I have been trying to fix an issue I'm having with the GSM shield for a little while now. I don't know if it is how I'm programming it, how I'm using the Arduino board, or simply GSM shield itself being limited in its design.
The problem seems to be that it doesn't continually receive text messages. It will usually receive the text messages that are waiting for it to process; the ones that were sent before the shield was turned on, that is. However, after it processes all of those, it refuses to receive any more. The thing that really bothers me is that it's hit or miss. Sometimes, it will continue to receive for a few minutes, but other times it won't continue at all. Lately, it has even started to not receive the ones that are waiting for it.
I have tested it using a battery and a wall jack as well as the USB connection and it is the same results every time.
Also, I know that the problem is not that the sketch stops running because I put in a debugging line that displays "1" every iteration of the loop and that continues to print just fine.
My code can be found here: http://pastebin.com/UiYsZexM
I also have an XBee hooked up to the board. It is connected to ports 8 and 9 because the GSM shield uses 2 and 3 to communicate with the Arduino. I know that the XBee ports are correct because I've tested them and they work.
A picture of my port setup can be found here: http://bit.ly/UtT9AO
If anyone has any ideas as to what is going on with this, I'd love to hear your thoughts. :)
EDIT: The GSM shield is placed onto an Arduino Uno. That's probably important info.
Also, I've recently noticed this capacitor. It is broken completely on one side. I've pushed it down to hopefully get a good physical connection, but it doesn't fix the issue. I'm kind of afraid to solder it, as the space is extremely small and I don't want to risk overheating the capacitor or even the IC it is connected to. Should I go for it? Haha. XD
EDIT: I should also point out that I also tried swapping the Arduino board for another one. No cigar.