No URCs or Network Recovery After Wake-Up From Hibernate (CEREG:4 Stuck)

[zsen]

Modem fw: HL7812.5.5.17.0-24.03.0.FreeRTOS.w10

We’ve made some progress on this issue Unexpected GPIO6 and fast shotdown pin Behavior When Trying to Enter PSM on HL7812 – Not Matching Docs. After setting AT+KSIMDET=0, the device is now able to enter sleep modes correctly, in my case, it successfully goes into hibernate.

However, I’m now running into a new problem: the device never wakes up from hibernate after I assert the wake-up pin. It also doesn’t transition from CEREG:4 (not registered) to CEREG:5 (registered, home network), even after the wake-up signal.

Wake-up Procedure I Followed:

1. Assert the wake-up pin (set it high).
2. Wait for a +KCELLMEAS URC (or any sign of life from the modem).

But nothing happens — I don’t receive any URCs, and the modem stays stuck in CEREG:4.

Should I open a new issue to track this wake-up behavior, or is it okay to continue the discussion here?

[jyijyi]

Can you enter AT command after asserting wake up pin?

Btw, you can have a look on this application note

HL78xx - Low Power Modes Application Note

BTW, does this issue relate to this thread?

Unexpected +KCELLMEAS URC prevents PSM from functioning properly

Yes, here is a log that shows psm works good without KCELLMEAS=1,10. I think the problem may not be the KCELLMEAS here, As you said here, something is waking up the module, and automatically I am getting kcellmeas after 10secs as it is expected according to the reference guides. I think the psm loop issue occurs because of my software, that doesn’t expect that much quick kcellmeas. The problem is that the first wake up by something we dont know ATM. +CEREG: 4,,,,,,"00001111","00001111" 3957…