【STM32】HAL库中的实现（四）：RTC （实时时钟）

🕒HAL库中的实现：RTC（Real-Time Clock）实时时钟

RTC 是 STM32 的低功耗实时时钟模块，常用于：

实时时间维护（年月日时分秒）
定时唤醒
日志时间戳
闹钟功能

RTC（实时时钟）模块提供了 三个中断源，用于在不同时间条件下触发事件。这些中断在低功耗唤醒、定时任务、系统监控等场景下使用。

🕒 RTC 的三个中断源

中断类型	含义	用途	HAL支持情况
秒中断（Second Interrupt）	每秒触发一次	定时刷新、节拍事件	❌ HAL 默认未封装，需裸机配置
闹钟中断（Alarm Interrupt）	到指定时间触发一次	定时唤醒、事件提醒	✅ HAL 封装完整
溢出中断（Overflow Interrupt）	RTC 计数器溢出时触发	长时间周期事件（如每86400秒）	❌ HAL 默认未封装，需裸机配置

CubeMX配置：
在这里插入图片描述

RTC时钟秒更新中断流程：
在这里插入图片描述

🧾 业务代码配置（ RTC 秒中断功能）

配置流程：

步骤	状态	说明
RTC 初始化	✅	使用 `MX_RTC_Init()` 初始化
启用秒中断	✅	`__HAL_RTC_SECOND_ENABLE_IT(&hrtc, RTC_IT_SEC);`
中断向量启用	✅	`RTC_IRQn` 已在中断向量表中启用
回调函数实现	✅	`HAL_RTCEx_RTCEventCallback()` 已实现
中断函数转发	✅	`RTC_IRQHandler()` 中调用了 `HAL_RTCEx_RTCIRQHandler()`
时钟源配置	✅	使用 LSI，稳定性较好
获取时间	✅	每秒打印当前时间

+------------------+
| RTC 每秒更新     |
+--------+---------+|v
+-------------------------+
| RTC_IRQn 中断触发      |
+-------------------------+|v
+-------------------------+
| HAL_RTCEx_RTCIRQHandler |
+-------------------------+|v
+-----------------------------+
| HAL_RTCEx_RTCEventCallback |
| (打印函数)           |
+-----------------------------+

完整代码（中断的方式获取时间）

📄 stm32f1xx_it.c

/* USER CODE BEGIN Header */
/********************************************************************************* @file    stm32f1xx_it.c* @brief   Interrupt Service Routines.******************************************************************************* @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 "stm32f1xx_it.h"
/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include "usart.h"
#include "iwdg.h"
#include "rtc.h"
/* USER CODE END Includes *//* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN TD *//* USER CODE END TD *//* 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 -----------------------------------------------*/
/* USER CODE BEGIN PFP *//* USER CODE END PFP *//* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 *//* USER CODE END 0 *//* External variables --------------------------------------------------------*/
extern RTC_HandleTypeDef hrtc;
extern TIM_HandleTypeDef htim3;
extern UART_HandleTypeDef huart1;
/* USER CODE BEGIN EV *//* USER CODE END EV *//******************************************************************************/
/*           Cortex-M3 Processor Interruption and Exception Handlers          */
/******************************************************************************/
/*** @brief This function handles Non maskable interrupt.*/
void NMI_Handler(void)
{/* USER CODE BEGIN NonMaskableInt_IRQn 0 *//* USER CODE END NonMaskableInt_IRQn 0 *//* USER CODE BEGIN NonMaskableInt_IRQn 1 */while (1){}/* USER CODE END NonMaskableInt_IRQn 1 */
}/*** @brief This function handles Hard fault interrupt.*/
void HardFault_Handler(void)
{/* USER CODE BEGIN HardFault_IRQn 0 *//* USER CODE END HardFault_IRQn 0 */while (1){/* USER CODE BEGIN W1_HardFault_IRQn 0 *//* USER CODE END W1_HardFault_IRQn 0 */}
}/*** @brief This function handles Memory management fault.*/
void MemManage_Handler(void)
{/* USER CODE BEGIN MemoryManagement_IRQn 0 *//* USER CODE END MemoryManagement_IRQn 0 */while (1){/* USER CODE BEGIN W1_MemoryManagement_IRQn 0 *//* USER CODE END W1_MemoryManagement_IRQn 0 */}
}/*** @brief This function handles Prefetch fault, memory access fault.*/
void BusFault_Handler(void)
{/* USER CODE BEGIN BusFault_IRQn 0 *//* USER CODE END BusFault_IRQn 0 */while (1){/* USER CODE BEGIN W1_BusFault_IRQn 0 *//* USER CODE END W1_BusFault_IRQn 0 */}
}/*** @brief This function handles Undefined instruction or illegal state.*/
void UsageFault_Handler(void)
{/* USER CODE BEGIN UsageFault_IRQn 0 *//* USER CODE END UsageFault_IRQn 0 */while (1){/* USER CODE BEGIN W1_UsageFault_IRQn 0 *//* USER CODE END W1_UsageFault_IRQn 0 */}
}/*** @brief This function handles System service call via SWI instruction.*/
void SVC_Handler(void)
{/* USER CODE BEGIN SVCall_IRQn 0 *//* USER CODE END SVCall_IRQn 0 *//* USER CODE BEGIN SVCall_IRQn 1 *//* USER CODE END SVCall_IRQn 1 */
}/*** @brief This function handles Debug monitor.*/
void DebugMon_Handler(void)
{/* USER CODE BEGIN DebugMonitor_IRQn 0 *//* USER CODE END DebugMonitor_IRQn 0 *//* USER CODE BEGIN DebugMonitor_IRQn 1 *//* USER CODE END DebugMonitor_IRQn 1 */
}/*** @brief This function handles Pendable request for system service.*/
void PendSV_Handler(void)
{/* USER CODE BEGIN PendSV_IRQn 0 *//* USER CODE END PendSV_IRQn 0 *//* USER CODE BEGIN PendSV_IRQn 1 *//* USER CODE END PendSV_IRQn 1 */
}/*** @brief This function handles System tick timer.*/
void SysTick_Handler(void)
{/* USER CODE BEGIN SysTick_IRQn 0 *//* USER CODE END SysTick_IRQn 0 */HAL_IncTick();/* USER CODE BEGIN SysTick_IRQn 1 *//* USER CODE END SysTick_IRQn 1 */
}/******************************************************************************/
/* STM32F1xx Peripheral Interrupt Handlers                                    */
/* Add here the Interrupt Handlers for the used peripherals.                  */
/* For the available peripheral interrupt handler names,                      */
/* please refer to the startup file (startup_stm32f1xx.s).                    */
/******************************************************************************//*** @brief This function handles RTC global interrupt.*/
void RTC_IRQHandler(void)
{/* USER CODE BEGIN RTC_IRQn 0 *//* USER CODE END RTC_IRQn 0 */HAL_RTCEx_RTCIRQHandler(&hrtc);/* USER CODE BEGIN RTC_IRQn 1 *//* USER CODE END RTC_IRQn 1 */
}/*** @brief This function handles EXTI line0 interrupt.*/
void EXTI0_IRQHandler(void)
{/* USER CODE BEGIN EXTI0_IRQn 0 *//* USER CODE END EXTI0_IRQn 0 */HAL_GPIO_EXTI_IRQHandler(PA0_Key_Pin);/* USER CODE BEGIN EXTI0_IRQn 1 *//* USER CODE END EXTI0_IRQn 1 */
}/*** @brief This function handles TIM3 global interrupt.*/
void TIM3_IRQHandler(void)
{/* USER CODE BEGIN TIM3_IRQn 0 *//* USER CODE END TIM3_IRQn 0 */HAL_TIM_IRQHandler(&htim3);/* USER CODE BEGIN TIM3_IRQn 1 *//* USER CODE END TIM3_IRQn 1 */
}/*** @brief This function handles USART1 global interrupt.*/
void USART1_IRQHandler(void)
{/* USER CODE BEGIN USART1_IRQn 0 *//* USER CODE END USART1_IRQn 0 */HAL_UART_IRQHandler(&huart1);/* USER CODE BEGIN USART1_IRQn 1 *//* USER CODE END USART1_IRQn 1 */
}/* USER CODE BEGIN 1 */void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin)
{if(GPIO_Pin == PA0_Key_Pin){if( HAL_GPIO_ReadPin(PA0_Key_GPIO_Port, PA0_Key_Pin) == GPIO_PIN_RESET){HAL_GPIO_TogglePin(GPIOC, LED_G_Pin);	//红灯的状态翻转
//			HAL_IWDG_Refresh(&hiwdg);		//进行喂狗
//			printf("Iwdg Count = %d \r\n", Count++);}}
}void HAL_UARTEx_RxEventCallback(UART_HandleTypeDef *huart, uint16_t Size)
{U1RxLen = Size;HAL_UARTEx_ReceiveToIdle_IT(&huart1, U1RxData, U1RxDataSize);	//启动串口空闲中断的接收U1RxFlag = 1;
}//TIM的中断回调函数 控制LED灯的闪烁
void HAL_TIM_PeriodElapsedCallback(TIM_HandleTypeDef *htim)
{
//	static uint32_t Count = 0;if(htim->Instance == TIM3)	//判断产生中断的哪一个中断回调函数{HAL_GPIO_TogglePin(LED_G_GPIO_Port, LED_G_Pin);	//绿灯的状态翻转HAL_IWDG_Refresh(&hiwdg);		//进行喂狗
//		printf("Iwdg Count = %d \r\n", Count++);}
}RTC_TimeTypeDef sTime;
RTC_DateTypeDef sDate;void HAL_RTCEx_RTCEventCallback(RTC_HandleTypeDef *hrtc)
{HAL_RTC_GetTime(hrtc, &sTime, RTC_FORMAT_BCD);HAL_RTC_GetDate(hrtc, &sDate, RTC_FORMAT_BCD);printf("TimeDate -> %d:%d:%d[%d] | %d:%d:%d	\r\n", sDate.Year,sDate.Month,sDate.Date,sDate.WeekDay,sTime.Hours,sTime.Minutes,sTime.Seconds);HAL_Delay(100);
}/* USER CODE END 1 */

📄 main.c

/* 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 "iwdg.h"
#include "rtc.h"
#include "tim.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 */
uint8_t U1SendData[] = {"hello world!"};
/* 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 *//* USER CODE END 0 *//*** @brief  The application entry point.* @retval int*/
int main(void)
{/* USER CODE BEGIN 1 */uint16_t pwmVal = 0;	//占空比/* 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();MX_IWDG_Init();MX_TIM3_Init();MX_RTC_Init();/* USER CODE BEGIN 2 */HAL_UARTEx_ReceiveToIdle_IT(&huart1, U1RxData, U1RxDataSize);	//使能空闲中断HAL_TIM_Base_Start_IT(&htim3);// 启动定时器HAL_TIM_PWM_Start(&htim3, TIM_CHANNEL_3);	//PWM初始化完毕之后，找到对应PWM的启动函数__HAL_RTC_SECOND_ENABLE_IT(&hrtc, RTC_IT_SEC);	//开启秒更新中断/* USER CODE END 2 *//* Infinite loop *//* USER CODE BEGIN WHILE */HAL_UART_Transmit(&huart1, U1SendData, sizeof(U1SendData), 0xff);	//启动串口空闲中断的发送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 RCC Oscillators according to the specified parameters* in the RCC_OscInitTypeDef structure.*/RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSI|RCC_OSCILLATORTYPE_HSE;RCC_OscInitStruct.HSEState = RCC_HSE_ON;RCC_OscInitStruct.HSEPredivValue = RCC_HSE_PREDIV_DIV1;RCC_OscInitStruct.HSIState = RCC_HSI_ON;RCC_OscInitStruct.LSIState = RCC_LSI_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();}PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_RTC;PeriphClkInit.RTCClockSelection = RCC_RTCCLKSOURCE_LSI;if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != 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 */

🧩 代码中的核心细节说明

__HAL_RTC_SECOND_ENABLE_IT() 说明

这个宏开启了 秒中断（SECIE）：

#define __HAL_RTC_SECOND_ENABLE_IT(__HANDLE__, __INTERRUPT__) \((__HANDLE__)->Instance->CRH |= (__INTERRUPT__))

配合：

#define RTC_IT_SEC ((uint32_t)RTC_CRH_SECIE)

它控制的是 RTC->CRH.SECIE 位，每秒触发一次 SECF 标志位，由 HAL 库内部清除。

HAL_RTCEx_RTCEventCallback() 是 HAL 提供的专用 RTC 秒中断回调函数：

void HAL_RTCEx_RTCEventCallback(RTC_HandleTypeDef *hrtc)
{// 每秒触发
}

它在 HAL_RTCEx_RTCIRQHandler() 中被调用：

if(__HAL_RTC_GET_IT(hrtc, RTC_IT_SEC) != RESET)
{__HAL_RTC_CLEAR_FLAG(hrtc, RTC_FLAG_SEC);HAL_RTCEx_RTCEventCallback(hrtc);
}

打印时钟：

HAL_RTC_GetTime(hrtc, &sTime, RTC_FORMAT_BCD);
HAL_RTC_GetDate(hrtc, &sDate, RTC_FORMAT_BCD);
printf("TimeDate -> %d:%d:%d[%d] | %d:%d:%d\r\n",sDate.Year, sDate.Month, sDate.Date, sDate.WeekDay,sTime.Hours, sTime.Minutes, sTime.Seconds);

每秒中断触发后，会打印一次当前时间，非常适合作为 RTC 秒事件验证。

另外，代码中可以去除 HAL_Delay(100)：这是因为在中断中使用 HAL_Delay() 不太安全，可能引发系统异常或丢中断。也可以替代为：

// 替代 HAL_Delay(100) 或者不加延时，使用定时器节奏控制打印频率。
for (volatile uint32_t i = 0; i < 100000; ++i);

还有，使用 RTC_FORMAT_BIN 更直观，这是因为BCD 格式读取后要自己解码，而使用 BIN 格式更便于直接打印和逻辑判断。

HAL_RTC_GetTime(hrtc, &sTime, RTC_FORMAT_BIN);
HAL_RTC_GetDate(hrtc, &sDate, RTC_FORMAT_BIN);

最后，RTC 时钟源也可以用 LSE（32.768kHz），目前这里使用的是：

PeriphClkInit.RTCClockSelection = RCC_RTCCLKSOURCE_LSI;

LSI 精度较低（±10%，温漂大），建议若有外部 32.768kHz 晶振，则改为：

PeriphClkInit.RTCClockSelection = RCC_RTCCLKSOURCE_LSE;

打印中也可以添加LED闪烁：

HAL_GPIO_TogglePin(GPIOC, GPIO_PIN_13); // 每秒闪烁一次LED

串口输出验证：（使用串口工具（如 SSCOM、PuTTY）查看打印内容是否每秒刷新。如图所示，是我打印出来的时钟：）

在这里插入图片描述

以上。这便是 STM32 HAL库 + RTC 每秒中断功能 的实现。

以上，欢迎有从事同行业的电子信息工程、互联网通信、嵌入式开发的朋友共同探讨与提问，我可以提供实战演示或模板库。希望内容能够对你产生帮助！