sd_app_evt_wait() resets nRF52832

[genis]

That is probably an old topic, but after doing some research I could figure it out: calling sd_app_evt_wait() on my nRF5832 + nRF5 v11.0.0 SDK + s132 causes my chip to reset. That is, it enters the sleep mode (I guess it does) and when it wakes up I get main() called again and all the memory contents are lost. I wonder if that is expected behaviour or, else, the PC should resume from the same point it was after calling sd_app_evt_wait().

Also, I thought RAM retention was enabled by default so it is strange to me that my RAM changed after the wake up.

I am testing all that with the Debugger, in Keil 5.0.

[Wojtek]

I have no idea what exactly your problem is, but just to clarify - ram retention HAS NOTHING TO DO with "sd_app_evt_wait()" sleep. RAM is normally powered in that mode, so content of memory should not be lost.

[Susheel Nuguru]

sd_app_evt_wait probabably returned error and this will happen if the softdevice is not enabled.

1. RAM rentention is not enabled by default
2. RAM rentention is only relevant to system off mode, a reset will cause the contents of the RAM being lost.

[genis]

I enable the softdevice by calling "softdevice_enable()" in components/softdevice/common/softdevice_handler/softdevice_handler.c. Plus, I am advertising BLE and that's working well (I can see the adv packets from my phone), so I assume that the softdevice is enabled.

I don't understand why calling sd_app_evt_wait() causes a reset.

[Adrian Eggenberger]

If I understand you correct the reset happens not directly at the call of sd_app_evt_wait. It remains some time in the function before it resets? If you have the watchdog activated you may have a look at this question.

[genis]

I did some more testing, and it looks like this happens only when I set a breakpoint when in the line where the code calls "sd_app_evt_wait()". If I remove it, the application seems to work well. Apologies about that. Anyway, is there any explanation for that happening?