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rtc & stm32f429

alireza_roozitalab
Associate III
Posted on August 03, 2014 at 19:10

hello every one i need to use lse for rtc clock src. because i want it still working at the power of( with vbat)

my lse circuit work correctly because i use the mco1 as lse clock src and i have 32.768 khz this pin (pa8).

my sample code is :

  RCC_APB1PeriphClockCmd(RCC_APB1Periph_PWR, ENABLE);

  PWR_BackupAccessCmd(ENABLE);

 RCC_LSEConfig(RCC_LSE_ON);

  while(RCC_GetFlagStatus(RCC_FLAG_LSERDY) == RESET)

  {

  }

  RCC_RTCCLKConfig(RCC_RTCCLKSource_LSE);

  RCC_RTCCLKCmd(ENABLE);

  RTC_WaitForSynchro();

  RTC_TimeStampCmd(RTC_TimeStampEdge_Falling, ENABLE);   

    RTC_InitStructure.RTC_AsynchPrediv = 0xff;

    RTC_InitStructure.RTC_SynchPrediv =0x7f;

    RTC_InitStructure.RTC_HourFormat = RTC_HourFormat_24;

and use :

  RTC_GetTime(RTC_Format_BIN, &RTC_TimeStructure);

 RTC_TimeStructure.RTC_Hours, RTC_TimeStructure.RTC_Minutes, RTC_TimeStructure.RTC_Seconds

as time value but they are always zero!

but if i change the clock src to lsi , it works correctly
1 REPLY 1
Posted on August 04, 2014 at 01:20

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