GPRS registration failing


Hi ,
I’m using TCP client sample code provided in the open AT for Q2686 module,

Its ran well on the evaluation board then I put the module and sim to my own designed board ,
After putting there its not registering to the network, its keep on polling at the poll_creg_callback function . I checked the sim connection, Gnd antenna connection, all are correct and as per the reference board.
I’m using airtel service provider.

Pls help me to solve this problem.



What’s the response to AT+CSQ? and manual call to AT+CREG?
Its a bit difficult to remotely debug someones hardware.


Good, solid ground and power connections to the module are vital:


Note that there should be a lot more threads about power supply issues, but they seem to have somehow been rendered inaccessible - see:


Its working now . There was some problem at the bypass capacitor of power part, Now I have put 10microF cap …



When a GSM device (any GSM device - not just SiWi) transmits, it draws a huge peak of current - so, obviously, this is where any deficiencies in your power supply arrangements are going to show up!

This is why your board could start, and communicate with the board - neither of which takes much current - but then failed to register.