This LinkSprite GSM/GPRS shield has PCB etched antenna, so no need for external antenna.
The shield must be powered by a wall adapter with 12V, 1A, like this one: http://www.cutedigi.com/product_info.ph ... ts_id=4184
1. RX jump to MRX, TX jump to MTX, and remove the atmega328P from arduino.
By doing this, we can directly monitor serial port output using the USB port.
The default baud rate is 115200.
2. Install X-CTU serial terminal console:
Now we are going to use atmega328P's UART to talk to USB, and soft serial of atmega328P to talk to ATWIN.
Before we do that, we have to change ATWIN's data rate to 9600 as soft serial can't go to 119200.
In first tutorial setup, do: AT+IPR=9600 to set the baud rate to 9600.
Now set the jumper RX to D3, and TX to D2. SO that atmega328P's UART to talk to USB and soft serial of atmega328P to talk to ATWIN: