UART_HandleTypeDef huart4;
  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.ClockPrescaler = UART_PRESCALER_DIV1;
  huart4.AdvancedInit.AdvFeatureInit = UART_ADVFEATURE_NO_INIT;
  if (HAL_UART_Init(&huart4) != HAL_OK)

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

  /* USER CODE END UART4_MspInit 0 */
    /* UART4 clock enable */
    __HAL_RCC_UART4_CLK_ENABLE();

    __HAL_RCC_GPIOI_CLK_ENABLE();
    __HAL_RCC_GPIOA_CLK_ENABLE();
    /**UART4 GPIO Configuration
    PI9     ------> UART4_RX
    PA0     ------> UART4_TX
    */
    GPIO_InitStruct.Pin = GPIO_PIN_9;
    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(GPIOI, &GPIO_InitStruct);

    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);

    /* UART4 interrupt Init */
    HAL_NVIC_SetPriority(UART4_IRQn, 1, 2);
    HAL_NVIC_EnableIRQ(UART4_IRQn);
  /* USER CODE BEGIN UART4_MspInit 1 */
  /* USER CODE END UART4_MspInit 1 */
  }

		HAL_UART_Transmit(&huart4,"222",3,2);
//发送一个字符串 


u8 num = 10;
HAL_UART_Transmit(&huart4,&num,1,2);
//发送一个数字

u16 num = 0xffde;
u8 temp;
temp = num>>8;
HAL_UART_Transmit(&huart4,&temp,1,1);
temp = num;
HAL_UART_Transmit(&huart4,&temp,1,1);
//发送一个十六位的数据

uint16_t numd[3];
HAL_UART_Receive(&huart4,numd,3,1000);
HAL_UART_Transmit(&huart4,numd,3,1);
//等一秒时间接收三位数据

	  	uint16_t numd[3];


        HAL_UART_Receive(&huart4,numd,3,1000);
		while(HAL_UART_Transmit_IT(&huart4,numd,3)==HAL_OK);

		HAL_Delay(10);    //不加延时以下数据无法使用阻塞方式发送
		num1= num23>>8;
		HAL_UART_Transmit(&huart4,&num1,1,1);
		num1 = num23;
		HAL_UART_Transmit(&huart4,&num1,1,1);

#define num 1
uint16_t numd[num];


  void UART_Init()
{

    .....
    HAL_UART_Receive_IT(&huart4,numd,num);
}
 
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart);//接收完成回调函数
{

    HAL_UART_Receive_IT(&huart,numd,num);
}

#define SEND_BUF_SIZE 6
u8 SendBuff[SEND_BUF_SIZE]="123456"; //发送数据缓冲区
UART_HandleTypeDef UART1_Handler; 
HAL_UART_Transmit_DMA(&UART1_Handler,SendBuff,SEND_BUF_SIZE);//开启DMA传输
....  //用于数据量不多的情况下可以使用此方法清除完成标志
 if(__HAL_DMA_GET_FLAG(&UART1TxDMA_Handler,DMA_FLAG_TCIF3_7))//等待DMA2_Steam7传输完成
  {
     __HAL_DMA_CLEAR_FLAG(&UART1TxDMA_Handler,DMA_FLAG_TCIF3_7);//清除DMA2_Steam7传输完成标志
     HAL_UART_DMAStop(&UART1_Handler);      //传输完成以后关闭串口DMA
									
   }
//使用中断的方法清除发送完毕标志位
//DMA初始化中开启DMA通道所在的中断
	HAL_NVIC_SetPriority(DMA2_Stream7_IRQn,0,1);
	HAL_NVIC_EnableIRQ(DMA2_Stream7_IRQn);



void XferCpltCallback()
{
	
	 if(__HAL_DMA_GET_FLAG(&UART1TxDMA_Handler,DMA_FLAG_TCIF3_7))//等待DMA2_Steam7传输完成
     {
       __HAL_DMA_CLEAR_FLAG(&UART1TxDMA_Handler,DMA_FLAG_TCIF3_7);//清除DMA2_Steam7传输完成标志
       HAL_UART_DMAStop(&UART1_Handler);      //传输完成以后关闭串口DMA
							
    }

}

void DMA2_Stream7_IRQHandler()
{
	HAL_DMA_IRQHandler(&UART1TxDMA_Handler);

}
void HAL_UART_TxCpltCallback(UART_HandleTypeDef *huart)
{

	XferCpltCallback();

}
 

#define SEND_BUF_SIZE 6
u8 SendBuff[SEND_BUF_SIZE]=""; //发送数据缓冲区
UART_HandleTypeDef UART1_Handler; 
HAL_UART_Receive_DMA(&UART1_Handler,SendBuff,SEND_BUF_SIZE);//开启DMA传输

HAL_UART_DMAPause(&UART1_Handler);

HAL_UART_DMAResume(&UART1_Handler);

HAL_UART_DMAStop(&UART1_Handler);