Modem stops responding after CFUN? and modem trace lib crashes

RE: Modem stops responding after CFUN? and modem trace lib crashes

Michal — Tue, 14 May 2024 21:41:42 GMT

Hello,

Does it always take a long time to connect after flashing/modem factory reset?

Best regards,

Michal

RE: Modem stops responding after CFUN? and modem trace lib crashes

Mikael Jansson — Tue, 07 May 2024 16:39:42 GMT

Hello Maria,

Thanks for the quick reply! Important note: after this first stall/long wait, from boot to fully connected now takes just a few seconds.

[quote userid="116814" url="~/f/nordic-q-a/110911/modem-stops-responding-after-cfun-and-modem-trace-lib-crashes/482335"]Have you had us do a hardware review for your board?[/quote]

Nope.

The board is designed by another local company with long experience of the nRF chipset family, and they've basically copied the power supply from their reference design to our board.

Anyway, the main power input is 12V from Eaton 3S Mini UPS[1] that I think should provide 3A, feeding a AP64200 [2] with 2A continuous, in turn feeding VDD1, VDD2 at 5V. VDD_GPIO is fed by AP7354 [3] giving 3.3V at 150mA.

[1] https://www.eaton.com/gb/en-gb/catalog/backup-power-ups-surge-it-power-distribution/eaton-3s-mini-ups---emea.html

[2] https://www.diodes.com/assets/Datasheets/AP64200.pdf

[3] https://www.diodes.com/assets/Datasheets/AP7354.pdf

[quote userid="116814" url="~/f/nordic-q-a/110911/modem-stops-responding-after-cfun-and-modem-trace-lib-crashes/482335"]The tfm-enable-share-uart snippet was introduced in NCS v2.6.0. Have you added the snippet to NCS v2.5.2?[/quote]

Yeah, made no difference though, so I scrapped that route. :-)

RE: Modem stops responding after CFUN? and modem trace lib crashes

Maria Gilje — Tue, 07 May 2024 14:41:47 GMT

Hi Mikael,

[quote user=""]

For no reason, whatsoever, the modem suddenly started working and I have absolutely no idea why. I did nothing different.

Is it that the modem hangs - or seems to hang - when it's registering the SIM on the network? It's impossible to tell, and I really do think it should respond to AT commands during that time.

[/quote]

My colleague is setting up a test to try to reproduce the hanging issue. Depending on the results we could have an explanation on why the modem (appears to) hang. Thank you for your patience on this.

That being said, a possibility could be that the power supply on your board is not sufficient to supply the modem during network registration. Have you had us do a hardware review for your board?

[quote user=""]Tried various options, including -S tfm-enable-share-uart to force it to uart0, to no avail.[/quote]

The tfm-enable-share-uart snippet was introduced in NCS v2.6.0. Have you added the snippet to NCS v2.5.2?

Best regards,

Maria