GPRS registration failing


#1

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.

regards
ravee


#2

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


#3

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

https://forum.sierrawireless.com/t/power-p-current-spike/4673/6

https://forum.sierrawireless.com/t/faq-forum-wiki/3491/13

https://forum.sierrawireless.com/t/cpu-hangs/3818/2


#4

Note that there should be a lot more threads about power supply issues, but they seem to have somehow been rendered inaccessible - see: https://forum.sierrawireless.com/t/lots-of-missing-topics/4726/1


#5

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

thanks
ravee


#6

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.