With a tiny size, it can fit into slim and compact demands of custom design. Featuring and Embedded AT, it allows total cost savings and fast time-to-market for customer applications.

The SIM800A modem has a SIM800A GSM chip and RS232 interface while enables easy connection with the computer or laptop using the USB to the Serial connector or to the micro-controller using the RS232 to TTL converter. Once you connect the SIM800A modem using the USB to RS232 connector, you need to find the correct COM port from the Device Manager of the USB to Serial Adapter.

Then you can open Putty or any other terminal software and open a connection to that COM port at 9600 baud rate, which is the default baud rate of this modem. Once a serial connection is open through the computer or your micro-controller you can start sending the AT commands. When you send AT commands for example “AT\r” you should receive back a reply from the SIM800A modem saying “OK” or other response depending on the command sent.

Features and Specifications of SIM800A Module :-

• SIM800A Quad Band GSM Module
  
• Bands: GSM 850MHz, EGSM 900MHz, DCS 1800MHz, PCS 1900MHz
  
• Coding schemes: CS-1, CS-2, CS-3, CS-4 Tx power: Class 4 (2W), Class 1 (1W)
  
• GPRS class 2/10.
  
• Control via AT commands (3GPP TS 27.007, 27.005 and SIMCOM enhanced AT command set).
  
• Voltage Supply Required- 9VDC to 12VDC with atleast 2A Peak Current Capability
  
• High-Quality Product (Not hobby grade).
  
• 5V interface for direct communication with MCU kit.
  
• TTL Rx and TTL Tx and DB9 Connector Based RS232 Outputs
  
• Configurable baud rate.
  
• Built-in SIM Card holder.
  
• Built-in Network Status LED.
  
• Inbuilt Powerful TCP/IP protocol stack for internet data transfer over GPRS.
  
• Low power.
  
• Operating temperature: -40C to +85C
  
• External Finger type antenna
• Weight - 40gm

Applications :- 

• Remote Data Monitor and Control.
  
• Water, gas and oil flow metering.
  
• AMR (automatic meter reading).
  
• Power station monitoring and control.
  
• Remote POS (point of sale) terminals.
  
• Traffic signals monitor and control.
  
• Fleet management.
  
• Power distribution network supervision.
  
• Central heating system supervision.
  
• Weather station data transmission.
  
• Hydro-logic data acquisition.
  
• Vending machine.
  
• Traffic info guidance.
  
• Parking meter and Taxi Monitor.
  
• Telecom equipment supervision (Mobile base station, microwave or optical relay station).