_RX_STATE_START)
		{
			rx_buffer[rx_len] = huart->Instance->DR;
			rx_len++;
		}
		__HAL_UART_CLEAR_FLAG(huart, UART_FLAG_RXNE);
	}
	if(__HAL_UART_GET_FLAG(huart, UART_FLAG_IDLE) != RESET)
	{
		__HAL_UART_DISABLE_IT(huart, UART_IT_RXNE);
		__HAL_UART_DISABLE_IT(huart, UART_IT_IDLE);
		recv_end_flag = UART_RX_STATE_DEAL;
	}
}

三、数据处理

**/*DMA加空闲中断方式*/**
while(1)
  {
		if(recv_end_flag == 1)
		{
			Debugprintf("接收到数据个数：%d\r\n",rx_len);
			HAL_UART_Transmit(&huart3, rx_buffer, rx_len, 1000);/*通过串口转发出去*/
			rx_len = 0;
			recv_end_flag = 0;/*清标志位*/
			memset(rx_buffer, 0, BUFFER_SIZE);/*清buff*/
		}
  }
**/*串口空闲中断加接收中断方式*/**
while(1)
  {
		if(end_flag ==UART_RX_STATE_DEAL)
		{
			end_flag = UART_RX_STATE_READY;
			HAL_UART_Transmit(&huart1, (uint8_t*)rec_buff, rx_cnt, 0XFFFF);
			while(HAL_UART_GetState(&huart1) == HAL_UART_STATE_BUSY);
			rx_cnt = 0;
			memset(rec_buff, 0, sizeof(rec_buff));
			__HAL_UART_ENABLE_IT(&huart1, UART_IT_RXNE);
			__HAL_UART_ENABLE_IT(&huart1, UART_IT_IDLE);			
		}
    /* USER CODE END WHILE */
    /* USER CODE BEGIN 3 */
  }
  /* USER CODE END 3 */
}