1.STM32CubeMX配置
（1）配置SYS
（2）配置RCC
（3）配置串口，此处我用的是串口4，其他串口也是一样的
（4）配置DMA，将串口4的TX和RX添加到DMA中
（5）到这里就全部配置好了，生成代码即可
2.代码编写
（1）先定义一个数组用于存储串口接收的数据。
cpp
uint8_t buffer[10]={0};（2）打开DMA接收和开启空闲中断
cpp
HAL_UART_Receive_DMA(&huart4,buffer,5); //打开串口DMA接收，此处是接收5个数据，存入到buffer这个数组中
__HAL_UART_ENABLE_IT(&huart4,UART_IT_IDLE); //开启空闲中断，进入空闲就打开中断（3）在串口中断函数中编写相关功能代码
注意：__HAL_DMA_GET_COUNTER函数获取DMA中未传输的数据个数，所以要计算DMA接收到了多少个数，需要用定义接收的数组大小减去该函数返回值。
cpp
void USART3_4_IRQHandler(void)
{
/* USER CODE BEGIN USART3_4_IRQn 0 */
if(__HAL_UART_GET_FLAG(&huart4,UART_FLAG_IDLE) != RESET) //进入空闲状态触发当前中断
{
__HAL_UART_CLEAR_IDLEFLAG(&huart4); //清除空闲中断标志位
HAL_UART_DMAStop(&huart4); //停止DMA，进入一次空闲中断表示DMA传输完成
uint8_t len = 10 - __HAL_DMA_GET_COUNTER(huart4.hdmarx); //实际上接收到的数据
HAL_UART_Transmit_DMA(&huart4,buffer,len); //发送数据到串口
HAL_UART_Receive_DMA(&huart4,buffer, 5); //打开DMA再一次接收数据
}
/* USER CODE END USART3_4_IRQn 0 */
HAL_UART_IRQHandler(&huart4);
/* USER CODE BEGIN USART3_4_IRQn 1 */
/* USER CODE END USART3_4_IRQn 1 */
}（4）贴出main.c全部代码
cpp
/* USER CODE BEGIN Header */
/**
******************************************************************************
* @file : main.c
* @brief : Main program body
******************************************************************************
* @attention
*
* Copyright (c) 2025 STMicroelectronics.
* All rights reserved.
*
* This software is licensed under terms that can be found in the LICENSE file
* in the root directory of this software component.
* If no LICENSE file comes with this software, it is provided AS-IS.
*
******************************************************************************
*/
/* USER CODE END Header */
/* Includes ------------------------------------------------------------------*/
#include "main.h"
#include "dma.h"
#include "usart.h"
#include "gpio.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
/* 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);
/* USER CODE BEGIN PFP */
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
uint8_t buffer[10]={0};
/**
* @brief This function handles USART3 and USART4 interrupts.
*/
void USART3_4_IRQHandler(void)
{
/* USER CODE BEGIN USART3_4_IRQn 0 */
if(__HAL_UART_GET_FLAG(&huart4,UART_FLAG_IDLE) != RESET) //进入空闲状态触发当前中断
{
__HAL_UART_CLEAR_IDLEFLAG(&huart4); //清除空闲中断标志位
HAL_UART_DMAStop(&huart4); //停止DMA，进入一次空闲中断表示DMA传输完成
uint8_t len = 10 - __HAL_DMA_GET_COUNTER(huart4.hdmarx); //实际上接收到的数据
HAL_UART_Transmit_DMA(&huart4,buffer,len); //发送数据到串口
HAL_UART_Receive_DMA(&huart4,buffer, 5); //打开DMA再一次接收数据
}
/* USER CODE END USART3_4_IRQn 0 */
HAL_UART_IRQHandler(&huart4);
/* USER CODE BEGIN USART3_4_IRQn 1 */
/* USER CODE END USART3_4_IRQn 1 */
}
/* 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_USART4_UART_Init();
/* USER CODE BEGIN 2 */
HAL_UART_Receive_DMA(&huart4,buffer,5); //打开串口DMA接收，此处是接收5个数据，存入到buffer这个数组中
__HAL_UART_ENABLE_IT(&huart4,UART_IT_IDLE); //开启空闲中断，进入空闲就打开中断
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
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};
/** Configure the main internal regulator output voltage
*/
HAL_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE1);
/** Initializes the RCC Oscillators according to the specified parameters
* in the RCC_OscInitTypeDef structure.
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI;
RCC_OscInitStruct.HSIState = RCC_HSI_ON;
RCC_OscInitStruct.HSIDiv = RCC_HSI_DIV1;
RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
RCC_OscInitStruct.PLL.PLLState = RCC_PLL_NONE;
if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
{
Error_Handler();
}
/** Initializes the CPU, AHB and APB buses clocks
*/
RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
|RCC_CLOCKTYPE_PCLK1;
RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_HSI;
RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_0) != HAL_OK)
{
Error_Handler();
}
}
/* 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 */
__disable_irq();
while (1)
{
}
/* 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,
ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
/* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */3.实现效果
串口发送什么数据就接收到什么数据。
