采用STM32H743芯片, 实现UART DMA收发数据.
用图形化的界面配置了设置, UART配置成DMA模式, 之后通过HAL_UART_Transmit_DMA发送数据, 中断报发送错误(DMA_FLAG_TEIF0_4), 总线上也没有数据输出.

以下是初始化部分代码:
static 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__);
  }
}

void HAL_UART_MspInit(UART_HandleTypeDef* huart)
{
  GPIO_InitTypeDef GPIO_InitStruct;
  if(huart->Instance==UART4)
  {
  /* USER CODE BEGIN UART4_MspInit 0 */
  /* USER CODE END UART4_MspInit 0 */
    /* Peripheral clock enable */
    __HAL_RCC_UART4_CLK_ENABLE();
  
    /**UART4 GPIO Configuration   
    PA0-WKUP     ------> UART4_TX
    PA11     ------> UART4_RX
    */
    GPIO_InitStruct.Pin = GPIO_PIN_0;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
    GPIO_InitStruct.Alternate = GPIO_AF8_UART4;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
    GPIO_InitStruct.Pin = GPIO_PIN_11;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
    GPIO_InitStruct.Alternate = GPIO_AF6_UART4;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);
    /* UART4 DMA Init */
    /* UART4_TX Init */
    hdma_uart4_tx.Instance = DMA1_Stream0;
    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(huart,hdmatx,hdma_uart4_tx);
    /* UART4_RX Init */
    hdma_uart4_rx.Instance = DMA1_Stream1;
    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;
    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(huart,hdmarx,hdma_uart4_rx);
    /* 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 */
  }
}

调用 if(HAL_UART_Transmit_DMA(&huart4, (uint8_t *)cmd_37, 1/*sizeof(cmd_37)*/)!= HAL_OK)
//if(HAL_UART_Transmit(&huart4, (uint8_t *)cmd_37, sizeof(cmd_37), 1000)!= HAL_OK)
{
  Error_Handler();
}
DMA产生了中断, 中断源是发送错误.

补充: 通过HAL_UART_Transmit(&huart4, (uint8_t *)cmd_37, sizeof(cmd_37), 1000)发送, 串口是可以正常看到数据发送的, 可以排除串口本身的问题.

现在都出H7啦，为了这个问题，看了很多帖子，但理解的不好。
猜想无非就是检查时钟配置，IO配置、复用功能配置。配置USARTx中断优先级，启用NVIC USART中断句柄。实际使用时只需把要发送的数据准备好，调用Uart_Send_Data。 Uart_Send_Data("AT+VERSION\r\n", 12);  唉，说不好了，我有空再研究研究
要不你自己参考，【STM32H743网络-----分享调试经验及注意事项】
https://www.stmcu.org.cn/module/forum/thread-615089-1-1.html
https://www.stmcu.org.cn/module/forum/thread-616379-1-1.html

feixiang20 发表于 2018-8-30 02:24
现在都出H7啦，为了这个问题，看了很多帖子，但理解的不好。
猜想无非就是检查时钟配置，IO配置、复用功能 ...

收到,谢谢

这个FIFO先关闭试看看。