Device reset after lte_lc_connect_async

[0sleep]

After moving from nrf9160 to nrf9151 on our prototype, our old firmware resets while trying to set up the LTE connection (this still happens when `CONFIG_RESET_ON_FATAL_ERROR=n`) I have tried various methods of debugging this, but I don't get a coredump, error handler or any other crash info (I know that the various crash logging methods work, because I can manually cause a crash on-purpose, and they do log.). I reduced complexity by testing Lesson2_Exercise2 from the cellular fundamentals course, and this reset still occurs.

I am using:

- libmodem 3.1.0-cellular-df667cc7bc9b
- mfw_nrf91x1_2.0.2
- nrf9151 on a custom PCB (WITHOUT external SPI flash)

For the devicetree config, I have modified a copy of nrf9151dk to match our hardware. Could this reset be due to some partitioning fail? What methods can I use to analyse this odd reset.

(RESETREAS register contains 0 after weird reset. I know RESETREAS should be correct, because after flashing firmware initially + automatic reset, it contains RESET reason: 65537 = RESETPIN & SREQ)

[Achim Kraus]

That's very frequently an issue of the power supply. You will find a couple of tickets here about that.

[0sleep]

Confirmed. Prototype was trying to power nrf9151 + nrf7002 off of npm1100. Cut out npm1100, power off bench supplies, connects happily. Thank you very much Achim!

[Achim Kraus]

You're welcome.

[Michal]

nPM1100 does not have the current capabilities for nRF9151 and nRF7002.

For nRF9151 you can use the VSYS pin on the nPM1300 (but you'll also have to add extra filtering on the outputs compared to the reference design, we can help out with that on a case-by-case basis currently).

Unfortunately, for nRF7002 you cannot use the VSYS pin directly (and neither the integrated bucks/LDOs, their current capability is too low), since nRF7002 is not 5V-tolerant, so you'd have to add something like a buck converter (with passthrough), or have some other way to limit the voltage goint to the nRF7002 to 4.5V maximum.

Best regards,

Michal