SIM900A is a complete GSM/GPRS solution in a LGA type which can be embedded in the customer applications. SIM900a support Quad-band 850/900/1800/1900MHz, it can transmit Voice, SMS and data information with low power consumption. Featuring and Embedded AT, it allows total cost savings and fast time-to-market for customer applications.
The SIM900A modem has a SIM900A GSM chip and RS232 interface while enables easy connection with the computer or laptop using the USB to Serial connector or to the microcontroller using the RS232 to TTL converter. Once you connect the SIM900 modem using the USB to RS232 connector, you need to find the correct COM port from the Device Manger of the USB to Serial Adapter. Then you can open Putty or any other terminal software and open an 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 microcontroller you can start sending the AT commands. When you send AT commands for example: “AT\r” you should receive back a reply from the SIM900A modem saying “OK” or other response depending on the command send.
• Quad band 850/900/1800/1900MHz
• GPRS class 2/10
• Control via AT commands (3GPP TS 27.007, 27.005 and SIMCOM enhanced AT commandset)
• Supply voltage 3.4-4.4V
• Low power
• Operating temperature -40+85C