SIM900 GSM GPRS shield is based on a chip of SIM900 from SIMCOM and is compatible with Arduino and its clones. It is used to make and receive phone calls, send and receive SMS and connect to the internet using the GPRS network via UART using AT commands. It supports quad-band and can communicate through GSM 850 MHz, GSM 900 MHz, DCS 1800 MHz or PCS 1900 MHz networks. It has a power jack along with a toggle switch to use an external power supply.

SIM900 shield can be powered by a 5V power supply that can provide 2A current, or 9V 1A or, 12V 1A supply. It is equipped with a microphone and speakers jack for phone calls. At the backside of the shield, there is a sim card jack and a holder for a 3V CR1220 battery for the RTC (real-time clock). After insertion of sim and battery, the shield can be mounted on top of the Arduino board.

Features:

• Compatible with Arduino and its clones
• Quad Band 850 / 900/ 1800 / 1900 MHz GSM network
• Can send and receive SMS, MMS, GPRS and audio using GSM network.
• Supports UART interface
• AT commands
• Embedded TCP/UDP stack facility for uploading data to a web server
• RTC support
• Speaker and Headphone jacks
• Equipped with 12 GPIOs, 2 PWMs, and an ADC

Specifications:

• Supply voltage: 3.4V-4.5V
• Low power consumption: 1.5mA(sleep mode)
• Industrial temperature range: -40⁰C  to +85⁰C
• Class 4 (2 W @ 850 / 900 MHz) , Class 1 (1 W @ 1800 / 1900MHz)
• Dimensions: 8.5 X 5.7 X2cm(approx)