Hello, I am using STM32F407ZGT6 and have the issue with time of RTC peripheral which resets to initial value after power down the board while VBAT pin is connected to CR1220 battery and LSE is used as crystal. How can I solve it?

[JTP1]

Sure, I share it little bit later. Have you measure the battery drain current with Vdd on and off, maybe it would tell something ?

[waclawek.jan]

IMO it's most likely a hardware problem.

Check *all* VDD and VSS pins (including the analog ones) and PDR_ON, being physically connected where they ought to be (measure directly on pins, suspect bad solder joints).

JW

[Aasda.3]

Thanks.

I run your code on my STM32f407ZGT board but the problem wasn't solved. Time was reset after unplugging even I programed like this code on STM32f429 Nucleo board and I had similar problem. I really don't know how to fix it ??

[Aasda.3]

I think this issue is related to software because I have similar problem on stm32f4 Nocleo board

[JTP1]

Hmmm.... Did you open the SB156 in F429- nucleo board ?

[waclawek.jan]

Which Nucleo?

Did you remove the SB connecting VBAT to VDD?

 

JW

[Aasda.3]

Thanks for your tip.

I remove the jumper and It worked properly but about the custom board the problem wasn't fixed. Current of drain in both situations was 0 A !!?

[Aasda.3]

Thanks for your tip.

Nucleo stm32f429 144 pin.

After removing jumper it worked properly although the problem of custom board hasn't been fixed.

[JTP1]

Can you share the schematic of custom board with us ?