NRF54L15-DK deep sleep, wake up via RTC

[Nikollao]

I am trying to wake up the NRF54L15-DK from deep sleep using RTC. The device goes into deep sleep but never wakes up. I would like to know if RTC can wake up the micro from deep sleep. Is it something I am doing wrong or is this not possible at all? 

[Håkon Alseth]

Hi,

 

There is a sample that shows wakeup from system off with the nRF54L-series devices in zephyr/samples/boards/nordic/system_off, where specifically this logic is what enables the GRTC to run in systemoff mode:

https://github.com/nrfconnect/sdk-zephyr/blob/main/samples/boards/nordic/system_off/src/main.c#L100-L108

 

Remember to set "CONFIG_GRTC_WAKEUP_ENABLE=y" when evaluating.

 

Kind regards,

Håkon

[Nikollao]

Hi, Thanks for the response. When setting CONFIG_GRTC_WAKEUP_ENABLE=y in the prj.conf file, debug fails. Any idea why? Sorry, I am new to the NRF environment. 

[Håkon Alseth]

Hi,

 

Happy to help out.

Debugging while entering systemoff is generally not easy, because this is a mode where (mostly) combinatory logic is powered + the GRTC, while the active SWD debug interface requires certain CPU parts to run to work as intended.

Due to this, we have a "emulated system off mode", which will not work entirely as the function does without debug mode:

https://docs.nordicsemi.com/bundle/ps_nrf54L15/page/pmu.html#ariaid-title5

 

We recommend that you add a while(1) loop after, to ensure that you do not debug/step further.

 

Kind regards,

Håkon

[Nikollao]

Sorry my mistake, build fails. so I am trying to write  CONFIG_GRTC_WAKEUP_ENABLE=y in my .conf file but this does not build. I intended to flash only, not debug. 

[Håkon Alseth]

Can you share the output?