GSM MODEM SIM900A WITH TTL RS232 OUTPUT COMPATIBLE TO IN INDIA

  This is a plug and play GSM Modem with a simple to implement RS232, TTL serial and USB interface. It works on frequencies 900/ 1800 MHz. Use it to send SMS, make and receive calls, and do other GSM operations by simple AT commands through a serial interface from microcontrollers and computers. It uses the popular SIM900A module for all its GSM operations. It comes with a standard RS232 interface which can be used to easily interface the modem to microcontrollers and computers. Through USB, the modem can be operated from a computer to send/receive calls, messages, etc    The modem consists of all the external circuit required to start experimenting with the SIM900A module like the power regulation, external antenna, SIM Holder, etc. Features Uses the extremely popular SIM900A GSM module USB communication allows direct communication with computers 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, Status and Network LEDs for easy debugging Onboard MIC and Speaker circuits and 3.5mm audio connectors for direct connection to mics and speakers 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 Key connected to the PWRKEY pin (refer the SIM900A 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 SIM900A allows an adjustable serial baudrate from 1200 to 115200 bps Modem has 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) Related Documents Stater Guide AT Commands Set   Download Terminal tool for Troubleshooting(winXP/7/8)