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2 min interrupt using RTC

Question asked by storm.blue on Sep 4, 2012
Latest reply on Sep 4, 2012 by fm
Hi all,
I am new to programming. I wanted some help regarding rtc coding. I am using stm32l1 discovery board(and IAR workbench), and want to generate interrupt after every 2 mins. I think using timers for this will be tricky. I tried one vague attempt using std periph examples, and obviously it din work.. I donno the format that i should give for 2 mins interrupt generation. 


void RTC_Config(void)
{

  RTC_InitTypeDef RTC_InitStructure;
  RTC_TimeTypeDef  RTC_TimeStruct;
 
  /* Enable the PWR clock */
  RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR, ENABLE);

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

  /* Reset RTC Domain */
  RCC_RTCResetCmd(ENABLE);
  RCC_RTCResetCmd(DISABLE);

  /* Enable the LSE OSC */
  RCC_LSEConfig(RCC_LSE_ON);

  /* Wait till LSE is ready */  
  while(RCC_GetFlagStatus(RCC_FLAG_LSERDY) == RESET)
  {
  }

  /* Select the RTC Clock Source */
  RCC_RTCCLKConfig(RCC_RTCCLKSource_LSE);

  /* Configure the RTC data register and RTC prescaler */
  RTC_InitStructure.RTC_AsynchPrediv = 0x7F;
  RTC_InitStructure.RTC_SynchPrediv  = 0xFF;
  RTC_InitStructure.RTC_HourFormat   = RTC_HourFormat_24;
  RTC_Init(&RTC_InitStructure);
 
  /* Set the time to 00h 00mn 00s AM */
  RTC_TimeStruct.RTC_H12     = RTC_H12_AM;
  RTC_TimeStruct.RTC_Hours   = 0x00;
  RTC_TimeStruct.RTC_Minutes = 0x00;
  RTC_TimeStruct.RTC_Seconds = 0x00;  
  RTC_SetTime(RTC_Format_BIN, &RTC_TimeStruct);
    /* Enable the RTC Clock */
  RCC_RTCCLKCmd(ENABLE);
 
  /* Wait for RTC APB registers synchronisation */
  RTC_WaitForSynchro();
}

/**
  * @brief  Configures the RTC Alarm.
  * @param  None
  * @retval None
  */
void RTC_AlarmConfig(void)
{
  EXTI_InitTypeDef EXTI_InitStructure;
  RTC_AlarmTypeDef RTC_AlarmStructure;
  NVIC_InitTypeDef NVIC_InitStructure;
 
  /* EXTI configuration */
  EXTI_ClearITPendingBit(EXTI_Line17);
  EXTI_InitStructure.EXTI_Line = EXTI_Line17;
  EXTI_InitStructure.EXTI_Mode = EXTI_Mode_Interrupt;
  EXTI_InitStructure.EXTI_Trigger = EXTI_Trigger_Rising;
  EXTI_InitStructure.EXTI_LineCmd = ENABLE;
  EXTI_Init(&EXTI_InitStructure);
 
  /* Enable the RTC Alarm Interrupt */
  NVIC_InitStructure.NVIC_IRQChannel = RTC_Alarm_IRQn;
  NVIC_InitStructure.NVIC_IRQChannelPreemptionPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelSubPriority = 0;
  NVIC_InitStructure.NVIC_IRQChannelCmd = ENABLE;
  NVIC_Init(&NVIC_InitStructure);
 
  /* Set the alarmA Masks */
  RTC_AlarmStructure.RTC_AlarmMask = RTC_AlarmMask_NONE;
  RTC_SetAlarm(RTC_Format_BIN, RTC_Alarm_A, &RTC_AlarmStructure);
  RTC_AlarmStructure.RTC_AlarmTime.RTC_Minutes = 2;
 
  /* Enable AlarmA interrupt */
  RTC_ITConfig(RTC_IT_ALRA, ENABLE);
 
  /* Enable the alarmA */
  RTC_AlarmCmd(RTC_Alarm_A, DISABLE);
 
}

Any help is highly appreciated.
Thanks

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