title: SIM800 gsm Module returns 0 on AT+COPS?
body: <p>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:</p>
  
  <p>AT+CMGF=1
  ERROR</p>
  
  <p>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??</p>
  
  <p>AT+COPS?</p>
  
  <p>+COPS: 0</p>
  
  <p>OK
  AT+COPS=?</p>
  
  <p>+COPS: (2,"405800","405800","405800"),(1," IDEA CELLULAR Ltd","IDEA","40404"),(1,"40505","40505","40505"),,(0-4),(0-2)</p>
  
  <p>What is going wrong here. any inputs?</p>