OK, I have tried those commands.
I created two test sketches in Arduino:
- Send ATQ0, ATE1, etc., then send an SMS to my regular phone. (I have a version with both hardware UART and for newsoftserial, and they both work.)
- Send ATQ0, ATE1, etc., then start the serial relay.
What happens: it can send SMS fine, but the serial relay doesn’t seem to work.
I have attached my Saleae logic analyzer to pins 7 and 8, put the jumpers in softwareserial mode, then recorded a logic analyzer session for each program. I have attached a zip file with these sessions in both Saleae and CSV formats. I have also attached the Arduino sketches I’ve been using.
What seems to happen: I can send whatever commands I want to SIM900, and the SMS program works, but I never receive a response on pin 7.
I am close to the edge of my technical abilities in debugging this, but I’m willing to follow whatever suggestions you guys have. I do have my logic analyzer that can work up to about 16 MHz, and a pocket digital oscilloscope if that helps.
arduino-sketches.zip (1.57 KB)
gprs-logic.zip (7.45 KB)