stm32f429 rtc alarm problem

er3481 · ‎2016-10-25

Posted on October 25, 2016 at 10:37

Hi,

I am trying to use cubemx hal library for 1 second rtc interrupt. The call back function is called every time the ''minutes'' has changed. So it does not work for every 1 second. My rtc init and call back functions are below.

void MX_RTC_Init(void)

{

/**Initialize RTC and set the Time and Date

*/

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.OutPutPolarity = RTC_OUTPUT_POLARITY_HIGH;

hrtc.Init.OutPutType = RTC_OUTPUT_TYPE_OPENDRAIN;

HAL_RTC_Init(&hrtc);

/**Enable the Alarm A

*/

sAlarm.AlarmTime.Hours = 0x0;

sAlarm.AlarmTime.Minutes = 0x0;

sAlarm.AlarmTime.Seconds = 0x1;

sAlarm.AlarmTime.SubSeconds = 0x0;

sAlarm.AlarmTime.DayLightSaving = RTC_DAYLIGHTSAVING_NONE;

sAlarm.AlarmTime.StoreOperation = RTC_STOREOPERATION_RESET;

sAlarm.AlarmMask = RTC_ALARMMASK_DATEWEEKDAY|RTC_ALARMMASK_HOURS|RTC_ALARMMASK_MINUTES;

sAlarm.AlarmSubSecondMask = RTC_ALARMSUBSECONDMASK_ALL;

sAlarm.AlarmDateWeekDaySel = RTC_ALARMDATEWEEKDAYSEL_DATE;

sAlarm.AlarmDateWeekDay = 0x1;

sAlarm.Alarm = RTC_ALARM_A;

HAL_RTC_SetAlarm_IT(&hrtc, &sAlarm, RTC_FORMAT_BCD);

}

void HAL_RTC_AlarmAEventCallback(RTC_HandleTypeDef *hrtc)

{

HAL_RTC_GetAlarm(hrtc,&sAlarm,RTC_ALARM_A,FORMAT_BIN);

//functions_1s();

if(sAlarm.AlarmTime.Seconds>58)

{

sAlarm.AlarmTime.Seconds=0;

}

else

{

sAlarm.AlarmTime.Seconds=sAlarm.AlarmTime.Seconds+1;

}

while(HAL_RTC_SetAlarm_IT(hrtc, &sAlarm, FORMAT_BIN)!=HAL_OK){}

}

Any advise ??

Walid FTITI_O · ‎2016-10-26

Posted on October 26, 2016 at 12:47

Hi rapid84,

It seems that you are using the LSI as RTC clock source. The Predivisors (127, 255) are dedicated for LSE use case. for LSI clock source case , you should use (127, 304) as (Asynch Prediv ,Synchro Prediv )

-Hannibal-

er3481 · ‎2016-10-26

Posted on October 26, 2016 at 15:19

Hi,

No, I am using external 32Khz crystal. At startup, i have to set the second to ''0'' and call the set time function, like this:

sTime.Seconds = 0 ;

HAL_RTC_SetTime(&hrtc, &sTime, RTC_FORMAT_BIN);

Otherwise the rtc alarm interrupt routine is not called until the second of the time has changed to ''0''. So i need to find the solution of calling the rtc alarm interrupt at startup whatever the second of time value is. Any advise ??

jpeacock23 · ‎2016-10-26

Posted on October 26, 2016 at 16:29

I use an STM32L152 where I set the RTC alarm to trigger on subseconds = 0, or once per second. I don't use the cube or HAL so can't give a code example.

Walid FTITI_O · ‎2016-11-04

Posted on November 04, 2016 at 10:34

Hi rapid84,

Since you haven't shared your code, I don't know how you have configurate your RTC and calendar. I recommend to have a look , to the example in STM32CubeF4 ''RTC_Calendar'' at this path : STM32Cube_FW_F4_V1.13.0\Projects\STM324xG_EVAL\Examples\RTC\RTC_Calendar

-Hannibal-

l90mehdi · ‎2017-08-20

Posted on August 20, 2017 at 16:32

hi

sAlarm.AlarmMask = RTC_ALARMMASK_All;

i tested it

it works good