RTC Drift

MHaji.1 · ‎2024-09-07

Hi,

I have a custom board by STM32H743 and have some problems by RTC. I've used LSE with a 32.768 KHz external crystal. I have 2 or 3 seconds more in each minute. There is no reset within 3 minute and I see about 15 second more.

I've used 6.8 pF for CL1 and CL2...

Please help me.

MHaji.1 · ‎2024-09-07

Hi,

It seems bad register writing is the main cause, before set time or date, all of parameters should be initialized like WeekDay and etc, if not, some wrong numbers will write to registers and LSE change to LSI because of errors...

After initializing all parameters and then writing them, problem is solved... I'm writing this, hoping solve others problem..

Thanks.

View solution in original post

MHaji.1 · ‎2024-09-07

Hi,

It seems bad register writing is the main cause, before set time or date, all of parameters should be initialized like WeekDay and etc, if not, some wrong numbers will write to registers and LSE change to LSI because of errors...

After initializing all parameters and then writing them, problem is solved... I'm writing this, hoping solve others problem..

Thanks.