RTC looses time upon system reset

[LieBtrau]

Hello,
The RTC is powered from the VBAT pin. It should be able to keep tracking time, even though the main power supply is off. According to this site that should be possible.

I checked with an oscilloscope if the LSE keeps running if the main VDD is off while VBAT is powered. That is ok.

The parameter resetTime in the rtc.begin(bool resetTime, RTC_Hour_Format format = RTC_HOUR_24); function probably allows to setup the RTC in the application without resetting its current time. It doesn't have the expected behaviour.

[fpistm]

This feature is currently not implemented.
stm32duino/Arduino_Core_STM32#266

And yes reset time will be used for that.

[LieBtrau]

Hi @fpistm, do you have any idea when this feature will be available?