The SIM900 GSM/GPRS Shield provides you a way to use the GSM cell phone network to receive data from a remote location. The shield allows you to achieve this via any of the three methods:
- Short Message Service
- GPRS Service
The GPRS Shield is compatible with all boards which have the same form factor (and pinout) as a standard Arduino Board. The GPRS Shield is configured and controlled via its UART using simple AT commands. Based on the SIM900 module from SIMCOM, the GPRS Shield is like a cell phone. Besides the communications features, the GPRS Shield has 12 GPIOs, 2 PWMs and an ADC.
- Based on SIMCom's SIM900 Module
- Quad-Band 850 / 900/ 1800 / 1900 MHz - would work on GSM networks in all countries across the world.
- Control via AT commands - Standard Commands: GSM 07.07 & 07.05 | Enhanced Commands: SIMCOM AT Commands.
- Short Message Service - so that you can send small amounts of data over the network (ASCII or raw hexadecimal).
- Embedded TCP/UDP stack - allows you to upload data to a web server.
- Speaker and Headphone jacks - so that you can send DTMF signals or play recording like an answering machine.
- SIM Card holder and GSM Antenna - present onboard.
- 12 GPIOs, 2 PWMs and an ADC (all 2.8 volt logic) - to augment your Arduino.
- Low power consumption - 1.5mA(sleep mode)
- Industrial Temperature Range - -40°C to +85 °C
So Far So Good ...
Posted by Steve C. on 9th Sep 2014
Good build quality and no problems. Works with my Uno and a T-Mobile pay as you go mini SIM card. SMS and voice calls working. I modified Arduino sketches posted on-line as the delay timing is critical just after sending CTRL-Z (100 ms won't work, I used 1500 as reported in some forums). Other than that, posted sketches work. Software power control works using D9. John Boxall has a good tutorial using the SIM900. Change the delay and you'll be happy with the SIM900!
AT commands slightly different than the SEEED Studio SIM900 based shield
Posted by John Stelmack on 21st Feb 2014
Once I figured out that the firmware in this must be a different version from the SEEED Studio GSM/GPRS Shield (r1.4) locating different AT Command docs was fairly easy. (I blew up the SEED Studio shield with a faulty power-supply- Fried the thing..). Reading SMS messages and deleting them works. Sending SMS via a terminal emulator and entering commands manually works well. When same commands are in a sketch it does not send. No errors given. Even running at the serial port (MEGA 2560) 9600 bps with delays between commands, it still does not send.