SIM900A Modem is built with Dual Band GSM based SIM900A modem from SIMCOM. It works on frequencies 900MHz. SIM900A can search these two bands automatically. The frequency bands can also be set by AT Commands. The baud rate is configurable from 1200-115200 through AT command. SIM900A is an ultra compact and wireless module. The Modem is coming interface, which allows you connect PC as well as microcontroller with RS232 Chip(MAX232). It is suitable for SMS, Voice as well as DATA transfer application in M2M interface. The onboard Regulated Power supply allows you to connect wide range unregulated power supply. Using this modem, you can make audio calls, SMS, Read SMS, attend the incoming calls and ect. through simple AT commands. This is a complete GSM module in a SMT type and made with a very powerful single-chip, allowing you to benefit from small dimensions. SIM 900A GSM Modem with serial and TTL outputs. 

Features:-

• Quad-Band GSM/ 850/900/1800/1900MHz
  
• Compatible with arduino, raspberry pi, arm, avr, pic, 8051
  
• power supply 12v 1amp to 2 amps max
  
• Use in the area of full signal strength.
  
• Perfect suited for GSM based Microcontroller Projects (better than SIM300 and other GSM Modems)
  
• Option for connecting MIC and SPEAKER directly to GSM MODEM for calls (LINE IN also available)
  
• Supports communication through RS232 with DB9 Connector, TTL Pins and I2C Pins
  
• CALL SMS GPRS facility - MIC input, LINE input and SPEAKER output pins

Package Includes:-

• 1x SIM900 850/900/1800/1900 MHz GSM Development Board Module 
  
• 1x SMA Antenna