SIM900A Mini GSM GPRS Module

This SIM900A Mini GSM/GPRS Module brings cellular connectivity to your microcontroller projects, letting you send SMS messages, make voice calls, and transfer data over a standard GSM network. Built around the widely used SIMCom SIM900A chipset, this dual-band module is compact, affordable, and simple to interface with popular development boards, making it a favorite among Arduino, ESP32, and Raspberry Pi hobbyists building IoT devices, remote alert systems, GPS trackers, and home automation projects. The board features both TTL and RS232 level serial interfaces, so it connects directly to most microcontrollers without extra level-shifting circuitry, and communication is handled through simple, well-documented AT commands. A standard SIM card slot lets you use any local GSM network SIM, while onboard status and network LEDs make it easy to monitor connection state at a glance. Note that GSM modules draw significant current spikes during transmission, so a stable, adequately rated power supply is essential for reliable operation; using a weak or unregulated source is a common cause of failed network registration. Lightweight, beginner-friendly, and well supported by community libraries, this module is an excellent starting point for anyone looking to add SMS or call functionality to their next embedded electronics build.

Specification:

• Chipset : SIMCom SIM900A
• Frequency Bands : Dual-Band EGSM900 & DCS1800 MHz
• GPRS : Multi-slot Class 10, CS-1 to CS-4
• Power Supply : 4.6V – 5.2V DC
• Operating Current : 1A minimum, peak up to 2A
• Interface : TTL & RS232 Serial (UART)
• Communication : AT Commands
• SIM Card Support : Standard SIM Card