STM32串口溢出错误Overrun使用不当导致的串口死机

1. STM32串口默认是打开Overrun、DMA on RX Error

2. 使用HAL库，打开Overrun

如果出现错误，HAL库函数会关闭接收，再调用错误回调函数（用户需实现，不然串口接收不再工作，从外部看串口死机）

void HAL_UART_IRQHandler(UART_HandleTypeDef *huart)
{
      errorcode = huart->ErrorCode;
      if ((HAL_IS_BIT_SET(huart->Instance->CR3, USART_CR3_DMAR)) ||
          ((errorcode & (HAL_UART_ERROR_RTO | HAL_UART_ERROR_ORE)) != 0U))
      {
        /* Blocking error : transfer is aborted
           Set the UART state ready to be able to start again the process,
           Disable Rx Interrupts, and disable Rx DMA request, if ongoing */
        UART_EndRxTransfer(huart); 	//关闭接收

HAL_UART_ErrorCallback(huart);	//调用错误回调函数
}
}

HAL_StatusTypeDef HAL_UART_Init(UART_HandleTypeDef *huart)
{
  if (huart->AdvancedInit.AdvFeatureInit != UART_ADVFEATURE_NO_INIT)
  {
    UART_AdvFeatureConfig(huart);
  }
}

所以需在错误回调中重新开启接收

uint8_t buf[10];
void HAL_UART_ErrorCallback(UART_HandleTypeDef *huart)
{
	if(huart == &huart1)
	{
		__HAL_UNLOCK(huart);
		HAL_UART_Receive_IT(&huart1,buf,1);
}
}


/**
  * @brief Configure the UART peripheral advanced features.
  * @param huart UART handle.
  * @retval None
  */
void UART_AdvFeatureConfig(UART_HandleTypeDef *huart)
{
  /* Check whether the set of advanced features to configure is properly set */
  assert_param(IS_UART_ADVFEATURE_INIT(huart->AdvancedInit.AdvFeatureInit));



  /* if required, configure RX overrun detection disabling */
  if (HAL_IS_BIT_SET(huart->AdvancedInit.AdvFeatureInit, UART_ADVFEATURE_RXOVERRUNDISABLE_INIT))
  {
    assert_param(IS_UART_OVERRUN(huart->AdvancedInit.OverrunDisable));
    MODIFY_REG(huart->Instance->CR3, USART_CR3_OVRDIS, huart->AdvancedInit.OverrunDisable);
  }

  /* if required, configure DMA disabling on reception error */
  if (HAL_IS_BIT_SET(huart->AdvancedInit.AdvFeatureInit, UART_ADVFEATURE_DMADISABLEONERROR_INIT))
  {
    assert_param(IS_UART_ADVFEATURE_DMAONRXERROR(huart->AdvancedInit.DMADisableonRxError));
    MODIFY_REG(huart->Instance->CR3, USART_CR3_DDRE, huart->AdvancedInit.DMADisableonRxError);
  }

 
}

3. 在不使用HAL库来实现串口接收时需禁止Overrun，不然出现串口接收溢出，则串口自动关闭接收，从外部看来串口死机。