RE: System OFF/ wake up with NRF51822

Witali — Wed, 18 Sep 2013 13:47:13 GMT

Hi Ole,

thank you for your reply.

I was able to find a workaround by using the GPREGRET register.

RE: System OFF/ wake up with NRF51822

Ole Morten — Tue, 03 Sep 2013 12:30:39 GMT

The alternative to system off is called system on, idle, and is entered by doing a __WFI() call. When you wake up from this state, execution will continue from where it left off, and not cause a reset. You therefore need to make sure that this is handled appropriately.

Using this power saving mode instead of system off is the only way to avoid reinitalization completely, and this would also remove your other problem with buttons not being correctly detected on startup.

The alternative is to check which buttons are pushed on startup and act appropriately. There isn't any way to know which button woke you up when using the GPIOTE port event, so you have to check each button and do whatever is needed manually.