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

1

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?

2

Can you enter AT command after asserting wake up pin?

Btw, you can have a look on this application note

BTW, does this issue relate to this thread?

3

It looks like the issue was caused by using AT+KCELLMEAS=0. Based on the command description, I assumed that mode 0, which provides standard cell coverage details, would result in the fastest URC response. Maybe I misunderstood how it works?

In any case, switching to AT+KCELLMEAS=1,35 solved the problem for me.

Yes, there is no problem with running an at cmd.

This is what I am following to set power configs.

No, not with this thread; I think it was more relevant to the PSM issue thread than this one.

btw, I checked the issue, and the modem sw version at that time was 5.5.8. it looks like that psm issue has existed since that version.