STM32L152 RTC 日曆和定時中斷使用

STM32L152 RTC 日曆和自動喚醒功能配置

1、開發平臺：

STM32L1-Discovery Keil 4

2、RTC Calendar和wake up

• STM32L152RC 帶有一個硬件的實時時鐘模塊(RTC),可爲用戶提供日曆功能，RTC也可以提供一個自動定時的功能，相當於是一個睡眠定時器，下面就看看該如何配置日曆和定時：

 void SYS_RTCInit(void)
{
    static NVIC_InitTypeDef  NVIC_InitStructure;
    static EXTI_InitTypeDef  EXTI_InitStructure;
    static RTC_InitTypeDef RTC_InitStructure;
    static RTC_TimeTypeDef RTC_TimeStructure;
    static uint32_t AsynchPrediv = 0, SynchPrediv = 0;

    RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR, ENABLE);

    /*!< Allow access to RTC */
    PWR_RTCAccessCmd(ENABLE);

    /*!< 使能外部低速時鐘 */
    RCC_LSEConfig(RCC_LSE_ON);

    /*!< 等待外部低速時鐘就緒 */
    while (RCC_GetFlagStatus(RCC_FLAG_LSERDY) == RESET)
    {}

    /*!< 配置RTC時鐘來源 */
    RCC_RTCCLKConfig(RCC_RTCCLKSource_LSE);

    /*!< 使能RTC時鐘 */
    RCC_RTCCLKCmd(ENABLE);

    /*!< Wait for RTC APB registers synchronisation */
    RTC_WaitForSynchro();

    //配置日曆
    /* 配置RTC數據寄存器以及時鐘分頻 */
    SynchPrediv = 0xFF;
    AsynchPrediv = 0x7F;//分頻爲1Hz
    RTC_InitStructure.RTC_AsynchPrediv = AsynchPrediv;
    RTC_InitStructure.RTC_SynchPrediv = SynchPrediv;
    RTC_InitStructure.RTC_HourFormat = RTC_HourFormat_24;//24小時制
    /* 檢查RTC初始化 */
    if (RTC_Init(&RTC_InitStructure) == ERROR)
    {
        printf("\n\r        /!\\***** RTC Prescaler Config failed ********/!\\ \n\r");
    }
    //配置時間 9點15分01秒
    RTC_TimeStructure.RTC_H12     = RTC_H12_AM;
    RTC_TimeStructure.RTC_Hours = 0x09;
    RTC_TimeStructure.RTC_Minutes = 0x15;
    RTC_TimeStructure.RTC_Seconds = 0x01;
    RTC_SetTime(RTC_Format_BCD, &RTC_TimeStructure);

    //配置自動定時功能
    /* 中斷配置 *******************************************************/
    EXTI_ClearITPendingBit(EXTI_Line20);
    EXTI_InitStructure.EXTI_Line = EXTI_Line20;
    EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
    EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising;
    EXTI_InitStructure.EXTI_LineCmd = ENABLE;
    EXTI_Init(&EXTI_InitStructure);

    /*使能 RTC Wakeup Interrupt */
    NVIC_InitStructure.NVIC_IRQChannel = RTC_WKUP_IRQn;
    NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
    NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
    NVIC_Init(&NVIC_InitStructure);

    /* RTC 喚醒中端配置: Clock Source: RTCDiv_16, Wakeup Time Base: 4s */
    RTC_WakeUpClockConfig(RTC_WakeUpClock_RTCCLK_Div16);
    RTC_SetWakeUpCounter(0x1FFF);//0x1FFF = 8191; 4s = (8191+1)*(1/(32768/16))

    /* 使能 the Wakeup Interrupt */
    RTC_ITConfig(RTC_IT_WUT, ENABLE);  
}

• 使能了RTC的定時中斷，那麼就要編寫中斷服務子程序，如下：

void RTC_WKUP_IRQHandler(void)
{
  if(RTC_GetITStatus(RTC_IT_WUT) != RESET)
  {
    RTC_ClearITPendingBit(RTC_IT_WUT);
    EXTI_ClearITPendingBit(EXTI_Line20);
  } 
}