GSM/GPRS SIM900 Shield for Arduino

It supports Quad-Band GSM 850/900/1800/1900 MHz networks, so it works worldwide. Thanks to the built-in TCP/UDP stack, you can send data to remote servers for IoT, telemetry and remote control applications.

The serial interface uses standard AT commands (GSM 07.07 & 07.05) plus the extended SIMCOM set, giving you full control of the network functions. The module has headphone and microphone jacks, which makes it perfect for voice communication projects too.

The shield also has a slot for a CR1220 battery (not included), needed to keep the Real Time Clock (RTC) running, hold the time and keep everything in sync even when the main power is off.

IMPORTANT! A SIM card (not included) is required, giving access to the GSM network to make calls, send SMS messages and connect to the Internet over GPRS.

• AT commands: supports the standard AT commands (GSM 07.07, 07.05) and the extended SIMCOM commands to send SMS messages, make voice calls and connect to the Internet over GPRS.
• Arduino compatibility: works with the Arduino UNO, with serial communication over pins D0 (TX) and D1 (RX), or over pins D7 and D8 for a software serial port.
• Easy to fit: just put a SIM in the slot and plug the shield onto the Arduino to start using it. It can also be used with the Arduino MEGA by wiring pins D7 and D8 to pins RX1 and TX1.
• Power options: powered from the Arduino or from an external source (5V-12V DC, at least 1A). The power source is selected with a switch on the shield.
• Power-up control: you can switch the shield on with the pushbutton on the board or in software using pin D9.
• Antenna connector: the shield has an SMA connector for an external antenna, handy for improving GSM/GPRS reception and transmission. (SMA antenna included).

• Transmit power:
  • Class 4 (2W) @ 850/900 MHz.
  • Class 1 (1W) @ 1800/1900 MHz.
• SMS support: send and receive in ASCII and HEX format.
• 3.5 mm audio jacks: for headphones and microphone.