Unable to store the time of RTC in STM32F042k6 when connected to Duracell DL2032 Battery.

[ABogg.1]

Hello all,

I am unable to save time or restore proper time after I remove Vdd from my MCU when connected to a external 3V li ion battery (DL2032). After every power cycle my time gets reset to its initial default value.

When I supply 3V from a regulated power supply RTC time works as expected. Can anyone please suggest me what kind of external batteries are to be used for STM32F042k6 or is there a special circuit that I should follow?

Thanks in advance!

Amith B G

[ABogg.1]

thanks for the reply. So, it is not possible to have RTC clock time by using using the STM32F042K6?

regards,

Amith B G

[Peter BENSCH · Accepted solution]

It is possible to use the RTC with the STM32F042K6 if the MCU is powered by VDD. As long as VDD is supplied, the RTC will also run in STOP mode.

But it is not possible to buffer the VBAT domain due to the missing VBAT pin.

Regards

/Peter

[ABogg.1]

Thanks for the detailed explanation.:-)

regards,

Amith B G