/* USER CODE BEGIN Header */
/**
  ******************************************************************************

  * @file    PWR/PWR_STANDBY_RTC/Src/main.c
  * @author  MCD Application Team
  * @brief   This sample code shows how to use STM32WLxx PWR HAL API to enter
  *          and exit the Standby mode using RTC.
  ******************************************************************************
  * @attention
  *
  * Copyright (c) 2020 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 */

/* USER CODE END Includes */

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

/* USER CODE END PTD */

/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
#define LED_TOGGLE_DELAY         100UL
/* USER CODE END PD */

/* Private macro -------------------------------------------------------------*/
/* USER CODE BEGIN PM */

/* USER CODE END PM */

/* Private variables ---------------------------------------------------------*/
RTC_HandleTypeDef hrtc;

/* USER CODE BEGIN PV */
static __IO uint32_t TimingDelay;
/* USER CODE END PV */

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_RTC_Init(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 */

  /* STM32WLxx HAL library initialization:
       - Configure the Flash prefetch
       - 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.
       - Set NVIC Group Priority to 4
       - Low Level Initialization
     */
  /* 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 */
  /* Configure LED2, LED3 */
  BSP_LED_Init(LED2);
  BSP_LED_Init(LED3);
  /* USER CODE END SysInit */

  /* Initialize all configured peripherals */
  /* USER CODE BEGIN 2 */

  /* Check and handle if the system was resumed from StandBy mode */
  if(__HAL_PWR_GET_FLAG(PWR_FLAG_SB) == RESET)
  {
    MX_RTC_Init();
  }
  else
  {
    /* Clear Standby flag */
    __HAL_PWR_CLEAR_FLAG(PWR_FLAG_SB);

    /* Enable access to RTC domain for following wake-up source configuration */
    HAL_PWR_EnableBkUpAccess();
    __HAL_RCC_RTCAPB_CLK_ENABLE();    
  }
  
  /* Insert 5 seconds delay */
  HAL_Delay(5000);
  
  /* The Following Wakeup sequence is highly recommended prior to each Standby mode entry
    mainly  when using more than one wakeup source this is to not miss any wakeup event.
    - Disable all used wakeup sources,
    - Clear all related wakeup flags, 
    - Re-enable all used wakeup sources,
    - Enter the Standby mode.
  */
  /* Disable all used wakeup sources*/
  HAL_RTCEx_DeactivateWakeUpTimer(&hrtc);
  
  /* Clear all related wakeup flags */
  __HAL_PWR_CLEAR_FLAG(PWR_FLAG_WU);
  
  /* Re-enable wakeup source */
  /* ## Setting the Wake up time ############################################*/
  /* RTC Wakeup Interrupt Generation: 
    the wake-up counter is set to its maximum value to yield the longest
    stand-by time to let the current reach its lowest operating point.
    The maximum value is 0xFFFF, corresponding to about 33 sec. when 
    RTC_WAKEUPCLOCK_RTCCLK_DIV = RTCCLK_Div16 = 16

    Wakeup Time Base = (RTC_WAKEUPCLOCK_RTCCLK_DIV /(LSI))
    Wakeup Time = Wakeup Time Base * WakeUpCounter 
      = (RTC_WAKEUPCLOCK_RTCCLK_DIV /(LSI)) * WakeUpCounter
      ==> WakeUpCounter = Wakeup Time / Wakeup Time Base
  
    To configure the wake up timer to 33s the WakeUpCounter is set to 0xFFFF:
    Wakeup Time Base = 16 /(~32 kHz RC) = ~0.5 ms
    Wakeup Time = 0.5 ms  * WakeUpCounter
    Therefore, with wake-up counter =  0xFFFF  = 65,535 
       Wakeup Time =  0.5 ms *  65,535 = ~ 33 sec. */
  HAL_RTCEx_SetWakeUpTimer_IT(&hrtc, 0xFFFF, RTC_WAKEUPCLOCK_RTCCLK_DIV16, 0);
  
  /* Enter the Standby mode */
  HAL_PWR_EnterSTANDBYMode();
  
  /* Program should never reach this point (program restart when exiting from standby mode) */
  Error_Handler(); 
  /* USER CODE END 2 */

  /* Infinite loop */
  /* USER CODE BEGIN WHILE */
  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};

  /** Configure the main internal regulator output voltage
  */
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);

  /** Initializes the CPU, AHB and APB buses clocks
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_LSI|RCC_OSCILLATORTYPE_MSI;
  RCC_OscInitStruct.MSIState = RCC_MSI_ON;
  RCC_OscInitStruct.MSICalibrationValue = RCC_MSICALIBRATION_DEFAULT;
  RCC_OscInitStruct.MSIClockRange = RCC_MSIRANGE_8;
  RCC_OscInitStruct.LSIDiv = RCC_LSI_DIV1;
  RCC_OscInitStruct.LSIState = RCC_LSI_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_MSI;
  RCC_OscInitStruct.PLL.PLLM = RCC_PLLM_DIV4;
  RCC_OscInitStruct.PLL.PLLN = 24;
  RCC_OscInitStruct.PLL.PLLP = RCC_PLLP_DIV2;
  RCC_OscInitStruct.PLL.PLLR = RCC_PLLR_DIV2;
  RCC_OscInitStruct.PLL.PLLQ = RCC_PLLQ_DIV2;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }
  /** Configure the SYSCLKSource, HCLK, PCLK1 and PCLK2 clocks dividers
  */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK3|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;
  RCC_ClkInitStruct.AHBCLK3Divider = RCC_SYSCLK_DIV1;

  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_2) != HAL_OK)
  {
    Error_Handler();
  }
}

/**
  * @brief RTC Initialization Function
  * @param 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 = RTC_ASYNCH_PREDIV;
  hrtc.Init.SynchPrediv = RTC_SYNCH_PREDIV;
  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;
  hrtc.Init.OutPutPullUp = RTC_OUTPUT_PULLUP_NONE;
  hrtc.Init.BinMode = RTC_BINARY_NONE;
  if (HAL_RTC_Init(&hrtc) != HAL_OK)
  {
    Error_Handler();
  }
  /* USER CODE BEGIN RTC_Init 2 */

  /* USER CODE END RTC_Init 2 */

}

/* USER CODE BEGIN 4 */


/**
  * @brief SYSTICK callback
  * @param None
  * @retval None
  */
void HAL_SYSTICK_Callback(void)
{

  if (TimingDelay != 0)
  {
    TimingDelay--;
  }
  else
  {
    /* Toggle LED2 */
    BSP_LED_Toggle(LED2);
    TimingDelay = LED_TOGGLE_DELAY;
  }
}

/* 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 */
  /* Turn on the LED3 */
  BSP_LED_On(LED3);
 /* User can add his own implementation to report the HAL error return state */
  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) */
  /* Infinite loop */
  while (1)
  {
  }
  /* USER CODE END 6 */
}
#endif /* USE_FULL_ASSERT */
