(Urgent) Riverdi 7" STM32 Embedded Display RTC not working when power is off.

[purushotham2608]

Hello Everyone, good day, Recently I have implemented RTC to my TouchGFX project for my Riverdi RVT70HSSFWCA0 STM32 Embedded Display that uses a STM32H757XIH6 Microcontroller. I have managed to get the time and date to show on the display, all is working well. Except that the RTC is only running when the power for my display is on even though I placed a battery at the back of my display (which is connected to the VBAT pin of the stm32) The battery has 3 V coming out so its not a battery problem. I do not know why it is not running while the power is off, can anyone help me with this? Do I have to write any code for the display to be able to use the battery? Please provide kind support, thank you best regards.

[Peter BENSCH]

Well, this is not a board from STMicroelectronics, but from Riverdi, so Riverdi or its forum should be able to answer your question. I cannot even find the schematics of that board.

What does the programme you used to address the RTC look like?

Regards
/Peter

[purushotham2608 · Accepted solution]

Hello, good day. I have contacted Riverdi through E-mail as they do not have any forums. this is what they said :

So I guess it means Riverdi Boards can't run RTC when power is off. Thank You Best Regards.

[Peter BENSCH]

Thanks for posting the feedback! However, Riverdi's answer is slightly different: the RTC cannot be used IN THIS, i.e. the board revision you have, because the LSE Crystal is apparently missing. However, this will be corrected in the next revision, so that the RTC will then (hopefully) be usable.