In STM32f103c8t6 RTC Time not updated

[pushkarmondhe]

Hi all,I am working on stm32f103c8t6 controller.I am using LSI Clock of 40MHZ & external clock of 36MHZ.I am trying to read the clock after power off &n on by using the following code.Eventhough the 3.3v is detected on the pin,the clock is not getting updated during the power off.It is reading from the previous stored value in the backup register .please help me to resolve this issue

/ 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 /
#include <stdio.h>
#include <string.h>
/ 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;

UART_HandleTypeDef huart3;
char time[10];
char date[10];
RTC_TimeTypeDef RtcTime;
RTC_DateTypeDef RtcDate;

uint8_t CompareSeconds;
uint8_t CompareDate;

uint8_t Message[64];
uint8_t MessageLen;
uint8_t Messagexyz[64];
uint8_t MessageLenxyz;

/ USER CODE BEGIN PV /

void SetRTC(void);
void BackupDateToBR(void);

/ USER CODE END PV /

/* Private function prototypes -----------------------------------------------*/
void SystemClock_Config(void);
static void MX_GPIO_Init(void);
static void MX_RTC_Init(void);
static void MX_USART3_UART_Init(void);
/ USER CODE BEGIN PFP /
extern uint32_t CalculateDayNumber(uint8_t Date, uint8_t Month, uint8_t Year); // DD.MM.YY
extern void CalculateDateFromDayNumber(uint32_t DayNumber, uint8_t Date, uint8_t Month, uint8_t *Year);
/ USER CODE END PFP /

/* Private user code ---------------------------------------------------------*/
/ USER CODE BEGIN 0 /

/ USER CODE BEGIN 1 /
uint32_t CalculateDayNumber(uint8_t Date, uint8_t Month, uint8_t Year)
{
// Format:
// DD.MM.YY
uint32_t _Year = Year + 20;
Month = (Month + 9) % 12;
Year = Year - (Month / 10);
return ((365  Year) + (Year / 4) - (Year / 100) + (Year / 400) + (((Month  306) + 5) / 10) + (Date - 1));
}

void CalculateDateFromDayNumber(uint32_t DayNumber, uint8_t Date, uint8_t Month, uint8_t *Year)
{
uint32_t Date, Month, _Year;
_Year = ((10000 * DayNumber) + 14780) / 3652425;
int32_t ddd = DayNumber - ((365 * Year) + (Year / 4) - (Year / 100) + (Year / 400));
if (ddd < 0)
{
_Year -= 1;
ddd = DayNumber - ((365 * Year) + (Year / 4) - (Year / 100) + (Year / 400));
}
int32_t mi = ((100 * ddd) + 52) / 3060;
_Month = (mi + 2) % 12 + 1;
Year = Year + (mi + 2)/12;
_Date = ddd - ((mi * 306) + 5)/10 + 1;
*Date = _Date;
*Month = _Month;
*Year = _Year - 20;
}

/ 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();
  MX_USART3_UART_Init();
  / USER CODE BEGIN 2 /



  / USER CODE END 2 /

  / Infinite loop /
  / USER CODE BEGIN WHILE /
  HAL_GPIO_WritePin(GPIOA, GPIO_PIN_15, GPIO_PIN_SET);
  HAL_Delay(200);
  HAL_GPIO_WritePin(GPIOB, GPIO_PIN_13, GPIO_PIN_SET);
  HAL_Delay(200);
  HAL_GPIO_WritePin(GPIOA, GPIO_PIN_15, GPIO_PIN_RESET);
  HAL_Delay(2000);

  while (1)
  {
    / USER CODE END WHILE /
   HAL_RTC_GetTime(&hrtc, &RtcTime, RTC_FORMAT_BIN);
  HAL_RTC_GetDate(&hrtc, &RtcDate, RTC_FORMAT_BIN);
     HAL_UART_Transmit(&huart3, Messagexyz, MessageLenxyz, 100);

  if(RtcTime.Seconds != CompareSeconds)
  {
  MessageLen = sprintf((char*)Message, "Date: %02d.%02d.20%02d Time: %02d:%02d:%02d\n\r", RtcDate.Date, RtcDate.Month, RtcDate.Year, RtcTime.Hours, RtcTime.Minutes, RtcTime.Seconds);
  HAL_UART_Transmit(&huart3, Message, MessageLen, 100);
  CompareSeconds = RtcTime.Seconds;
  }
  if(RtcDate.Date != CompareDate)
  {
  BackupDateToBR();
  CompareDate = RtcDate.Date;
  }

  // if(GPIO_PIN_RESET == HAL_GPIO_ReadPin(TEST_GPIO_Port, TEST_Pin))
  // {
//  while(GPIO_PIN_RESET == HAL_GPIO_ReadPin(TEST_GPIO_Port, TEST_Pin))
//  {}
//  SetRTC();
  // }
    HAL_Delay(1000);
    / 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_HSI | RCC_OSCILLATORTYPE_LSI;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
  RCC_OscInitStruct.LSIState = RCC_LSI_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI_DIV2;
  RCC_OscInitStruct.PLL.PLLMUL = RCC_PLL_MUL2;
  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_0) != HAL_OK)
  {
    Error_Handler();
  }

  PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_RTC;
  PeriphClkInit.RTCClockSelection = RCC_RTCCLKSOURCE_LSI;
  if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK)
  {
    Error_Handler();
  }
}



void MX_RTC_Init(void)
{
  RTC_TimeTypeDef sTime = {0};
  RTC_DateTypeDef DateToUpdate = {0};

  /** Initialize RTC Only 
  */
  hrtc.Instance = RTC;
  hrtc.Init.AsynchPrediv = RTC_AUTO_1_SECOND;
  hrtc.Init.OutPut = RTC_OUTPUTSOURCE_ALARM;
  if (HAL_RTC_Init(&hrtc) != HAL_OK)
  {
    Error_Handler();
  }

  / USER CODE BEGIN Check_RTC_BKUP /

  RTC_DateTypeDef BackupDate;

  RtcDate.Date = (HAL_RTCEx_BKUPRead(&hrtc, RTC_BKP_DR2) >> 8);
  RtcDate.Month = HAL_RTCEx_BKUPRead(&hrtc, RTC_BKP_DR2);
  RtcDate.Year = (HAL_RTCEx_BKUPRead(&hrtc, RTC_BKP_DR3) >> 8);
  RtcDate.WeekDay = HAL_RTCEx_BKUPRead(&hrtc, RTC_BKP_DR3);

  MessageLenxyz = sprintf((char*)Messagexyz, "Backup Date Value: %d, Month: %d, Year: %d, Weekday: %d\n\r", RtcDate.Date, RtcDate.Month, RtcDate.Year, RtcDate.WeekDay);


  HAL_RTC_GetTime(&hrtc, &RtcTime, RTC_FORMAT_BIN); // There is also an internal date update based on HW RTC time elapsed!!
  HAL_RTC_GetDate(&hrtc, &BackupDate, RTC_FORMAT_BIN); // Days elapsed since MCU power down

  uint32_t BackupDateDays = CalculateDayNumber(BackupDate.Date, BackupDate.Month, BackupDate.Year);
  uint32_t RtcDateDays = CalculateDayNumber(RtcDate.Date, RtcDate.Month, RtcDate.Year);

      // MessageLenxyz = sprintf((char*)Messagexyz, "BackupDateDays : %d RtcDateDays: %d\n\r", BackupDateDays,RtcDateDays);
 

  RtcDateDays += (BackupDateDays - CalculateDayNumber(1, 1, 0));

  CalculateDateFromDayNumber(RtcDateDays, &RtcDate.Date, &RtcDate.Month, &RtcDate.Year);

  HAL_RTC_SetDate(&hrtc, &RtcDate, RTC_FORMAT_BIN);

  //
  // You have to do not let Init code to reinitialize Time and Date in RTC.
  // It's "a bug" in HAL widely described and complain on forums.
  // That causes every MCU restart the time and date will be same as you configured in CubeMX.
  // All you have to do is just return before init time/date in this user section.
  //
    return;
  / USER CODE END Check_RTC_BKUP /

  /** Initialize RTC and set the Time and Date 
  */
  sTime.Hours = 23;
  sTime.Minutes = 59;
  sTime.Seconds = 55;

  if (HAL_RTC_SetTime(&hrtc, &sTime, RTC_FORMAT_BIN) != HAL_OK)
  {
    Error_Handler();
  }
  DateToUpdate.WeekDay = RTC_WEEKDAY_SATURDAY;
  DateToUpdate.Month = RTC_MONTH_FEBRUARY;
  DateToUpdate.Date = 3;
  DateToUpdate.Year = 20;

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

}

/**
  * @brief USART3 Initialization Function
  * @PAram None
  * @retval None
  */
static void MX_USART3_UART_Init(void)
{
  / USER CODE BEGIN USART3_Init 0 /
  / USER CODE END USART3_Init 0 /

  / USER CODE BEGIN USART3_Init 1 /
  / USER CODE END USART3_Init 1 /

  huart3.Instance = USART3;
  huart3.Init.BaudRate = 115200;
  huart3.Init.WordLength = UART_WORDLENGTH_8B;
  huart3.Init.StopBits = UART_STOPBITS_1;
  huart3.Init.Parity = UART_PARITY_NONE;
  huart3.Init.Mode = UART_MODE_TX_RX;
  huart3.Init.HwFlowCtl = UART_HWCONTROL_NONE;
  huart3.Init.OverSampling = UART_OVERSAMPLING_16;
  if (HAL_UART_Init(&huart3) != HAL_OK)
  {
    Error_Handler();
  }
  / USER CODE BEGIN USART3_Init 2 /
  / USER CODE END USART3_Init 2 /
}

/**
  * @brief GPIO Initialization Function
  * @PAram None
  * @retval None
  */
static void MX_GPIO_Init(void)
{
  GPIO_InitTypeDef GPIO_InitStruct = {0};

  / GPIO Ports Clock Enable /
  __HAL_RCC_GPIOC_CLK_ENABLE();
  __HAL_RCC_GPIOD_CLK_ENABLE();
  __HAL_RCC_GPIOA_CLK_ENABLE();
  __HAL_RCC_GPIOB_CLK_ENABLE();

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(GPIOA, GPIO_PIN_15, GPIO_PIN_RESET);

  /*Configure GPIO pin Output Level */
  HAL_GPIO_WritePin(GPIOB, GPIO_PIN_13, GPIO_PIN_RESET);

  /*Configure GPIO pin : PA15 */
  GPIO_InitStruct.Pin = GPIO_PIN_15;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(GPIOA, &GPIO_InitStruct);

  /*Configure GPIO pin : PB13 */
  GPIO_InitStruct.Pin = GPIO_PIN_13;
  GPIO_InitStruct.Mode = GPIO_MODE_OUTPUT_PP;
  GPIO_InitStruct.Pull = GPIO_NOPULL;
  GPIO_InitStruct.Speed = GPIO_SPEED_FREQ_LOW;
  HAL_GPIO_Init(GPIOB, &GPIO_InitStruct);
}

/ USER CODE BEGIN 4 /
void BackupDateToBR(void)
{
HAL_RTCEx_BKUPWrite(&hrtc, RTC_BKP_DR2, ((RtcDate.Date << ‌‌ | (RtcDate.Month)));
HAL_RTCEx_BKUPWrite(&hrtc, RTC_BKP_DR3, ((RtcDate.Year << ‌‌ | (RtcDate.WeekDay)));
  
}

void SetRTC(void)
{
RTC_TimeTypeDef sTime = {0};
RTC_DateTypeDef DateToUpdate = {0};

/** Initialize RTC and set the Time and Date
*/
sTime.Hours = 23;
sTime.Minutes = 59;
sTime.Seconds = 56;

if (HAL_RTC_SetTime(&hrtc, &sTime, RTC_FORMAT_BIN) != HAL_OK)
{
  Error_Handler();
}

DateToUpdate.WeekDay = RTC_WEEKDAY_SATURDAY;
DateToUpdate.Month = RTC_MONTH_FEBRUARY;
DateToUpdate.Date = 3;
DateToUpdate.Year = 20;

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

BackupDateToBR();
}
/ USER CODE END 4 /

/**
  * @brief  This function is executed in case of error occurrence.
  * @retval None
  */
void Error_Handler(void)
{
  __disable_irq();
  while (1)
  {
  }
}

#ifdef  USE_FULL_ASSERT

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 /

[Techn]

Please use LSE for the RTC  configuration. Please send me the .ioc file