Arduino 3G shield

Question

I have an Arduino UNO and a 3G shield ( http://imall.iteadstudio.com/development-platform/arduino/im121026002.html ). To connect to the internet I had only to configure the APN once which the SIM provider gave me and write the PIN number via AT commands in the setup() function, that's all.

I have some questions:

1) the internet key which the SIM belongs to comes with a software you have to use to connect to the internet: each time you want to connect you press CONNECT and when you are finished you press DISCONNECT. The 3G shield on the contrary needs only APN and PIN and that's it: am I forgetting anything? The module works, therfore I don't think so: what's your experience?

2) the internet key software needs to be configured with a "Dial Number" too, which I don't know what's for. The 3G shield works without any "Dial Number": any idea why?

3) sometimes while surfing the internet with the internet key, you loose the connection (maybe the provider kicks you off). In that case you have to click connect and you are in again. If something like that happens with Arduino+3G what do I have to do? I tried resetting the 3G module via the reset pin, but the module cannot register any more into the network.

Thank you in advance

Answer 1

1.) It sounds as though the 3G shield is set up to automatically connect to the internet when it is powered on, and the setup function does this. Depending upon the design of the software supplied with your internet key, you may be able to configure it to do the same thing, so that you wouldn't have to press Connect/Disconnect each time.

2.) The 3G shield probably uses a default dial number like 99**1#.

3.)If the connection is lost due to external factors, e.g. the network dropping the connection, then the 3G shield probably tries to re-connect automatically. If the connection is lost because of a problem in the shield, then powering it off and on again will probably do the trick, but you will have to enter the PIN again of course.
At a guess, the reset button may lock the SIM again, and that's why it appears to lose the network. It sounds as though you would have to run the setup function again, to unlock the SIM and connect to the network.