SIM900A GSM GPRS Module

The SIM900A modem is a dual-band GSM-based device from SIMCOM, designed to operate on the 900MHz frequency band. It can automatically search for these frequency bands, but they can also be manually configured using AT commands. With a configurable baud rate ranging from 1200 to 115200 via AT commands, the SIM900A is an ultra-compact wireless module ideal for various applications. Its interface allows for easy connection to both PCs and microcontrollers through an RS232 chip (MAX232), making it suitable for SMS, voice, and data transfer in M2M (Machine-to-Machine) communication. The onboard regulated power supply supports a wide range of unregulated power inputs. With this modem, users can make and receive audio calls, send and read SMS messages, and manage incoming calls, all through simple AT commands. Its SMT design and powerful single-chip construction make it a compact yet complete GSM module, with serial and TTL output options for versatile connectivity.