GSM Modem

This is a plug and play GSM Modem with a simple to interface serial interface. Use it to send SMS, make and receive calls, and do other GSM operations by controlling it through simple AT commands from micro controllers and computers. It uses the highly popular SIM300 module for all its operations. It comes with a standard RS232 interface which can be used to easily interface the modem to micro controllers and computers.
The modem consists of all the required external circuitry required to start experimenting with the SIM300 module like the power regulation, external antenna, SIM Holder, etc.
Features
Uses the extremely popular SIM300 GSM module
Provides the industry standard serial RS232 interface for easy connection to computers and other devices
Provides serial TTL interface for easy and direct interface to microcontrollers
Power, RING and Network LEDs for easy debugging
Onboard 3V Lithium Battery holder with appropriate circuitry for providing backup for the modules’ internal RTC
Can be used for GSM based Voice communications, Data/Fax, SMS,GPRS and TCP/IP stack
Can be controlled through standard AT commands
Module’s operation mode can be controlled through the PWR Switch connected to the PWR pin (refer the SIM300 datasheet for more information)
Comes with an onboard wire antenna for better reception. Board provides an option for adding an external antenna through an SMA connector
The SIM300 allows an adjustable serial baud rate from 1200 to 115200 bps (9600 default)
Modem a low power consumption of 0.25 A during normal operations and around 1 A during transmission
Operating Voltage: 7 – 15V AC or DC (board has onboard rectifier)
Note: The modem consumes current of nearly 1A during transmission; please make sure that your power supply can handle such currents.