I'm stuck. The threads I've read haven't helped with my particular issue. So here goes, any help appreciated ...
I have my DFRobot Mega connected to the Sparkfun Cellular Shield GSM/GPRS Module - SM5100B - CEL-09533 - SparkFun Electronics as per the Tronixstuff tutorial SM5100B | tronixstuff.com and am running a simple passthrough sketch.
char character = 0;
void setup()
{
Serial.begin(115200);
Serial1.begin(115200);
Serial.println("setup()");
}
void loop()
{
while(Serial.available())
{
character = Serial.read();
Serial1.print(character);
}
while(Serial1.available())
{
character = Serial1.read();
Serial.print(character);
}
}
When I run in a terminal app to be interactive with the cellular shield I get one-way communications only. Everything comes out ok:
setup()
~<0><0><0><0><0þ~~<0><0><0><0><0þ~~<0><0><0><0><0þ~~<0><0><0><0><0þ~
+SIND: 1
+SIND: 10,"SM",1,"FD",1,"LD",1,"MC",1,"RC",1,"ME",1
+SIND: 3
+SIND: 4
+SIND: 8
But when I attempt to send commands to the device, there's no response. So putting AT on the send line in Terminal v1.9b and hitting -> Send gets me nothing. Any other command I try likewise brings no response.
The code is simple. I think the passthrough function is working in both directions. I've checked my wiring and replaced the jumpers. Still nothing. I've added a 2A capable supply as per Tronixstuff's "ignore this at your peril" advice, still nada. The SIM has been tested in two phones and works. The antenna is attached. What am I missing?
Oh. And thank you! Chris.