SIM900A GSM GPRS Board Module 5V with Antenna

Product Description

The SIM900A GSM/GPRS Module with Antenna is a compact and versatile wireless communication module designed for adding 2G GSM/GPRS connectivity to embedded systems, Arduino projects, microcontroller applications, and IoT prototypes. It provides a convenient way to send and receive SMS messages, make calls, and communicate with remote servers through a compatible SIM card and cellular network.

The module supports flexible power options, allowing operation through 5V VCC5 input or a lower 3.5–4.5V VCC4 supply, depending on the selected power configuration. It also includes options for power-on self-starting or controlled startup.

For wireless connectivity, the board provides an SMA antenna interface as the default antenna connection and also includes an IPXmini antenna interface option. The SIM900A interface includes a dedicated reset function for convenient module control.

The module features a compact PCB measuring approximately 49 × 47 mm and includes clearly marked connection points for power, serial communication, reset, and antenna interfaces. Its TTL serial interface can be connected to 3.3V or 5V microcontrollers, making it suitable for a wide range of development platforms.

An onboard SIM card circuit with ESD protection helps protect the SIM interface, while the serial interface includes protection circuitry for improved reliability. The board also provides speech and microphone interfaces for GSM voice communication applications.

Please note that depending on stock availability, you may receive the V4.0 or 3.5++ version. There is no functional difference between these versions for the intended applications.

Features

• SIM900A GSM/GPRS wireless communication module
• Supports 2G GSM/GPRS cellular connectivity
• Compatible with suitable 2G SIM cards
• Can work with compatible 3G/4G SIM cards where 2G service is available
• Supports SMS communication
• Supports GSM voice calling applications
• GPRS data communication capability
• Dual power supply options
• VCC5 input for 5V power supply
• VCC4 input for approximately 3.5–4.5V supply
• Supports power-on self-starting
• Supports controlled power startup
• SMA antenna interface
• IPXmini antenna interface
• TTL-level serial communication
• Compatible with 3.3V and 5V microcontrollers
• Onboard SIM card slot
• SIM interface with SMF05C ESD protection
• Onboard reset control
• Speech and microphone interfaces
• Protected serial interface circuit
• Clearly labelled PCB interfaces
• Four mounting holes
• Compact and lightweight design
• Suitable for Arduino and embedded projects
• Useful for IoT and remote communication projects

Specifications

*Actual current consumption depends on network conditions, operating mode, supply, and connected peripherals.

Control Interface Pin Description

The TTL serial interface allows the module to communicate with a microcontroller or development board through UART communication. Appropriate voltage-level considerations should be followed when connecting the module to other electronics.

Design and Construction

The SIM900A module is built on a compact PCB designed to provide convenient access to the module’s communication and control functions. The board has clearly marked interfaces for power supply, serial communication, reset, SIM card, and antenna connections.

The onboard SIM card slot provides convenient access for inserting a compatible SIM card. An SMF05C ESD protection device is included in the SIM interface circuit to provide additional protection against electrostatic discharge.

Four 3.5 mm mounting holes are provided at the corners of the PCB, allowing the module to be securely mounted inside enclosures, robotics platforms, development systems, and other projects.

The board also includes an SMA antenna interface and an alternative IPXmini interface, providing flexibility when selecting an antenna suitable for the installation.

Working Principle

The SIM900A module communicates with a cellular network using GSM/GPRS technology. A compatible SIM card is inserted into the onboard SIM slot, and an appropriate GSM antenna is connected to the antenna interface.

A microcontroller or computer communicates with the module through its TTL UART serial interface. Commands can be sent to the module to perform functions such as network registration, SMS transmission, voice calls, and GPRS data communication.

For example, a microcontroller can send AT commands through the serial interface to control the SIM900A. The module processes these commands and communicates with the cellular network to perform the requested operation.

The module can therefore act as a wireless communication interface between an embedded system and a cellular network.

Applications

• Arduino GSM projects
• IoT prototypes
• GSM-based automation
• Remote monitoring systems
• SMS alert systems
• GSM-controlled devices
• Remote switching applications
• GPS/GSM tracking systems
• Security and alarm systems
• Smart agriculture projects
• Industrial monitoring
• Remote data transmission
• GPRS-based IoT projects
• Embedded communication systems
• Wireless sensor networks
• Home automation
• Vehicle tracking projects
• GSM voice communication projects
• SMS-based control systems
• Educational electronics projects

Power Supply

The module provides two power input options:

• VCC5: Intended for a 5V supply.
• VCC4: Intended for approximately 3.5–4.5V supply.

Use the appropriate power input according to the board’s configuration and avoid applying incompatible voltage levels. GSM modules can experience short-duration current peaks during network transmission, so the power source should be capable of supplying the required current without significant voltage drop.

SIM Card Compatibility

The module is designed for GSM/GPRS cellular communication and requires a compatible SIM card with network support for 2G service.

A 3G or 4G SIM card may work if the mobile network and SIM provisioning still provide compatible 2G GSM service in the operating area. Network availability varies by operator and location, so verify 2G support before purchasing or deploying the module.

Version Information

Depending on stock availability, the product may be supplied as V4.0 or 3.5++.

Both versions are intended for the same type of SIM900A GSM/GPRS applications, and there is no functional difference for the stated use cases.

Package Includes

• 1 × SIM900A GSM/GPRS Module
• 1 × Power Cable
• 1 × GSM Antenna

Product Disclaimer

Product images are for representation purposes only. The actual product may vary slightly in PCB colour, component placement, connector appearance, labelling, or physical appearance depending on the manufacturing batch.

The module requires a compatible SIM card and cellular network service, which are not included.

GSM/GPRS functionality depends on the availability of compatible 2G network service in your location. Network operators may have different coverage, frequency, SIM, and service requirements.

Please use an appropriate power supply and antenna and follow correct wiring and voltage requirements during installation.

The product may be supplied as V4.0 or 3.5++ depending on stock availability. Both versions are considered equivalent for the intended applications.