本帖最后由 Switcc 于 2018-6-19 10:29 编辑

这是我在H7上面用的空闲中断+DMA，给你参考一下：

/**********初始化串口4***********/
void MX_UART4_Init(void)
{

  huart4.Instance = UART4;
  huart4.Init.BaudRate = 115200;
  huart4.Init.WordLength=UART_WORDLENGTH_8B;
  huart4.Init.StopBits = UART_STOPBITS_1;
  huart4.Init.Parity = UART_PARITY_NONE;
  huart4.Init.Mode = UART_MODE_TX_RX;
  huart4.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart4.Init.OverSampling = UART_OVERSAMPLING_16;
  huart4.Init.OneBitSampling = UART_ONE_BIT_SAMPLE_DISABLE;
  huart4.Init.Prescaler = UART_PRESCALER_DIV1;
  huart4.Init.FIFOMode = UART_FIFOMODE_DISABLE;
  huart4.Init.TXFIFOThreshold = UART_TXFIFO_THRESHOLD_1_8;
  huart4.Init.RXFIFOThreshold = UART_RXFIFO_THRESHOLD_1_8;
  huart4.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
  if (HAL_UART_Init(&huart4) != HAL_OK)
  {
    _Error_Handler(__FILE__, __LINE__);
  }
   __HAL_UART_ENABLE_IT(&huart4, UART_IT_IDLE);//使能空闲中断
        HAL_UART_Receive_DMA(&huart4, (uint8_t*)uart4Rx,UART_RECEIVE_MAX);//启动DMA接收65535个字节
}



/************DMA配置*************/
void HAL_UART_MspInit(UART_HandleTypeDef* uartHandle)
{

  GPIO_InitTypeDef GPIO_InitStruct;
  if(uartHandle->Instance==UART4)
  {
  /* USER CODE BEGIN UART4_MspInit 0 */

  /* USER CODE END UART4_MspInit 0 */
    /* UART4 clock enable */
    __HAL_RCC_UART4_CLK_ENABLE();
  
    /**UART4 GPIO Configuration   
    PC10     ------> UART4_TX
    PC11     ------> UART4_RX
    */
    GPIO_InitStruct.Pin = GPIO_PIN_10|GPIO_PIN_11;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_PULLUP;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
    GPIO_InitStruct.Alternate = GPIO_AF8_UART4;
    HAL_GPIO_Init(GPIOC, &GPIO_InitStruct);

    /* UART4 DMA Init */
    /* UART4_RX Init */
    hdma_uart4_rx.Instance = DMA1_Stream4;
    hdma_uart4_rx.Init.Request = DMA_REQUEST_UART4_RX;
    hdma_uart4_rx.Init.Direction = DMA_PERIPH_TO_MEMORY;
    hdma_uart4_rx.Init.PeriphInc = DMA_PINC_DISABLE;
    hdma_uart4_rx.Init.MemInc = DMA_MINC_ENABLE;
    hdma_uart4_rx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
    hdma_uart4_rx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
    hdma_uart4_rx.Init.Mode = DMA_CIRCULAR;//配置成normal也可以，随便
    hdma_uart4_rx.Init.Priority = DMA_PRIORITY_LOW;
    hdma_uart4_rx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
    if (HAL_DMA_Init(&hdma_uart4_rx) != HAL_OK)
    {
      _Error_Handler(__FILE__, __LINE__);
    }

    __HAL_LINKDMA(uartHandle,hdmarx,hdma_uart4_rx);

    /* UART4_TX Init */
    hdma_uart4_tx.Instance = DMA1_Stream5;
    hdma_uart4_tx.Init.Request = DMA_REQUEST_UART4_TX;
    hdma_uart4_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
    hdma_uart4_tx.Init.PeriphInc = DMA_PINC_DISABLE;
    hdma_uart4_tx.Init.MemInc = DMA_MINC_ENABLE;
    hdma_uart4_tx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
    hdma_uart4_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
    hdma_uart4_tx.Init.Mode = DMA_NORMAL;
    hdma_uart4_tx.Init.Priority = DMA_PRIORITY_LOW;
    hdma_uart4_tx.Init.FIFOMode = DMA_FIFOMODE_DISABLE;
    if (HAL_DMA_Init(&hdma_uart4_tx) != HAL_OK)
    {
      _Error_Handler(__FILE__, __LINE__);
    }

    __HAL_LINKDMA(uartHandle,hdmatx,hdma_uart4_tx);

    /* UART4 interrupt Init */
    HAL_NVIC_SetPriority(UART4_IRQn, 0, 0);
    HAL_NVIC_EnableIRQ(UART4_IRQn);
  /* USER CODE BEGIN UART4_MspInit 1 */

  /* USER CODE END UART4_MspInit 1 */
  }
}

/**
* @brief This function handles UART4 global interrupt.
*/
/**********串口4中断入口***********/
void UART4_IRQHandler(void)
{
  /* USER CODE BEGIN UART4_IRQn 0 */

  /* USER CODE END UART4_IRQn 0 */
  HAL_UART_IRQHandler(&huart4);
  /* USER CODE BEGIN UART4_IRQn 1 */
if(__HAL_UART_GET_FLAG(&huart4,UART_FLAG_IDLE)!=RESET)//判断是否是空闲中断
        {
                __HAL_UART_CLEAR_IDLEFLAG(&huart4);
                uart_rx_idle_callback(&huart4);
        }
  /* USER CODE END UART4_IRQn 1 */
}


/**************空闲中断处理***************/
void uart_rx_idle_callback(UART_HandleTypeDef *huart)
{
        uint32_t temp;
        if(huart->Instance==USART6)
        {
                uint32_t len;
                HAL_UART_DMAStop(&huart6);
                temp=((DMA_Stream_TypeDef   *)hdma_usart6_rx.Instance)->NDTR;
                //printf("%d ",UART_RECEIVE_MAX-temp);
                uart6RxLen=UART_RECEIVE_MAX-temp;
                HAL_UART_Receive_DMA(&huart6, (uint8_t*)uart6Rx,UART_RECEIVE_MAX);
        }
        else if(huart->Instance==UART4)
        {
                HAL_UART_DMAStop(&huart4);
                temp=((DMA_Stream_TypeDef   *)hdma_uart4_rx.Instance)->NDTR;
                //printf("%d ",UART_RECEIVE_MAX-temp);
                uart4RxLen=UART_RECEIVE_MAX-temp;//实际接收长度，必须小于65535
                 /**********/
                HAL_UART_Receive_DMA(&huart4, (uint8_t*)uart4Rx,UART_RECEIVE_MAX);//再次启动DMA接收
        }
}

正在做此类应用，很感谢大家的分享，受益匪浅，让新手少走好多弯路