SIM808/868 - Was working, now not connecting with response +CREG: 0,2 and +CREG: 0,3

[Anthony]

I’ve been working with a SIM808 and SIM868 and have been able to connect with no issues on both setups with different SIM cards in my account with no problems. Yesterday around 1:30pm EST both SIM cards stopped working in both devices. I don’t see anything wrong with my account as far as I can tell. I have credit in my account and both SIMs show as active and there is no cap on the data limit.

When I try and connect I get the following now:

AT+CREG?
+CREG: 0,2

…and then after multiple attempts it changes to this:

AT+CREG?
+CREG: 0,3

I’ve tried to force it by sending: AT+CREG=1 and AT+CREG=2 but still get the same results.

I’ve been working on developing on sending parameters on the Hologram Cloud and was making great progress. I am almost at the point to test the difference in bandwidth consumption between the Hologram Cloud API and using GET to update values but now it won’t even connect.

Any help would be greatly appreciated! One of the cards is the COMBO MINI/MICRO/NANO SIM and the other is the INDUSTRIAL GRADE SIM. I’m going to try another new SIM card in the modems to see if that may be the cause? I couldn’t imagine them both going bad at the same time though.

Thanks as always for your help in advance!

Thanks,
Anthony

[Anthony]

I registered a new Hologram SIM card and it shows that it’s active on my dashboard and everything appears to be functioning normally. I’ve tried connecting almost a full 24 hours now and still can’t get any of the SIMs or modems to connect.

Just to troubleshoot an issue in my code, I’ve restored all the code back to several different versions prior to having the connection problems. I even went back to a few days before experiencing the issues. I didn’t change any of the connection code with the AT commands…it was more formatting and other ares of the code.

I’ve tried to switch out the antenna and drive close to several towers that are mapped on this site (https://www.cellmapper.net) but I never had issues with the signal strength or quality from either device since it was set up several weeks ago.

Not sure if there is anything else that would affect this? I was thinking a SIM code but I’ve never set one and when it runs AT+CPIN it gives a “Ready” response so I’m thinking that’s not it.

Here are some of the commands I’ve sent. There is some extra information that I send out to the terminal so you can disregard some of the info:

Initializing modem…
AT
OK

AT+CLTS=1
OK

AT&W
OK

AT+CFUN=0
+CPIN: NOT READY
OK

AT+CFUN=1,1
OK

AT
OK

AT&FZ
Call Ready
OK
ATE0
ATE0
OK

AT+CPIN?
+CPIN: READY
OK
ATI

SMS Ready
SIM808 R14.18
OK
Status: SMS
Version: Ready SIM808 R14.18

Status: AT+CIPSSL=?
ERROR
SSL is not supported by this modem

Starting GSM
Waiting on network…

AT+CREG?
+CREG: 0,2
OK
…(after repeating this for a while)
AT+CREG?
+CREG: 0,3
OK

AT+CREG=1

AT+CREG?
+CREG: 1,2
OK
…(after repeating this for a while)
AT+CREG?
+CREG: 1,3
OK

As a couple additional notes: GPS does work on the modem and it picks up satellites and is able to connect. When I try and list the operators this is what I get:

AT+COPS=?
+COPS: ,(0-4),(0-2)

Thanks again for all your help!!

[Maiky]

Hey @Anthony,

Can you please run this modem diagnostic and email it to success@hologram.io. So we can take a closer look at what might be going on.

Thanks!

Cheers,
Maiky

[Anthony]

You should have the responses to the commands in your inbox

Thank you!

[Anthony]

Thanks again for all your help @Maiky! It looks like it seems to be an issue with T-Mobile service in my area. Things started working again yesterday intermittently and seem to have stabilized now.

I appreciate your quick response and working with me to troubleshoot as always!