GPRS Shield & Yun - doesn't seem to receive data

Hi there,

I've had a rather frustrating few weeks with the Seeedstudio GPRS Shield v2. I can get the shield to send an SMS most of the time - but I can't for the life of me seem to receive (or at least process) any data from the shield.

Whenever I attempt to GPRS->read(); it only returns a 0.

I am using the Yun, software serial pins 7 and 8 and have a ridiculously simple sketch to that echoes commands from the serial monitor to the shield. I believe I'm correctly terminating the AT command strings with \r\n.

  • I'm powering the Yun and shield via USB mini.
  • The shield has a network connection: the green power led is on, the red led on, and the green network led is flashing every 3 seconds.

I've attempted without success:

  • changing the baud rate between 2400 and 19200.
  • changing the pins from 8,7 to 10,11.

I've looked high and low across the internet for help, but found nothing. Does anyone have any thoughts please?

Thanks so much!

Are all the jumpers on the shield set correctly?

Have you tried to just hook it up to power and a USB-serial adapter (TX/RX/GND) and use it over serial(with no Yun involved, just the shield) and see if you can make that work? That's a really great debugging step in any sort of serial device.