nRF52810 ble app template example failed when go to system off

[Ars Morozov]

Hello. I met trouble, presented in the name of the thread. I use example for PCA10400e board. So, what I've changed to accelerate reproducing of this error. I change logger interface from uart to rtt and I change definition APP_ADV_DURATION to 1000. And don't make any other changes in project.

It always dropped in app_error_fault_handler form app_error_handler_bare() by following calling:

app_error_fault_handler(NRF_FAULT_ID_SDK_ERROR, 0, (uint32_t)(&error_info));

I use SDK 15.3, nrf52810 on my custom board, to flash it I use nrf52-dk (PCA10040). Softdevice - s112 v6.1.1.

[Edvin]

Hello,

Are you by chance debugging when you go to system off? This will not work, because system off is actually just turning off the device (almost). Hence, when you are debugging, and it can't turn off, it will throw an error. 

[Ars Morozov]

Hm ok. Thank you. Is it written somewhere in documentation? I skip it?

[Edvin]

It doesn't say in the documentation actually, but it doesn't make much sense to be able to debug when the device is going in system off. Getting information from the device after powering off the chip. When you are debugging, the chip enters an emulated system off, in which the sd_power_system_off needs to return something, so it returns NRF_ERROR_SOC_POWER_OFF_SHOULD_NOT_RETURN. when this is passed into the error handler, it will trigger.

In real life, when not debugging, you can consider your application as "done" after sd_power_system_off(), and it will go to deep sleep until it receives a physical interrupt, from where it will restart from the top of main(). 

Please check out the answer from my colleague Susheel in this post:

https://devzone.nordicsemi.com/f/nordic-q-a/15677/why-does-nrf52-hrs-sdk11-example-sd_power_off-return-6#post-id-90460

This one also explains it:

https://devzone.nordicsemi.com/f/nordic-q-a/17016/problem-with-emulated-system-off-mode-with-nrf52#post-id-98831

Best regards,

Edvin

[Ars Morozov]

Edvin, thank you very much for the answer and for this usefull links. I didn't know that in debug mode proceesor enter in EMULATED SYSTEM OFF.