SIM800 gsm Module returns 0 on AT+COPS?

Question

I am using SIM800 Module with Arduino Micro. It reponds well to basic AT commands. But i am unable to send SMS from this module as:

AT+CMGF=1 ERROR

Now while further debugging i saw AT+COPS? Returns 0, means not connected to any operator. That may be causing the CMGF failure. But my AT+COPS=? returns multiple operator. I have an Airtel working sim. Intialyy it was showing AIRTEL too in AT+COPS=? but not now.. anything to do with signal??

AT+COPS?

+COPS: 0

OK AT+COPS=?

+COPS: (2,"405800","405800","405800"),(1," IDEA CELLULAR Ltd","IDEA","40404"),(1,"40505","40505","40505"),,(0-4),(0-2)

What is going wrong here. any inputs?

Answer 1

Go to an area where the signal strength is pretty good. Check for AT+CSQ, this will tell you the signal strength. Do check for AT+CMEE=1 for error report.

Answer 2

Might be some power issues, but I fixed mine by just trying some AT command

AT+CBAND?

Then, AT+CBAND="DCS_MODE"

That works for me. Give it a try man.

Answer 3

It seems there's no service for your network close to you. The module is unable to register with the network. The command AT+CREG? will probably give you +CREG: 0,3 meaning it couldnt connect. AT+COPS=? is a query that yields the possible options for the result of a command or its inputs. Move your circuit to another location and see if AT+CREG? returns +CREG: 0,1 or +CREG: 0,5 which signifies a valid network registration.