[嵌入式]串口接收不定长数据（软件判断接收完成）

CubeMX配置略，串口记得开全局中断
usart.h

#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 huart3;

/* USER CODE BEGIN Private defines */
#define RX_LEN  	  100  	   	  //最大可接受100字节
#define Temp_Size   1 					//临时缓存大小	  	
extern uint8_t  RX_BUFF[RX_LEN]; 	
extern uint8_t Temp_RX_BUFF[Temp_Size];		//缓存每次接收到的数据(1个字节)
/* USER CODE END Private defines */

void MX_USART3_UART_Init(void);

/* USER CODE BEGIN Prototypes */

/* USER CODE END Prototypes */

#ifdef __cplusplus
}
#endif

#endif /* __USART_H__ */

usart.c
初始化后记得要加！！！
HAL_UART_Receive_IT(&huart3, (uint8_t *)Temp_RX_BUFF, Temp_Size);

#include "usart.h"

/* USER CODE BEGIN 0 */
uint8_t  RX_BUFF[RX_LEN]; 	        //接收缓存区
uint8_t Temp_RX_BUFF[Temp_Size];		//缓存每次接收到的数据(1个字节)
/* USER CODE END 0 */

UART_HandleTypeDef huart3;

/* USART3 init function */

void MX_USART3_UART_Init(void)
{

  /* USER CODE BEGIN USART3_Init 0 */

  /* USER CODE END USART3_Init 0 */

  /* USER CODE BEGIN USART3_Init 1 */

  /* USER CODE END USART3_Init 1 */
  huart3.Instance = USART3;
  huart3.Init.BaudRate = 38400;
  huart3.Init.WordLength = UART_WORDLENGTH_8B;
  huart3.Init.StopBits = UART_STOPBITS_1;
  huart3.Init.Parity = UART_PARITY_NONE;
  huart3.Init.Mode = UART_MODE_TX_RX;
  huart3.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart3.Init.OverSampling = UART_OVERSAMPLING_16;
  if (HAL_UART_Init(&huart3) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN USART3_Init 2 */
	 HAL_UART_Receive_IT(&huart3, (uint8_t *)RX_BUFF, Temp_Size);
  /* USER CODE END USART3_Init 2 */
}

void HAL_UART_MspInit(UART_HandleTypeDef* uartHandle)
{

  GPIO_InitTypeDef GPIO_InitStruct = {0};
  if(uartHandle->Instance==USART3)
  {
  /* USER CODE BEGIN USART3_MspInit 0 */

  /* USER CODE END USART3_MspInit 0 */
    /* USART3 clock enable */
    __HAL_RCC_USART3_CLK_ENABLE();

    __HAL_RCC_GPIOB_CLK_ENABLE();
    /**USART3 GPIO Configuration
    PB10     ------> USART3_TX
    PB11     ------> USART3_RX
    */
    GPIO_InitStruct.Pin = GPIO_PIN_10|GPIO_PIN_11;
    GPIO_InitStruct.Mode = GPIO_MODE_AF_PP;
    GPIO_InitStruct.Pull = GPIO_NOPULL;
    GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_VERY_HIGH;
    GPIO_InitStruct.Alternate = GPIO_AF7_USART3;
    HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);

    /* USART3 interrupt Init */
    HAL_NVIC_SetPriority(USART3_IRQn, 0, 0);
    HAL_NVIC_EnableIRQ(USART3_IRQn);
  /* USER CODE BEGIN USART3_MspInit 1 */

  /* USER CODE END USART3_MspInit 1 */
  }
}
void HAL_UART_MspDeInit(UART_HandleTypeDef* uartHandle)
{

  if(uartHandle->Instance==USART3)
  {
  /* USER CODE BEGIN USART3_MspDeInit 0 */

  /* USER CODE END USART3_MspDeInit 0 */
    /* Peripheral clock disable */
    __HAL_RCC_USART3_CLK_DISABLE();

    /**USART3 GPIO Configuration
    PB10     ------> USART3_TX
    PB11     ------> USART3_RX
    */
    HAL_GPIO_DeInit(GPIOB, GPIO_PIN_10|GPIO_PIN_11);

    /* USART3 interrupt Deinit */
    HAL_NVIC_DisableIRQ(USART3_IRQn);
  /* USER CODE BEGIN USART3_MspDeInit 1 */

  /* USER CODE END USART3_MspDeInit 1 */
  }
}

stm32f4xx_it.c部分代码如下

uint16_t nrx_time; //清除时间计时,滴答定时器调用,每毫秒+1
uint8_t  rx_flag;  //接收完成标志位
uint8_t now_len;   //当前接收长度
extern UART_HandleTypeDef huart3;
void SysTick_Handler(void)
{
  /* USER CODE BEGIN SysTick_IRQn 0 */
   nrx_time++;
  /* USER CODE END SysTick_IRQn 0 */
  HAL_IncTick();
  /* USER CODE BEGIN SysTick_IRQn 1 */
    if(nrx_time>=50&&now_len!=0)
		{
		  rx_flag=1;
		  nrx_time=0;
		}
  /* USER CODE END SysTick_IRQn 1 */
}
void USART3_IRQHandler(void)
{
  /* USER CODE BEGIN USART3_IRQn 0 */

  /* USER CODE END USART3_IRQn 0 */
  HAL_UART_IRQHandler(&huart3);
  /* USER CODE BEGIN USART3_IRQn 1 */
  HAL_UART_Receive_IT(&huart3, (uint8_t *)Temp_RX_BUFF, Temp_Size);
  /* USER CODE END USART3_IRQn 1 */
}

main.c

extern uint8_t now_len;
extern uint16_t nrx_time;
extern uint8_t  rx_flag;
/* 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 */
//重定义fputc函数，利用printf发数据才重定义
int fputc(int ch, FILE *f)
{      
	while((USART3->SR&0X40)==0){};
    USART3->DR = (uint8_t) ch;      
	return ch;
}

void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
   if(huart->Instance == USART3)
	 {
		  nrx_time=0;//每次接收到就清零接收记时
		  RX_BUFF[now_len]=Temp_RX_BUFF[0];
		  now_len++;
	 }
}
/* USER CODE END 0 */

/**
  * @brief  The application entry point.
  * @retval int
  */
int main(void)
{
  /* USER CODE BEGIN 1 */
  uint8_t str_len;
  /* 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_USART3_UART_Init();
  /* USER CODE BEGIN 2 */

  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
		if(rx_flag==1)
		{
		    str_len=now_len;//一帧数据的长度
			now_len=0;//当前长度清0
			/*************
			做你要的处理
			*************/
			rx_flag=0;//接收完一帧数据
		}
    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */
  }
  /* USER CODE END 3 */
}
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  /** Configure the main internal regulator output voltage
  */
  __HAL_RCC_PWR_CLK_ENABLE();
  __HAL_PWR_VOLTAGESCALING_CONFIG(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.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
  RCC_OscInitStruct.PLL.PLLM = 8;
  RCC_OscInitStruct.PLL.PLLN = 168;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
  RCC_OscInitStruct.PLL.PLLQ = 4;
  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_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV4;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV2;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_5) != HAL_OK)
  {
    Error_Handler();
  }
}