2025-08-31 11:20 PM
Hello,
I’m working on a project with the STM32WB55 where I use BLE (which is working fine) and also want to use the RTC Calendar. The project was generated with STM32CubeMX, RTC is using LSE.
The problem:
The RTC calendar runs, but its time counting is incorrect.
Instead of incrementing one minute (60 seconds), it only increments 4 seconds per minute.
What I tried:
In main.cpp, during RTC initialisation:
hrtc.Init.AsynchPrediv = CFG_RTC_ASYNCH_PRESCALER;
hrtc.Init.SynchPrediv = CFG_RTC_SYNCH_PRESCALER;
Has anyone experienced this before on STM32WB55? Any guidance or hints would be greatly appreciated.