A lightweight Arduino library for controlling the AiThinker A9G module, which provides GPRS, GPS, and SMS functionality. It offers two core classes:

1. A9G
   Handles low-level AT commands (e.g., sending SMS, GPRS/APN setup, enabling GPS, simple MQTT commands).

2. A9Gmod
   A higher-level interface that simplifies MQTT usage, similar to other Arduino MQTT clients.

• Initialization & Basic Checks

  • Ensure module responsiveness (send AT command).
  • Check device IMEI, signal quality, and SIM CCID.
  • Wait for the module to report a READY status.

• GPRS & APN Configuration

  • Attach/detach GPRS connectivity.
  • Set APN parameters.
  • Activate/deactivate PDP context for data usage.

• GPS

  • Enable/disable onboard GPS and AGPS.
  • Fetch raw GPS NMEA sentences for parsing.

• SMS

  • Send, read, and delete SMS in text mode.
  • Configure SMS storage.

• MQTT

  • Connect to MQTT brokers with optional username/password credentials.
  • Publish and subscribe to topics with customizable QoS settings.
  • Register callbacks to receive incoming MQTT messages.

1. Place Library
   Copy the library files into a folder named A9Gmod under your Arduino libraries directory.

2. Include in Sketch
   Add an include statement for the library in your Arduino code.

3. Compile & Upload
   Verify that your board and port settings are correct, then compile and upload your sketch.

1. Create an A9G instance for sending AT commands to the A9G module.
2. Initialize the module by pointing to a serial interface.
3. Set APN & GPRS if network connectivity is required.
4. Use A9Gmod if you want a high-level approach for MQTT.
5. Poll the modem in your main loop to handle events and incoming data.

Manages direct AT command communication, exposing methods to:

• Configure GPRS and APN.
• Enable/disable GPS and read GPS data.
• Send and receive SMS.
• Connect to an MQTT broker at a lower level.

Provides a simplified MQTT client interface:

• Define the broker address and port.
• Connect using client ID, username, and password if needed.
• Publish, subscribe, unsubscribe, and disconnect easily.
• Register a callback to handle incoming messages.

• SMS Example
  Demonstrates how to send and read text messages.
• GPS Example
  Shows how to enable GPS and retrieve NMEA sentences.
• MQTT Example
  Illustrates connecting to a public broker and handling publish/subscribe operations.

Contributions are welcome! Feel free to open issues for bug reports or feature requests, and submit pull requests with improvements or examples.

Check the License file for in-depth idea of usage.

Author:
@MD. Touhiduzzaman Turja (Zaman Turja)

For questions, suggestions, or any help, please reach out or create an issue in the repository.