RTC lost time after reset

[chief]

Posted on October 01, 2015 at 14:14

I've STM32f417IF. I try to user RTC. All Init code writed by STMCubeMX. Then i set date and time, but after reset RTC time clean again.

RTC have own big capasitor and i just make reset, without poweroff.What is wrong?upd.I'm idiot. Standart Cube's init set zero time. Moderator, pls remove this stupid topic.

[thomfischer]

Posted on October 02, 2015 at 21:04

in function void MX_RTC_Init(void)

disable HAL_RTC_SetTime(&hrtc, &sTime, FORMAT_BCD); HAL_RTC_SetDate(&hrtc, &sDate, FORMAT_BCD);

[Walid FTITI_O]

Posted on April 14, 2016 at 16:23

Hi RiseOfDeath,

I think your issue is coming from the fact that your code is confusing between the power-ON and the resuming from Standby mode.

So, you should proceed like the following:

/* Check and Clear the Wakeup flag if already set*/ 
if(__HAL_PWR_GET_FLAG(PWR_FLAG_WU) != RESET) 
{ 
__HAL_PWR_CLEAR_FLAG(PWR_FLAG_WU); 
} 
/* Check the status of standby flag SB*/ 
if (__HAL_PWR_GET_FLAG(PWR_FLAG_SB) == RESET) 
{ 
/* Power-ON routine */ 
- Clearing all flag 
- RTC configuration 
- Entering standby routine 
} 
else 
{ 
/*Resuming from standby routine */ 
……….. 
} 

You should also, make attention when you want to debug a low power mode, in this case you need to Enable the debug for that mode :

For standby mode debug:

/* Enable the Debug Module during STANDBY mode */

HAL_EnableDBGStandbyMode();

I recommend that you take a look to the application note AN4538 at this

http://www.st.com/web/en/resource/technical/document/application_note/DM001214pdf

: “Power consumption optimization with STM32F3xx microcontrollers “

Yo

u will be inspired from this AN where we have developed a use case similar to your application where all the power modes are used and it containes a (Power-On /standby resume) switching routine. You find the firmware at this

http://www.st.com/web/en/catalog/tools/FM147/CL1794/SC961/SS1743/LN1734/PF257872

.

-Hannibal-