I have some problems with my GPRS shield on a Duemilanove: it doesn’t respond to AT commands at all.
Here is my setup: everything powered over USB from a Windows computer. No other shields mounted. SIM card and antenna installed. I am running the simple NewSoftSerial based example and the jumpers are set correctly.
When I initially power the board on, only the PWR LED is on, After I press the power key, first D1 comes on and then the red Status/D2 LED comes on. After about 10 seconds, D1 starts blinking very briefly every 3 seconds or so. D2 stays on.
At this point I try to send commands such as AT and AT+COPS with a CR efter (although I’ve also tried LF and CRLF). I have hooked up a Saleae logic analyzer and I can confirm that the Arduino is, in fact, sending the AT\r command correctly on pin 8, when I hook up the async serial analyzer and set it to 19200 8-N-1. The GPRS never responds with anything on pin 7 (or, for that matter, pin 0). I never see the RDY message that I’ve seen in some screen shots; in fact pin 7 is completely quiet, at least when captured at 1 MHz which should be enough to capture serial.
Are there some things I can do to troubleshoot this?