Project Description:

The GSM Home Automation Hub is a smart home system that allows users to control electrical appliances remotely via SMS commands using GSM (Global System for Mobile communication) technology. This project is especially useful in rural or low-internet areas where GSM signals are more reliable than Wi-Fi or internet connections.

Technologies Used:

• Backend: Node.js / PHP / Java (for dashboard or logging interface)

• Frontend: HTML, CSS, Bootstrap, JavaScript (optional for admin panel)

• Microcontroller: Arduino / ESP32 with GSM Module (SIM800L/SIM900)

• Communication: GSM-based SMS commands

• Relays: To switch devices (lights, fans, etc.)

• Database (optional): MySQL for command logs and status tracking

Key Features:

1. SMS-Based Appliance Control:

   • Users send predefined SMS commands (e.g., "LIGHT ON", "FAN OFF") to a GSM module.

   • The system interprets the commands and switches the relevant device accordingly.

2. Appliance Status Feedback:

   • The system can reply with confirmation SMS (e.g., "Light turned ON") for user assurance.

3. Multi-Device Support:

   • Can control multiple appliances like lights, fans, heaters, etc.

4. Security Features:

   • Accepts SMS commands only from registered numbers.

   • Logs unauthorized attempts.

5. Manual Override:

   • Local switches still functional in case of GSM failure.

6. Optional Web Dashboard:

   • A basic interface to view SMS logs, device history, and control status.

System Workflow:

1. User sends SMS command to the SIM card installed in the GSM module.

2. The GSM module forwards the command to the microcontroller.

3. The microcontroller parses the command and triggers corresponding relays.

4. Appliances switch ON/OFF accordingly.

5. A feedback SMS is sent back to the user.