NUCLEO-L053R8：低功耗STOP模式，RTC唤醒（例程分享）

基于ST官方NUCLEO-L053R8开发板

代码下载：见附件

Stop mode with RTC：1uA VDD=3.0V

/**
* @brief  Main program
* @param  None
* @retval None
*/
int main(void)
{
  /* STM32L0xx HAL library initialization:
       - Configure the Flash prefetch, Flash preread and Buffer caches
       - Systick timer is configured by default as source of time base, but user 
             can eventually implement his proper time base source (a general purpose 
             timer for example or other time source), keeping in mind that Time base 
             duration should be kept 1ms since PPP_TIMEOUT_VALUEs are defined and 
             handled in milliseconds basis.
       - Low Level Initialization
     */
  HAL_Init();
  
  /* Configure LED2 to handle error handler */
  BSP_LED_Init(LED2);

  /* Configure the system clock @ 32 Mhz */
  SystemClock_Config();

  /* Configure the system Power */
  SystemPower_Config();

  while (1)
  {
    /* Insert 3 seconds delay */
    BSP_LED_Init(LED2); //LED初始化 
HAL_GPIO_WritePin(GPIOA, GPIO_PIN_5, GPIO_PIN_SET); //点亮LED,延时3S，再灭LED
HAL_Delay(3000);

HAL_GPIO_WritePin(GPIOA, GPIO_PIN_5, GPIO_PIN_RESET);
HAL_Delay(3000);
SystemPowerNORTC_Config(); //关闭所有IO和时钟，不关闭RTC

    /* Disable Wakeup Counter */
    HAL_RTCEx_DeactivateWakeUpTimer(&RTCHandle);

    /*## Setting the Wake up time ############################################*/
    /*  RTC Wakeup Interrupt Generation:
        Wakeup Time Base = (RTC_WAKEUPCLOCK_RTCCLK_DIV /(LSE or LSI))
        Wakeup Time = Wakeup Time Base * WakeUpCounter 
                    = (RTC_WAKEUPCLOCK_RTCCLK_DIV /(LSE or LSI)) * WakeUpCounter
        ==> WakeUpCounter = Wakeup Time / Wakeup Time Base

        To configure the wake up timer to 4s the WakeUpCounter is set to 0x1FFF:
          RTC_WAKEUPCLOCK_RTCCLK_DIV = RTCCLK_Div16 = 16 
          Wakeup Time Base = 16 /(~39.000KHz) = ~0,410 ms
          Wakeup Time = ~4s = 0,410ms  * WakeUpCounter
          ==> WakeUpCounter = ~4s/0,410ms = 9750 = 0x2616 */
    HAL_RTCEx_SetWakeUpTimer_IT(&RTCHandle, 0x2616, RTC_WAKEUPCLOCK_RTCCLK_DIV16);

    /* Enter Stop Mode */
    HAL_PWR_EnterSTOPMode(PWR_LOWPOWERREGULATOR_ON, PWR_STOPENTRY_WFI);

    /* Configures system clock after wake-up from STOP: enable HSI, PLL and select
    PLL as system clock source (HSI and PLL are disabled automatically in STOP mode) */
    SystemClockConfig_STOP();
  }
}