No Connection to Network: +CREG: 0,0

I've a MKR 1400 Board with SIM, Antenna, and Lipo attached. The TestModem sketch works fine. When trying the GSMScanNetworks sketch with the only change in line 30:

GSM gsmAccess(true);     // include a 'true' parameter to enable debugging

I get the following output: (The full output is given in the attachment)

[...]
AT+CREG?

+CREG: 0,0

OK

This part is repeating itself a number of times till the board hangs.
When I google the result I understand, that the first 0 of +CREG: 0,0 means their will be no message when changing the connection status, which is OK. The second zero tells that the board is not connected to a network but it is not searching for a connection either.
Why is the board not looking for a connection?
Why does it hang?
I will be gratefull, if someone could share their ideas.

OutputGSMScanNetworks.txt (1.09 KB)

Are you certain that the SIM has been activated, and with the device's IMEI number?

The TestModem sketch does not require a SIM card to work. Can you run that sketch again and post your Serial Monitor output?

I'm facing the same problem with my MKR GSM 1400.

The TestModem sketch displays the following output in the console, which seems to be correct:

Starting modem test...modem.begin() succeeded
Checking IMEI...Modem's IMEI: 357520074865730
Resetting modem...Modem is functoning properly

But when running the GsmScanNetworks sketch, as described above by bbiehler, boards seems to hang after some time. I attach the console output.

I have been stuck with this already for a few days and I don't actually know what else I can do.

Could any of you please give me some advice? Any help to find out what's wrong with my MKR GSM 1400 board would be welcome.

GsmScanNetworks_console_output.txt (926 Bytes)

Do you have a Lipo battery connected to the board as per the product page?

Yes, I had a LIPO battery connected to the MKR GSM 1400 board. I have also tried with a 5V/2,1A power supply connected to VIN, but I got the same result in both cases.

Hi,

I got also the exact same problem that @mrcarrera ...
I'm using an external power supply 5v 3A, a working sim card and a gsm antenna.
The "TestModem" code provided by the MKRGSM library works perfectly by providing the correct IMEI number of my board.
But with the "GsmScanNetworks" the serial monitor is printing always the same thing and get stuck with those same lines : AT+CREG? +CREG: 0,0.
What could possibly be wrong?
Has someone that already face this issue beeing able to solved it?

GsmScanNetworks_SerialMonitor.txt (1.53 KB)

I'm in the same boat - anybody found a solution for this?

Quick update - got this working by making sure the SIM works fine in a normal phone and then placing it in the board and running it off external power. Definitely looked like a power issue, but has since disappeared.

Thanks, guys!

ThomasArduino:
Hi,

I got also the exact same problem that @mrcarrera ...
I'm using an external power supply 5v 3A, a working sim card and a gsm antenna.
The "TestModem" code provided by the MKRGSM library works perfectly by providing the correct IMEI number of my board.
But with the "GsmScanNetworks" the serial monitor is printing always the same thing and get stuck with those same lines : AT+CREG? +CREG: 0,0.
What could possibly be wrong?
Has someone that already face this issue beeing able to solved it?

External power ok
Simcard ok
Imei ok

Same here:

8:12:12.456 -> +CPIN: READY
18:12:12.456 ->
18:12:12.456 -> OK
18:12:12.665 -> AT+CMGF=1

18:12:12.665 -> OK
18:12:12.874 -> AT+UDCONF=1,1

18:12:12.874 -> OK
18:12:13.084 -> AT+CTZU=1

18:12:13.084 -> OK
18:12:13.258 -> AT+UDTMFD=1,2

18:12:13.258 -> OK
18:12:13.465 -> AT+CREG?

18:12:13.465 -> +CREG: 0,0
18:12:13.465 ->
18:12:13.465 -> OK
18:12:13.670 -> AT+CREG?

18:12:13.670 -> +CREG: 0,0
....

TEST SIM:
18:21:37.312 -> AT

18:21:37.312 -> OK
18:22:27.976 -> AT+CMEE=2

18:22:27.976 -> OK
18:23:07.287 -> AT+CPIN?

18:23:07.287 -> +CPIN: READY
18:23:07.287 ->
18:23:07.287 -> OK

simcard work perfectly on sim900
tested with both option: LIPO 3.7 or VIN 5v 2.1amp
same results

I have some recollection about needing a different sim card to work on 2g and 3g networks? Have you tried your simcard in a smart phone and been able to browse the web or similar?

I have the same problem.
The sim card works perfectly in my computer.
I have a 2000mAh LiPo battery.

And I have the hangup as described above. Does anyone have a good root cause?