SIM900A Mini Module 5V – Dual-Band 900/1800MHz GSM/GPRS Module with SMS, Voice & AT Commands

The SIM900A Mini Module 5V provides GSM/GPRS connectivity in a compact development-board format. The underlying SIM900A module is designed for 900MHz and 1800MHz GSM networks and supports voice, SMS, GPRS data, and AT-command-based control.

Its integrated GPRS functionality and TCP/IP support make it useful for applications where a microcontroller needs to exchange small amounts of data over a cellular network. The configurable UART interface also makes it suitable for serial communication with embedded controllers.

The development-board version provides convenient power and communication connections and can be integrated into projects involving remote monitoring, alarms, tracking, SMS control, and telemetry.

Features

• SIMCom SIM900A GSM/GPRS module
• Dual-band 900MHz / 1800MHz operation
• GPRS multi-slot Class 10/8
• GSM Phase 2/2+ compatible
• Supports SMS communication
• Supports voice communication
• Integrated TCP/IP functionality
• AT-command control
• GSM 07.07 and GSM 07.05 command support
• SIMCom enhanced AT commands
• Configurable 1200–115200bps serial communication
• Low-power sleep operation
• TTL serial and RS232 interface options on supported board versions
• SMA/IPX antenna connection options depending on board revision
• Suitable for Arduino and microcontroller projects

Applications

• SMS notification systems
• Remote alarm systems
• GSM-controlled automation
• Vehicle and asset monitoring
• Remote telemetry
• Industrial equipment monitoring
• GPRS data logging
• Environmental monitoring
• Remote sensor systems
• Arduino GSM projects
• Cellular communication experiments
• Embedded GSM/GPRS development

How to Use

1. Insert a compatible SIM card into the board.
2. Connect a suitable GSM antenna before activating the cellular radio.
3. Provide the correct power input for the particular board revision.
4. Connect the UART interface to the microcontroller or USB-to-serial adapter.
5. Open a serial terminal using the appropriate baud rate.
6. Test communication using basic AT commands such as AT.
7. Check SIM and network registration status.
8. Configure SMS, voice, or GPRS functions using the required AT commands.
9. For GPRS applications, configure the carrier APN and required TCP/IP settings.
10. If the module is supplied with a country/region-specific firmware configuration, firmware/network configuration may need to be adjusted for the intended operating region.

Important Notes

• SIM900A is a 2G GSM/GPRS module supporting 900MHz and 1800MHz. Verify that 2G service on these bands is available from your local mobile operator before purchase.
• This product is intended for advanced users familiar with GSM modules, AT commands, serial communication, and microcontroller programming.
• The exact power requirements depend on the development-board revision. Do not assume that every board pin accepts 5V directly; verify the labels and documentation of the supplied board.
• GSM transmission can produce short-duration current peaks, so the supply should be stable and adequately rated.
• Use a suitable external power source rather than relying on a weak microcontroller 5V rail.
• Connect GND between the GSM module and microcontroller when using UART communication.
• Do not insert or remove the SIM card while the board is powered.
• A suitable antenna should be connected before normal GSM operation.
• Network registration depends on SIM status, carrier support, signal strength, antenna installation, and local 2G availability.
• The module's country/region configuration may require appropriate firmware or network configuration before use.
• Product dimensions and board layout can vary slightly between production revisions.
• Please allow approximately 5% measuring deviation for manual measurements.
• Product images are for illustration only; actual PCB components, connectors, antenna type, and board markings may vary.

Package Includes

• 1 × SIM900A Mini Board Module Core Unit
• 1 × Snap-Fit Cellular Rod Antenna
• 1 × Power Jumper Harness