目录
上面讨论过,HAL_UART_Receive最容易丢数据了,可以考虑用中断来实现,但是HAL_UART_Receive_IT还不能直接用,容易数据丢失,实际工作中不会这样用,本文介绍STM32F103 HAL库函数使用并指出问题,下一篇再解释解决方案:加入环形缓冲区.
主要是两个函数的调用和实现.HAL_UART_Receive_IT和HAL_UART_RxCpltCallback(huart)
1.HAL_UART_Receive_IT:UART 并不会自动继续下一轮的接收中断配置,需要再调用重新开启HAL_UART_Receive_IT(&huart1, &g_RecvChar, 1).只是使能了中断,会启动一次中断接收,不代表收到数据了.接收1字节实时性更强,灵活性,占内存更少。
2.HAL_UART_RxCpltCallback(huart);在回调函数设置标志位,告诉已经传输完毕了.
从源头到调用回调函数的调用过程, USART1_IRQHandler->void USART1_IRQHandler(void)->void HAL_UART_IRQHandler(UART_HandleTypeDef *huart)-> UART_Receive_IT(huart)-> __HAL_UART_DISABLE_IT(huart, UART_IT_RXNE)-> HAL_UART_RxCpltCallback(huart);
一、开发环境
硬件:正点原子精英版 V2 STM32F103开发板
单片机:STM32F103ZET6
Keil版本:5.32
STM32CubeMX版本:6.9.2
STM32Cube MCU Packges版本:STM32F1xx_DFP.2.4.1
串口:USART1(PA9,PA10)
二、配置STM32CubeMX
1.启动STM32CubeMX,新建STM32CubeMX项目 :
2.选择MCU :在软件中选择你的STM32型号-STM32F103ZET6。
3.选择时钟源:
4.配置时钟:
5.使能Debug功能:Serial Wire
6.HAL库时基选择:SysTick
7.USART1配置: 选择异步模式,使能中断。
8.配置工程参数 :在Project标签页中,配置项目名称和位置,选择工具链MDK-ARM。 9.生成代码 :在Code Generator标签页中,配置工程外设文件与HAL库,勾选头文件.c和.h文件分开,然后点击Project > Generate Code生成代码。
三、代码实现与部署
main.c增加代码:
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 "usart.h"
#include "gpio.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include <string.h>
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
extern UART_HandleTypeDef huart1;
/* 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 */
void Wait_Rx_Complete(void);
char *str= "hello\r\n";
char c;
/* USER CODE END PFP */
/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
/* 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_USART1_UART_Init();
/* USER CODE BEGIN 2 */
HAL_UART_Transmit(&huart1,str,strlen(str),1000);
/* USER CODE END 2 */
/* Infinite loop */
/* USER CODE BEGIN WHILE */
while (1)
{
/* USER CODE END WHILE */
/* USER CODE BEGIN 3 */
HAL_UART_Receive_IT(&huart1,&c,1);
Wait_Rx_Complete();
HAL_UART_Transmit(&huart1, &c, 1, 1000);
//HAL_UART_Transmit(&huart1, "\r\n", 2, 1000);
}
/* USER CODE END 3 */
}
/**
* @brief System Clock Configuration
* @retval None
*/
void SystemClock_Config(void)
{
RCC_OscInitTypeDef RCC_OscInitStruct = {0};
RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
/** Initializes the RCC Oscillators according to the specified parameters
* in the RCC_OscInitTypeDef structure.
*/
RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSE;
RCC_OscInitStruct.HSEState = RCC_HSE_ON;
RCC_OscInitStruct.HSEPredivValue = RCC_HSE_PREDIV_DIV1;
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 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_DIV2;
RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != 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 */
2.usa rt.c增加代码
cpp
/* USER CODE BEGIN 1 */
static volatile int g_rx_cplt = 0;
void HAL_UART_RxCpltCallback(UART_HandleTypeDef *huart)
{
g_rx_cplt=1;
}
void Wait_Rx_Complete(void)
{
while (g_rx_cplt == 0);
g_rx_cplt = 0;
}
/* USER CODE END 1 */
3.连接USART1 :用USB转TTL工具连接当前硬件USART1的PA9、PA10,GND。
4.打开串口助手:
5.编译代码:Keil编译生成的代码。
6.烧录程序:将编译好的程序用ST-LINK烧录到STM32微控制器中。
四、运行结果:
- 屏蔽HAL_UART_Transmit(&huart1, "\r\n", 2, 1000)时候,程序编译烧录完成并运行,复位打印hello,发送1234567890时候,打印"1234567890". 正常.
2. 不屏蔽HAL_UART_Transmit(&huart1, "\r\n", 2, 1000),一旦程序烧录完成并运行,复位打印hello,发送1234567890时候,打印"1258",原因调用HAL_UART_Transmit()耗时大,没能及时的打开HAL_UART_Receive_IT中断接收数据,导致数据丢失.
五、注意事项
1.确保你的开发环境和工具已经正确安装和配置。
2.如果没有打印,按一下复位键,检查连接和电源是否正确,注意根据你所用的硬件来接线,不要接错线。
3.在串口打印数据时,要确保波特率等参数与串口助手设置一致。
通过上述步骤,介绍STM32F103 HAL库函数HAL_UART_Receive_IT的使用并指出数据丢失问题,下一篇再解释解决方案:加入环形缓冲区.