基于HAL库的DMA + 空闲中断实现 uart通信（stm32f103rc）

我的工程是用cubemx直接生成的，关于用cubemx生成工程网上有很多参考资料，这里不做过多说明。只看一下我的uart配置参数即可（只付上uart2的配置，uart1的配置同样）：

cubemx生成工程后会自动添加  MX_USART1_UART_Init();MX_USART2_UART_Init();函数以及全局句柄：

UART_HandleTypeDef huart1;
UART_HandleTypeDef huart2;
DMA_HandleTypeDef hdma_usart1_rx;
DMA_HandleTypeDef hdma_usart1_tx;
DMA_HandleTypeDef hdma_usart2_tx;
DMA_HandleTypeDef hdma_usart2_rx;

在usart.c中还有cubemx自动生成的HAL_UART_MspInit（）；HAL_UART_MspDeInit（）；函数，这些函数的调用过程是这样的：

下面讲解用户自己添加部分的代码实现：

首先，要打开空闲中断（打开中断可以放在uart初始化成后）：

    __enable_irq();
    __HAL_UART_ENABLE_IT(&huart1, UART_IT_IDLE);//开启空闲中断
    __HAL_UART_ENABLE_IT(&huart2, UART_IT_IDLE);//开启空闲中断

其次，开启DAM传输（放在打开中断之后）：

    HAL_UART_Receive_DMA(&huart1, (uint8_t*)receive_buff, 255);
    HAL_UART_Receive_DMA(&huart2, (uint8_t*)uart2_rx_buf, 255);//开启DMA传输

然后，定义串口空闲中断处理函数：在串口中断中添加串口空闲中断处理函数（cubemx生成的工程所有的中断都会放在stm32f1xx_it.c中）

最后，定义串口空闲中断回调函数：用以标记数据接收完成， data_length是uart1接收到的数据长度，data_len2是uart2接收到的数据长度，uart1用receive_buff进行接收数据，uart2用uart1_rx_buf进行接收数据：

这样，uart+DMA+空闲中断接收数据代码就完全实现了。

有一点说明一下，我用的是基于rtthread的工程，所以打印函数用的是rt_kprintf()函数。如果是裸机工程的话，可以在usart.c中添加如下函数实现printf()函数打印：

下面将裸机工程的代码全部粘贴进来吧：

main.c代码：

/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; Copyright (c) 2020 STMicroelectronics.
  * All rights reserved.</center></h2>
  *
  * This software component is licensed by ST under BSD 3-Clause license,
  * the "License"; You may not use this file except in compliance with the
  * License. You may obtain a copy of the License at:
  *                        opensource.org/licenses/BSD-3-Clause
  *
  ******************************************************************************
  */
/* USER CODE END Header */

/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "dma.h"
#include "rtc.h"
#include "usart.h"
#include "gpio.h"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "sim8xx.h"
#include "stm32f1xx_hal_gpio.h"
#include "delay.h"
/* USER CODE END Includes */

/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */

/* USER CODE END PTD */

/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
/* USER CODE END PD */

/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */

/* USER CODE END PM */

/* Private variables ---------------------------------------------------------*/

/* USER CODE BEGIN PV */

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_NVIC_Init(void);
/* USER CODE BEGIN PFP */

/* USER CODE END PFP */

    /* Private user code ---------------------------------------------------------*/
    /* USER CODE BEGIN 0 */
    uint8_t receive_buff[255];                //定义接收数组
    uint8_t receive_buff2[255];                //定义接收数组

    void MCU_SysInit(void)
    {
        __enable_irq();
        __HAL_UART_ENABLE_IT(&huart1, UART_IT_IDLE);//开启空闲中断
        __HAL_UART_ENABLE_IT(&huart2, UART_IT_IDLE);//开启空闲中断
    }
    /* USER CODE END 0 */

/**
  * @brief  The application entry point.
  * @retval int
  */
int main(void)
{
  /* USER CODE BEGIN 1 */

  /* USER CODE END 1 */

  /* MCU Configuration--------------------------------------------------------*/

  /* Reset of all peripherals, Initializes the Flash interface and the Systick. */
  HAL_Init();

  /* USER CODE BEGIN Init */

  /* USER CODE END Init */

  /* Configure the system clock */
  SystemClock_Config();

  /* USER CODE BEGIN SysInit */

  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  MX_GPIO_Init();
  MX_DMA_Init();
  MX_USART1_UART_Init();
  MX_USART2_UART_Init();
  MX_RTC_Init();

      /* Initialize interrupts */
      MX_NVIC_Init();
      /* USER CODE BEGIN 2 */
      MCU_SysInit();
      int res=0;
      /* USER CODE END 2 */
     

      /* Infinite loop */
      /* USER CODE BEGIN WHILE */
      //开启DMA传输
      HAL_UART_Receive_DMA(&huart1, (uint8_t*)receive_buff, 255);     //设置DMA传输，将串口1的数据搬运到recvive_buff中，//每次255个字节                                                                    
      HAL_UART_Receive_DMA(&huart2, (uint8_t*)receive_buff2, 255);     //设置DMA传输，将串口2的数据搬运到recvive_buff2中，//每次255个字节
      sim8xx_pwr_off();
      delay_ms(2);
      sim8xx_pwr_on();
      res = sim8xx_get_status();
      while(!res){
        res = sim8xx_get_status();
      }
      printf("sim8xx status =  %d.\r\n",res);
      delay_ms(20);
      sim8xx_write("ATE0\r\n",6);
      delay_ms(2000);
      sim8xx_write("AT+CPIN?\r\n",10);
      while (1)
      {
        /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */
  }
  /* USER CODE END 3 */
}

/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
  RCC_PeriphCLKInitTypeDef PeriphClkInit = {0};

  /** Initializes the CPU, AHB and APB busses clocks
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE|RCC_OSCILLATORTYPE_LSE;
  RCC_OscInitStruct.HSEState = RCC_HSE_ON;
  RCC_OscInitStruct.HSEPredivValue = RCC_HSE_PREDIV_DIV1;
  RCC_OscInitStruct.LSEState = RCC_LSE_ON;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSE;
  RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL9;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }
  /** Initializes the CPU, AHB and APB busses clocks
  */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                              |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV2;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
  {
    Error_Handler();
  }
  PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_RTC;
  PeriphClkInit.RTCClockSelection = RCC_RTCCLKSOURCE_LSE;
  if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK)
  {
    Error_Handler();
  }
}

/**
  * @brief NVIC Configuration.
  * @retval None
  */
static void MX_NVIC_Init(void)
{
  /* USART1_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(USART1_IRQn, 0, 0);
  HAL_NVIC_EnableIRQ(USART1_IRQn);
  /* USART2_IRQn interrupt configuration */
  HAL_NVIC_SetPriority(USART2_IRQn, 0, 0);
  HAL_NVIC_EnableIRQ(USART2_IRQn);
}

/* USER CODE BEGIN 4 */

/* USER CODE END 4 */

/**
  * @brief  This function is executed in case of error occurrence.
  * @retval None
  */
void Error_Handler(void)
{
  /* USER CODE BEGIN Error_Handler_Debug */
  /* User can add his own implementation to report the HAL error return state */

  /* USER CODE END Error_Handler_Debug */
}

#ifdef  USE_FULL_ASSERT
/**
  * @brief  Reports the name of the source file and the source line number
  *         where the assert_param error has occurred.
  * @param  file: pointer to the source file name
  * @param  line: assert_param error line source number
  * @retval None
  */
void assert_failed(uint8_t *file, uint32_t line)
{
  /* USER CODE BEGIN 6 */
  /* User can add his own implementation to report the file name and line number,
     tex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
  /* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */

/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

usart.h代码：

/**
  ******************************************************************************
  * File Name          : USART.h
  * Description        : This file provides code for the configuration
  *                      of the USART instances.
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; Copyright (c) 2020 STMicroelectronics.
  * All rights reserved.</center></h2>
  *
  * This software component is licensed by ST under BSD 3-Clause license,
  * the "License"; You may not use this file except in compliance with the
  * License. You may obtain a copy of the License at:
  *                        opensource.org/licenses/BSD-3-Clause
  *
  ******************************************************************************
  */
/* Define to prevent recursive inclusion -------------------------------------*/
#ifndef __usart_H
#define __usart_H
#ifdef __cplusplus
 extern "C" {
#endif

/* Includes ------------------------------------------------------------------*/
#include "main.h"

/* USER CODE BEGIN Includes */

/* USER CODE END Includes */

extern UART_HandleTypeDef huart1;
extern UART_HandleTypeDef huart2;

/* USER CODE BEGIN Private defines */
#define  BUFFER_SIZE  (255)
/* USER CODE END Private defines */

void MX_USART1_UART_Init(void);
void MX_USART2_UART_Init(void);

/* USER CODE BEGIN Prototypes */
void USER_UART_IRQHandler(UART_HandleTypeDef *huart);
void USAR_UART_IDLECallback(UART_HandleTypeDef *huart);
/* USER CODE END Prototypes */

#ifdef __cplusplus
}
#endif
#endif /*__ usart_H */

/**
  * @}
  */

/**
  * @}
  */

/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

usart.c代码：

/**
  ******************************************************************************
  * File Name          : USART.c
  * Description        : This file provides code for the configuration
  *                      of the USART instances.
  ******************************************************************************
  * @attention
  *
  * <h2><center>&copy; Copyright (c) 2020 STMicroelectronics.
  * All rights reserved.</center></h2>
  *
  * This software component is licensed by ST under BSD 3-Clause license,
  * the "License"; You may not use this file except in compliance with the
  * License. You may obtain a copy of the License at:
  *                        opensource.org/licenses/BSD-3-Clause
  *
  ******************************************************************************
  */

/* Includes ------------------------------------------------------------------*/
#include "usart.h"

    /* USER CODE BEGIN 0 */
    #include <string.h>
    #include <stdio.h>
    extern uint8_t receive_buff[BUFFER_SIZE];                                                //接收缓冲区
    extern uint8_t receive_buff2[255];                //定义接收数组
    //Define Debug Port
    #ifdef __GNUC__
    #define PUTCHAR_PROTOTYPE int __io_putchar(int ch)
    #else
    #define PUTCHAR_PROTOTYPE int fputc(int ch, FILE *f)
    #endif
    PUTCHAR_PROTOTYPE
    {
        HAL_UART_Transmit(&huart1, (uint8_t *)&ch, 1, 0xFFFF);
        return ch;
    }
    /* USER CODE END 0 */

    UART_HandleTypeDef huart1;
    UART_HandleTypeDef huart2;
    DMA_HandleTypeDef hdma_usart1_rx;
    DMA_HandleTypeDef hdma_usart1_tx;
    DMA_HandleTypeDef hdma_usart2_rx;
    DMA_HandleTypeDef hdma_usart2_tx;

/* USART1 init function */

void MX_USART1_UART_Init(void)
{

      huart1.Instance        = USART1;
      huart1.Init.BaudRate   = 115200;
      huart1.Init.WordLength = UART_WORDLENGTH_8B;
      huart1.Init.StopBits   = UART_STOPBITS_1;
      huart1.Init.Parity     = UART_PARITY_NONE;
      huart1.Init.Mode       = UART_MODE_TX_RX;
      huart1.Init.HwFlowCtl  = UART_HWCONTROL_NONE;
      huart1.Init.OverSampling    = UART_OVERSAMPLING_16;
      if (HAL_UART_Init(&huart1) != HAL_OK)
      {
        Error_Handler();
      }

}
/* USART2 init function */

void MX_USART2_UART_Init(void)
{

      huart2.Instance         = USART2;
      huart2.Init.BaudRate    = 115200;
      huart2.Init.WordLength  = UART_WORDLENGTH_8B;
      huart2.Init.StopBits    = UART_STOPBITS_1;
      huart2.Init.Parity      = UART_PARITY_NONE;
      huart2.Init.Mode        = UART_MODE_TX_RX;
      huart2.Init.HwFlowCtl   = UART_HWCONTROL_NONE;
      huart2.Init.OverSampling    = UART_OVERSAMPLING_16;
      if (HAL_UART_Init(&huart2) != HAL_OK)
      {
        Error_Handler();
      }

}

void HAL_UART_MspInit(UART_HandleTypeDef* uartHandle)
{

  GPIO_InitTypeDef GPIO_InitStruct = {0};
  if(uartHandle->Instance==USART1)
  {
  /* USER CODE BEGIN USART1_MspInit 0 */

  /* USER CODE END USART1_MspInit 0 */
    /* USART1 clock enable */
    __HAL_RCC_USART1_CLK_ENABLE();
 
    __HAL_RCC_GPIOA_CLK_ENABLE();
    /**USART1 GPIO Configuration    
    PA9     ------> USART1_TX
    PA10     ------> USART1_RX
    */
    GPIO_InitStruct.Pin   = GPIO_PIN_9;
    GPIO_InitStruct.Mode  = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

    GPIO_InitStruct.Pin  = GPIO_PIN_10;
    GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

        /* USART1 DMA Init */
        /* USART1_RX Init */
        hdma_usart1_rx.Instance = DMA1_Channel5;
        hdma_usart1_rx.Init.Direction = DMA_PERIPH_TO_MEMORY;
        hdma_usart1_rx.Init.PeriphInc = DMA_PINC_DISABLE;
        hdma_usart1_rx.Init.MemInc = DMA_MINC_ENABLE;
        hdma_usart1_rx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
        hdma_usart1_rx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
        hdma_usart1_rx.Init.Mode = DMA_CIRCULAR;
        hdma_usart1_rx.Init.Priority = DMA_PRIORITY_LOW;
        if (HAL_DMA_Init(&hdma_usart1_rx) != HAL_OK)
        {
          Error_Handler();
        }

    __HAL_LINKDMA(uartHandle,hdmarx,hdma_usart1_rx);

        /* USART1_TX Init */
        hdma_usart1_tx.Instance = DMA1_Channel4;
        hdma_usart1_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
        hdma_usart1_tx.Init.PeriphInc = DMA_PINC_DISABLE;
        hdma_usart1_tx.Init.MemInc = DMA_MINC_ENABLE;
        hdma_usart1_tx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
        hdma_usart1_tx.Init.MemDataAlignment = DMA_MDATAALIGN_BYTE;
        hdma_usart1_tx.Init.Mode = DMA_CIRCULAR;
        hdma_usart1_tx.Init.Priority = DMA_PRIORITY_LOW;
        if (HAL_DMA_Init(&hdma_usart1_tx) != HAL_OK)
        {
          Error_Handler();
        }

    __HAL_LINKDMA(uartHandle,hdmatx,hdma_usart1_tx);

  /* USER CODE BEGIN USART1_MspInit 1 */

  /* USER CODE END USART1_MspInit 1 */
  }
  else if(uartHandle->Instance==USART2)
  {
  /* USER CODE BEGIN USART2_MspInit 0 */

  /* USER CODE END USART2_MspInit 0 */
    /* USART2 clock enable */
    __HAL_RCC_USART2_CLK_ENABLE();
 
    __HAL_RCC_GPIOA_CLK_ENABLE();
    /**USART2 GPIO Configuration    
    PA2     ------> USART2_TX
    PA3     ------> USART2_RX
    */
    GPIO_InitStruct.Pin   = GPIO_PIN_2;
    GPIO_InitStruct.Mode  = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_HIGH;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

    GPIO_InitStruct.Pin  = GPIO_PIN_3;
    GPIO_InitStruct.Mode = GPIO_MODE_INPUT;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

    /* USART2 DMA Init */
    /* USART2_RX Init */
    hdma_usart2_rx.Instance       = DMA1_Channel6;
    hdma_usart2_rx.Init.Direction = DMA_PERIPH_TO_MEMORY;
    hdma_usart2_rx.Init.PeriphInc = DMA_PINC_DISABLE;
    hdma_usart2_rx.Init.MemInc    = DMA_MINC_ENABLE;
    hdma_usart2_rx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
    hdma_usart2_rx.Init.MemDataAlignment    = DMA_MDATAALIGN_BYTE;
    hdma_usart2_rx.Init.Mode                = DMA_CIRCULAR;
    hdma_usart2_rx.Init.Priority            = DMA_PRIORITY_LOW;
    if (HAL_DMA_Init(&hdma_usart2_rx) != HAL_OK)
    {
      Error_Handler();
    }

    __HAL_LINKDMA(uartHandle,hdmarx,hdma_usart2_rx);

    /* USART2_TX Init */
    hdma_usart2_tx.Instance       = DMA1_Channel7;
    hdma_usart2_tx.Init.Direction = DMA_MEMORY_TO_PERIPH;
    hdma_usart2_tx.Init.PeriphInc = DMA_PINC_DISABLE;
    hdma_usart2_tx.Init.MemInc    = DMA_MINC_ENABLE;
    hdma_usart2_tx.Init.PeriphDataAlignment = DMA_PDATAALIGN_BYTE;
    hdma_usart2_tx.Init.MemDataAlignment    = DMA_MDATAALIGN_BYTE;
    hdma_usart2_tx.Init.Mode                = DMA_CIRCULAR;
    hdma_usart2_tx.Init.Priority            = DMA_PRIORITY_LOW;
    if (HAL_DMA_Init(&hdma_usart2_tx) != HAL_OK)
    {
      Error_Handler();
    }

    __HAL_LINKDMA(uartHandle,hdmatx,hdma_usart2_tx);

  /* USER CODE BEGIN USART2_MspInit 1 */

  /* USER CODE END USART2_MspInit 1 */
  }
}

void HAL_UART_MspDeInit(UART_HandleTypeDef* uartHandle)
{

  if(uartHandle->Instance==USART1)
  {
  /* USER CODE BEGIN USART1_MspDeInit 0 */

  /* USER CODE END USART1_MspDeInit 0 */
    /* Peripheral clock disable */
    __HAL_RCC_USART1_CLK_DISABLE();
 
    /**USART1 GPIO Configuration    
    PA9     ------> USART1_TX
    PA10     ------> USART1_RX
    */
    HAL_GPIO_DeInit(GPIOA, GPIO_PIN_9|GPIO_PIN_10);

    /* USART1 DMA DeInit */
    HAL_DMA_DeInit(uartHandle->hdmarx);
    HAL_DMA_DeInit(uartHandle->hdmatx);

    /* USART1 interrupt Deinit */
    HAL_NVIC_DisableIRQ(USART1_IRQn);
  /* USER CODE BEGIN USART1_MspDeInit 1 */

  /* USER CODE END USART1_MspDeInit 1 */
  }
  else if(uartHandle->Instance==USART2)
  {
  /* USER CODE BEGIN USART2_MspDeInit 0 */

  /* USER CODE END USART2_MspDeInit 0 */
    /* Peripheral clock disable */
    __HAL_RCC_USART2_CLK_DISABLE();
 
    /**USART2 GPIO Configuration    
    PA2     ------> USART2_TX
    PA3     ------> USART2_RX
    */
    HAL_GPIO_DeInit(GPIOA, GPIO_PIN_2|GPIO_PIN_3);

    /* USART2 DMA DeInit */
    HAL_DMA_DeInit(uartHandle->hdmarx);
    HAL_DMA_DeInit(uartHandle->hdmatx);

    /* USART2 interrupt Deinit */
    HAL_NVIC_DisableIRQ(USART2_IRQn);
  /* USER CODE BEGIN USART2_MspDeInit 1 */

  /* USER CODE END USART2_MspDeInit 1 */
  }
}

    /* USER CODE BEGIN 1 */
    void USAR_UART_IDLECallback(UART_HandleTypeDef *huart)
    {
        if(USART1 == huart->Instance){
            HAL_UART_DMAStop(&huart1);                                                     //停止本次DMA传输
        
            uint8_t data_length  = BUFFER_SIZE - __HAL_DMA_GET_COUNTER(&hdma_usart1_rx);   //计算接收到的数据长度

            printf("uart1 Receive Data(length = %d): ",data_length);
             //测试函数：将接收到的数据打印出去
            HAL_UART_Transmit(&huart1,receive_buff,data_length,0x200);                    
            HAL_UART_Transmit_DMA(&huart2,receive_buff,data_length); //测试函数：将接收到的数据发送到串口2
            printf("\r\n");

            memset(receive_buff,0,data_length);                                            //清零接收缓冲区
            data_length = 0;
            HAL_UART_Receive_DMA(&huart1, (uint8_t*)receive_buff, 255);//重启开始DMA传输 每次255字节数据
        }
        else if(USART2 == huart->Instance){
            HAL_UART_DMAStop(&huart2);                                                     //停止本次DMA传输
        
            uint8_t data_length2  = BUFFER_SIZE - __HAL_DMA_GET_COUNTER(&hdma_usart2_rx);   //计算接收到的数据长度

            printf("uart2 Receive Data(length = %d): ",data_length2);
            /*测试函数：将接收到的数据通过串口1打印出去*/
            HAL_UART_Transmit(&huart1,receive_buff2,data_length2,0x200);                     
            printf("\r\n");

            memset(receive_buff2,0,data_length2);                                            //清零接收缓冲区
            data_length2 = 0;
            HAL_UART_Receive_DMA(&huart2, (uint8_t*)receive_buff2, 255); //重启开始DMA传输 每次255字节数据
        }
    }
    void USER_UART_IRQHandler(UART_HandleTypeDef *huart)
    {
        if(USART1 == huart->Instance)                                   //判断是否是串口1
        {
            if(RESET != __HAL_UART_GET_FLAG(&huart1, UART_FLAG_IDLE))   //判断是否是空闲中断
            {
                __HAL_UART_CLEAR_IDLEFLAG(&huart1);                     //清楚空闲中断标志（否则会一直不断进入中断）
                printf("\r\nUART1 Idle IQR Detected\r\n");
                USAR_UART_IDLECallback(huart);                          //调用中断处理函数
            }
        }
        else if(USART2 == huart->Instance)                              //判断是否是串口2
        {
            if(RESET != __HAL_UART_GET_FLAG(&huart2, UART_FLAG_IDLE))   //判断是否是空闲中断
            {
                __HAL_UART_CLEAR_IDLEFLAG(&huart2);  //清楚空闲中断标志（否则会一直不断进入中断）
                printf("\r\nUART2 Idle IQR Detected\r\n");
                USAR_UART_IDLECallback(huart);                          //调用中断处理函数
            }
        }
    }
    /* USER CODE END 1 */

/************************ (C) COPYRIGHT STMicroelectronics *****END OF FILE****/

stm32f1xx_it.c的代码：

引入句柄：

添加的用户中断函数，stm32f1xx_it.c其他地方没做修改。