How to avoid going back to sleep after waking up from Timer interrupt?

RE: How to avoid going back to sleep after waking up from Timer interrupt?

Kenneth — Wed, 15 Feb 2023 12:50:21 GMT

Because it just woke up to go to sleep again in that case, so you should only have one entry to sleep (which you now have).

Kenneth

RE: How to avoid going back to sleep after waking up from Timer interrupt?

Ron — Wed, 15 Feb 2023 12:22:36 GMT

Yes, That was the case,

But why would that cause what I described?

RE: How to avoid going back to sleep after waking up from Timer interrupt?

Kenneth — Wed, 15 Feb 2023 12:02:05 GMT

Hello,

nrf_pwr_mgmt_run() is a wrapper around sd_app_evt_wait() so that is fine.

(I suspect you were using both nrf_pwr_mgmt_run() and sd_app_evt_wait() in your while loop previously then?)

Kenneth

RE: How to avoid going back to sleep after waking up from Timer interrupt?

Ron — Tue, 14 Feb 2023 17:54:19 GMT

Hi,

I do have softdevice enabled, I am using nrf_pwr_mgmt_run(), and it seems to go to sleep just fine, so why is the sd_app_evt_wait() necessary? do they not serve the same function?

Thanks

RE: How to avoid going back to sleep after waking up from Timer interrupt?

Kenneth — Tue, 14 Feb 2023 15:33:51 GMT

Hi,

You should be using sd_app_evt_wait() to go to sleep (when you have a softdevice enabled), however sd_app_evt_wait() should only be called one place: in the while-loop in main. Do not use _WFE() or _SEV() if you have a softdevice enabled.

Kenneth

RE: How to avoid going back to sleep after waking up from Timer interrupt?

Ron — Tue, 14 Feb 2023 12:38:00 GMT

Hi Kenneth

I further investigate and compared, the problem seems to be me calling the function - sd_app_evt_wait();

I removed it and now it works. I also checked my sleep current consumption and it seems to be as low as before

So I am not sure why I place the sd_app_evt_wait() there in the first place, nor do I know why would it cause the issue I described.

Thanks!

RE: How to avoid going back to sleep after waking up from Timer interrupt?

Kenneth — Tue, 14 Feb 2023 10:08:34 GMT

Hello,

This is one of those issues I would expect to occur infrequently, in other words it may sometimes happen if the interrupt event handler is called right before the while-loop in main want to go to idle (sleep), but if it happens continously I would likely have looked at your while-loop and compared it with the ble peripheral examples. Edit: Maybe even consider a 1us delay on wakeup from idle in main() before checking flags etc and going back to idle.

Kenneth