How Can I Change RTC clock to external oscillator？
You need to spin your own board design and modify the firmware. This isn’t something we can support you on.
yes，I design my PCB and external oscillator is added，but I still not sure How to set registers in micropython。
We don’t really know either as it’s not something we support.
The PYB module is the same for our board and like the pyb board however. So, whatever works for the pub board should work for the OpenMV Cam.
Thanks！ I got it！