SIM900A GSM GPRS Module with RS232 Interface and SMA Antenna

SIM900A GSM GPRS Module with RS232 Interface and SMA Antenna provides a reliable and cost-effective solution for adding cellular connectivity to embedded systems and industrial equipment. This dual-band module enables your devices to send SMS messages, make voice calls, and transmit GPRS data over the GSM network. Consequently, it serves as a bridge between remote hardware and the global telecommunications infrastructure. The integrated RS232 interface allows for direct communication with PCs and industrial PLCs without the need for additional level converters. Furthermore, the inclusion of an SMA antenna connector ensures that you can achieve stable signal reception even in challenging environments. Therefore, you can quickly deploy this module in M2M (Machine to Machine) projects to monitor and control assets remotely from anywhere in the world.

Key Features:

• Dual-Band Connectivity: Operates on 900 MHz and 1800 MHz frequencies, ensuring compatibility with major cellular providers across Asia and Europe.
• Integrated RS232 Port: Features a standard DB9 or header-based RS232 interface, which simplifies the connection to legacy systems and industrial controllers.
• SMA Antenna Support: Includes a high-gain SMA antenna that you can easily mount or replace to optimize signal strength in low-coverage areas.
• GPRS Multi-slot Class: Supports GPRS multi-slot class 10/8, enabling efficient data transfer for IoT and remote telemetry applications.
• AT Command Control: Responds to standard industrial AT commands, allowing for straightforward programming through any serial terminal or microcontroller.

Technical Specifications:

• Operating Voltage: 5 V to 12 V DC (typically via an external power adapter)
• Peak Current: 2 A (during transmission bursts)
• Frequencies: Dual-band 900/1800 MHz
• GPRS Data Speed: Max 85.6 kbps (Download/Upload)
• Communication Interface: RS232 (Serial) and TTL Logic Level (optional headers)
• SIM Card Slot: Standard size (1.8 V / 3.0 V)
• Operating Temperature: −40°C to +85°C

Mechanical Specifications:

• Board Material: High-grade FR4 PCB with green solder mask
• Mounting Holes: 4 x M3 sized holes for secure industrial mounting
• Antenna Connector: SMA Female
• Interface Connector: RS232 DB9 Female / 2.54 mm Pitch Headers

Dimensions:

• Module Length: ≈ 80 mm
• Module Width: ≈ 55 mm
• Total Height (with connectors): ≈ 15 mm
• Weight: ≈ 65 g (including antenna)

Pinout and Wiring:

• VCC / DC Jack: Connect to a stable power source capable of delivering at least 2 A.
• GND: Common ground connection for the power supply and serial data.
• RS232 DB9: Connect directly to a PC COM port or a USB-to-Serial converter for initial testing.
• TX/RX (TTL): Connect these pins to the UART pins of your microcontroller if you are not using the RS232 interface.
• SIM Slot: Insert a valid 2G-compatible SIM card here before powering the device.
• Status LED: Indicates the network registration status; a slow blink usually means a successful network connection.

Datasheet Reference:

• Download SIM900A GSM Module Datasheet

Commonly Used in:

• Industrial Telemetry: Transmitting sensor data from remote stations to a central server via GPRS.
• SMS Alert Systems: Sending automated text notifications from fire alarms, security panels, or environmental monitors.
• Vehicle Tracking: Acting as the communication core for GPS-based fleet management systems.

Applications:

• Remote Meter Reading: Automating the collection of electricity or water meter data over the cellular network.
• Smart Agriculture: Monitoring soil moisture and controlling irrigation pumps via SMS commands.
• Security Systems: Providing a wireless backup for alarm systems if the primary landline or internet connection fails.

Equivalent Models:

• SIM800L: A more compact module, however, it typically lacks the built-in RS232 interface.
• SIM900: The quad-band version of this module, which works globally including in North American frequencies.
• Quectel M95: A functionally similar GSM/GPRS transceiver often used as a direct alternative in industrial designs.

Package Includes:

• 1 x SIM900A GSM GPRS Module with RS232 Interface
• 1 x SMA Male GSM Antenna