STM32L432 SLEEP MODE AND WAKE UP through RTC

[pradeepwagre]

I am developing a application for Battery based 4G GATEWAY so most of the time I want my micro-controller in sleep mode.I am using Standby Mode as I require least power consumption.The requirement I need is I want to wake micro-controller at specific time like 6am,12pm,6pm and 12 noon.Initially 6am time will be set and once alarm is raised,interrupt comes next alarm will be configured and again we go in sleep mode.Below is my configuration for RTC and Alarm.The interrupt works as required when I don't call Enter_Standby_Mode function.But when I call Enter_Standby_Mode and controller goes in sleep.It won't come out of Sleep when RTC time matches ALARM A time.Basically its interrupted is not getting generated.Where I am going wrong?can any one reply?

/* USER CODE BEGIN Header */
/**
  ******************************************************************************
  * @file           : main.c
  * @brief          : Main program body
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2024 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"

/* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
  RTC_TimeTypeDef sTime = {0};
  RTC_DateTypeDef sDate = {0};
  RTC_AlarmTypeDef sAlarm = {0};
/* USER CODE END Includes */

/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */

/* 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 ---------------------------------------------------------*/
RTC_HandleTypeDef hrtc;

/* USER CODE BEGIN PV */

/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_RTC_Init(void);
/* USER CODE BEGIN PFP */
void HAL_RTC_AlarmAEventCallback(RTC_HandleTypeDef *hrtc);
void Enter_Standby_Mode(void);
/* USER CODE END PFP */

/* Private user code ---------------------------------------------------------*/
/* USER CODE BEGIN 0 */
volatile uint8_t PwrDwnFlag = 1;
/* 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_RTC_Init();
  /* USER CODE BEGIN 2 */
  /*LL_GPIO_SetOutputPin(Q_RESET_GPIO_Port, Q_RESET_Pin);
  HAL_Delay(20);
  LL_GPIO_ResetOutputPin(Q_RESET_GPIO_Port, Q_RESET_Pin);
  HAL_Delay(150);
  LL_GPIO_SetOutputPin(Q_RESET_GPIO_Port, Q_RESET_Pin);
  HAL_Delay(20);

  LL_GPIO_SetOutputPin(Q_PWRKEY_GPIO_Port, Q_PWRKEY_Pin);
  HAL_Delay(20);
  LL_GPIO_ResetOutputPin(Q_PWRKEY_GPIO_Port, Q_PWRKEY_Pin);
  HAL_Delay(2000);
  LL_GPIO_SetOutputPin(Q_PWRKEY_GPIO_Port, Q_PWRKEY_Pin);
  HAL_Delay(20);*/
  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  while (1)
  {
    /* USER CODE END WHILE */

    /* USER CODE BEGIN 3 */
      // MCU will keep entering sleep mode unless a wakeup event occurs
	  //LL_GPIO_ResetOutputPin(GPIOB, LL_GPIO_PIN_3);
	  //HAL_Delay(1000);
	  //LL_GPIO_SetOutputPin(GPIOB, LL_GPIO_PIN_3);
	  //HAL_Delay(1000);

	  if(PwrDwnFlag  == 1)
	  {
		  PwrDwnFlag = 0;

		  Enter_Standby_Mode();
	  }



  }
  /* USER CODE END 3 */
}

/**
  * @brief System Clock Configuration
  * @retval None
  */
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};

  /** Configure the main internal regulator output voltage
  */
  if (HAL_PWREx_ControlVoltageScaling(PWR_REGULATOR_VOLTAGE_SCALE1) != HAL_OK)
  {
    Error_Handler();
  }

  /** Configure LSE Drive Capability
  */
  HAL_PWR_EnableBkUpAccess();
  __HAL_RCC_LSEDRIVE_CONFIG(RCC_LSEDRIVE_LOW);

  /** Initializes the RCC Oscillators according to the specified parameters
  * in the RCC_OscInitTypeDef structure.
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSI|RCC_OSCILLATORTYPE_LSE
                              |RCC_OSCILLATORTYPE_MSI;
  RCC_OscInitStruct.LSEState = RCC_LSE_ON;
  RCC_OscInitStruct.LSIState = RCC_LSI_ON;
  RCC_OscInitStruct.MSIState = RCC_MSI_ON;
  RCC_OscInitStruct.MSICalibrationValue = 0;
  RCC_OscInitStruct.MSIClockRange = RCC_MSIRANGE_6;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_MSI;
  RCC_OscInitStruct.PLL.PLLM = 1;
  RCC_OscInitStruct.PLL.PLLN = 40;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV7;
  RCC_OscInitStruct.PLL.PLLQ = RCC_PLLQ_DIV2;
  RCC_OscInitStruct.PLL.PLLR = RCC_PLLR_DIV2;
  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_DIV1;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_4) != HAL_OK)
  {
    Error_Handler();
  }

  /** Enable MSI Auto calibration
  */
  HAL_RCCEx_EnableMSIPLLMode();
}

/**
  * @brief RTC Initialization Function
  *  None
  * @retval None
  */
static void MX_RTC_Init(void)
{

  /* USER CODE BEGIN RTC_Init 0 */

  /* USER CODE END RTC_Init 0 */



  /* USER CODE BEGIN RTC_Init 1 */

  /* USER CODE END RTC_Init 1 */

  /** Initialize RTC Only
  */
  hrtc.Instance = RTC;
  hrtc.Init.HourFormat = RTC_HOURFORMAT_24;
  hrtc.Init.AsynchPrediv = 127;
  hrtc.Init.SynchPrediv = 255;
  hrtc.Init.OutPut = RTC_OUTPUT_DISABLE;
  hrtc.Init.OutPutRemap = RTC_OUTPUT_REMAP_NONE;
  hrtc.Init.OutPutPolarity = RTC_OUTPUT_POLARITY_HIGH;
  hrtc.Init.OutPutType = RTC_OUTPUT_TYPE_OPENDRAIN;
  if (HAL_RTC_Init(&hrtc) != HAL_OK)
  {
    Error_Handler();
  }

  /* USER CODE BEGIN Check_RTC_BKUP */

  /* USER CODE END Check_RTC_BKUP */

  /** Initialize RTC and set the Time and Date
  */
  sTime.Hours = 8;
  sTime.Minutes = 52;
  sTime.Seconds = 0;
  sTime.DayLightSaving = RTC_DAYLIGHTSAVING_NONE;
  sTime.StoreOperation = RTC_STOREOPERATION_RESET;
  if (HAL_RTC_SetTime(&hrtc, &sTime, RTC_FORMAT_BIN) != HAL_OK)
  {
    Error_Handler();
  }
  sDate.WeekDay = RTC_WEEKDAY_THURSDAY;
  sDate.Month = RTC_MONTH_SEPTEMBER;
  sDate.Date = 19;
  sDate.Year = 24;

  if (HAL_RTC_SetDate(&hrtc, &sDate, RTC_FORMAT_BIN) != HAL_OK)
  {
    Error_Handler();
  }

  /** Enable the Alarm A
  */
  sAlarm.AlarmTime.Hours = 8;
  sAlarm.AlarmTime.Minutes = 53;
  sAlarm.AlarmTime.Seconds = 0;
  sAlarm.AlarmTime.SubSeconds = 0;
  sAlarm.AlarmTime.DayLightSaving = RTC_DAYLIGHTSAVING_NONE;
  sAlarm.AlarmTime.StoreOperation = RTC_STOREOPERATION_RESET;
  sAlarm.AlarmMask = RTC_ALARMMASK_DATEWEEKDAY;
  sAlarm.AlarmSubSecondMask = RTC_ALARMSUBSECONDMASK_ALL;
  sAlarm.AlarmDateWeekDaySel = RTC_ALARMDATEWEEKDAYSEL_DATE;
  sAlarm.AlarmDateWeekDay = 1;
  sAlarm.Alarm = RTC_ALARM_A;
  if (HAL_RTC_SetAlarm_IT(&hrtc, &sAlarm, RTC_FORMAT_BIN) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN RTC_Init 2 */

  /* USER CODE END RTC_Init 2 */

}

/**
  * @brief GPIO Initialization Function
  *  None
  * @retval None
  */
static void MX_GPIO_Init(void)
{
  LL_GPIO_InitTypeDef GPIO_InitStruct = {0};
/* USER CODE BEGIN MX_GPIO_Init_1 */
/* USER CODE END MX_GPIO_Init_1 */

  /* GPIO Ports Clock Enable */
  LL_AHB2_GRP1_EnableClock(LL_AHB2_GRP1_PERIPH_GPIOC);
  LL_AHB2_GRP1_EnableClock(LL_AHB2_GRP1_PERIPH_GPIOA);
  LL_AHB2_GRP1_EnableClock(LL_AHB2_GRP1_PERIPH_GPIOB);

  /**/
  LL_GPIO_ResetOutputPin(LED_GPIO_Port, LED_Pin);

  /**/
  GPIO_InitStruct.Pin = LED_Pin;
  GPIO_InitStruct.Mode = LL_GPIO_MODE_OUTPUT;
  GPIO_InitStruct.Speed = LL_GPIO_SPEED_FREQ_LOW;
  GPIO_InitStruct.OutputType = LL_GPIO_OUTPUT_PUSHPULL;
  GPIO_InitStruct.Pull = LL_GPIO_PULL_NO;
  LL_GPIO_Init(LED_GPIO_Port, &GPIO_InitStruct);

/* USER CODE BEGIN MX_GPIO_Init_2 */
  LL_GPIO_ResetOutputPin(GPIOB, LED_Pin);
/* USER CODE END MX_GPIO_Init_2 */
}

/* USER CODE BEGIN 4 */
void Enter_Standby_Mode(void)
{
    // Clear the wakeup flags
    __HAL_PWR_CLEAR_FLAG(PWR_FLAG_WU);

    // Disable SysTick before going to sleep
    HAL_SuspendTick();

    // Enable the RTC Alarm wakeup source
    HAL_PWR_EnableWakeUpPin(PWR_WAKEUP_PIN1);

    // Enter Standby mode (will wake up on RTC Alarm)
    HAL_PWR_EnterSTANDBYMode();
}

void HAL_RTC_AlarmAEventCallback(RTC_HandleTypeDef *hrtc)
{
  HAL_RTC_GetAlarm(hrtc,&sAlarm,RTC_ALARM_A,FORMAT_BIN);
  HAL_RTC_GetTime(hrtc,&sTime,FORMAT_BIN);
  HAL_RTC_GetDate(hrtc,&sDate,FORMAT_BIN);
  /*if(sAlarm.AlarmTime.Seconds>59)
  {
    sAlarm.AlarmTime.Seconds=0;
  }
  else
  {
    sAlarm.AlarmTime.Seconds=sAlarm.AlarmTime.Seconds+1;
  }
  while(HAL_RTC_SetAlarm_IT(hrtc, &sAlarm, FORMAT_BIN)!=HAL_OK){}*/
  // Once the MCU wakes up, SysTick should be resumed (re-enabled)
  //HAL_ResumeTick();
  LL_GPIO_TogglePin(GPIOB, LED_Pin);
  PwrDwnFlag = 1;
}
/* 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.
  *   file: pointer to the source file name
  *   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 */