🕒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:
RTC时钟秒更新中断流程:
🧾 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 |
handlebars
+------------------+
| 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
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
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):
c
#define __HAL_RTC_SECOND_ENABLE_IT(__HANDLE__, __INTERRUPT__) \
((__HANDLE__)->Instance->CRH |= (__INTERRUPT__))
配合:
c
#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:
c
void HAL_RTCEx_RTCEventCallback(RTC_HandleTypeDef *hrtc)
{
// 每秒触发
}
它在 HAL_RTCEx_RTCIRQHandler()
中被调用:
c
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:
c
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:
c
// 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。
c
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:
c
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:
c
PeriphClkInit.RTCClockSelection = RCC_RTCCLKSOURCE_LSE;
打印中也可以添加LED闪烁:
c
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:)

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!