STM32H5: Adjusting RTC Prescaler Periodically Not Working (Works on STM32H7)

[geoVjohnson]

In my project, I use the RTC with LSI and calibrate it by adjusting the prescaler at regular intervals (e.g., once per day). This method works well on STM32H7, but it doesn't work on STM32H5.

On STM32H5, after changing the prescaler, the RTC either stops or doesn't keep correct time.

Why is this not possible on STM32H5

[Ghofrane GSOURI · Accepted solution]

Hello @geoVjohnson 

First let me thank you for posting.

Could you please share your IOC so I can check the configuration and reproduce the issue?

THX

Ghofrane

[geoVjohnson]

This code works perfectly for me on the STM32H7. However, when I try the same approach on the STM32H5, it doesn't work. After a lot of searching, I found that some people say you cannot change the RTC prescaler on the STM32H5 due to security features. It seems the hardware keeps returning the same prescaler value as before, even after trying to change it.

[Jeevan_NM]

@Ghofrane GSOURI Same issue also here, Any solution?