NRF9151DK autonomous resets when simultaneously starting LTE connection and GPS on modem FW 2.0.2

[Sebastiaan Merckx]

I have updated a board (NRF9151DK) from modem FW 2.0.1 to 2.0.2. The board is also equipped with nrf7002-EK, and the support for the wifi driver is enabled (SB_CONFIG_WIFI_NRF70, SB_CONFIG_WIFI_NRF70_SCAN_ONLY, haven't verified if this makes a difference).

The previous version of the application works fine, in which we initialize the modem at startup, and simultaneously initiate an LTE connection and activate the internal GPS. On the new 2.0.2 firmware, this simultaneous action results in an autonomous reset, which can be fixed by e.g. adding a 100msec sleep before activating the internal gps. The same problem occurs on other devkits too (observed on 2 out of 2).

I mainly want to notify you of this difference, because I'll not be the only person suffering from this. I leave it up to you to consider if a fix is possible.

I can try out alternative solutions if necessary.

Best regards,

Sebastiaan

[Sebastiaan Merckx]

I just observed that a 100msec sleep is not always sufficient, I have now just increased it to 1 second to be safe.

[Susheel Nuguru]

The first thing that comes to my mind when you say autonomous resets is that this should be trackable. Can you put a breakpoint in the sys_reboot() function, run the application in debugger and let the breakpoint hit. When you look at the function call stack at this point it will give us more context on why this is happening and we can take it from there on how to avoid or workaround.

[Sebastiaan Merckx]

Hi Susheel,

I rather think this is a brownout reset. The function sys_reboot() is never hit.

[Susheel Nuguru]

Sorry for late response. Then you should be able to read the reset reason

If you see 0x00000004 then it is a brown out reset and then we need to see if your power source is stable.

[Sebastiaan Merckx]

Are you sure this command exists? I can't find it in the documentation https://docs.nordicsemi.com/bundle/ref_at_commands_nrf91x1/page/REF/at_commands/intro_nrf91x1.html and I also couldn't get it to work, it returns ERROR while e.g. "AT%DEVICEUUID" does provide a response.