Smart Lab Web of Things (WoT)

This project implements a Web of Things (WoT) environment simulating a smart laboratory. It consists of three interconnected virtual devices: a Lamp, a Motion Sensor, and a Thermostat.

The system is built on a distributed architecture where each device operates as an independent web service. A central Gateway manages the device registry, user authentication, and real-time event propagation. Interaction is handled via RESTful interfaces and WebSockets for event-driven communication.

🚀 Features

• Microservice Architecture: Each device (Lamp, Thermostat, Sensor) is an independent Node.js service.
• Discovery and Registration: Devices automatically register with the gateway on startup using a secure "System Token".
• Real-Time Dashboard: A web interface connects via Socket.IO to receive live status updates and control the devices.
• Secure Authentication: Token-based authentication system for users, with password hashing (bcrypt).
• Rule Engine: A central service on the gateway applies automation rules based on device states.
• Event Logging: All actions (connections, manual actions, state changes) are logged to the MongoDB database.
• Physical Simulation: The thermostat actively simulates temperature changes based on its current mode and target.

🏗️ System Architecture

The system is composed of the following services, each running on a separate port:

• Gateway: http://localhost:3000

  • Central coordination point.
  • Manages the device registry, authentication (users and system), and the Socket.IO server.
  • Hosts the rule engine.

• Lamp Service: http://localhost:3001

  • Exposes actions (turnOn, turnOff, setColor, setBrightness) and properties (on, color, brightness).

• Thermostat Service: http://localhost:3002

  • Exposes actions (setMode, setTarget) and properties (currentTemperature, targetTemperature, mode).
  • Simulates its own temperature.

• Motion Sensor Service: http://localhost:3003

  • Exposes the action (simulateMotion) and properties (motion, lastDetected).

• Database: mongodb://localhost:27017/smartlab

  • Stores users and event logs.

• Dashboard (Client)

  • Web interface (HTML, CSS, JS) for user interaction.

🛠️ Tech Stack

• Backend: Node.js
• Framework: Express.js
• Real-time Communication: Socket.IO
• Database: MongoDB with Mongoose
• Frontend: Vanilla JavaScript (ES6+), HTML5, CSS3
• Security: bcrypt hashing, Custom authentication tokens.

⚙️ Installation and Launch

Prerequisites

• Node.js (v18+)
• npm (or yarn)
• MongoDB (local server running)

Installation Steps

1. Clone the repository (if applicable)

   git clone [YOUR_REPO_URL]
   cd [YOUR_PROJECT_FOLDER]

2. Install dependencies (Assuming a package.json exists at the root or in each service folder)

   npm install

   Note: You may need to run this in each service folder (gateway, services/lamp, etc.) if dependencies are managed separately.

3. Start the database Ensure your MongoDB service is running on the default port (27017).

4. Start the services (Order is Important!)

   You must start the Gateway first. On its first launch, it creates the system user and generates a SYSTEM_TOKEN in a .env file at the root. The other services need this token to register.

   Open 4 separate terminals:

   • Terminal 1: Gateway

     # Option 1: Using node
     node gateway/index.js
     # Option 2: Using npm script
     npm run dev 
     
     # Wait to see: "Gateway on :3000" and "SYSTEM_TOKEN saved to .env"

   • Terminal 2: Lamp Service

     # Option 1: Using node
     node services/lamp/app.js
     # Option 2: Using npm script
     npm run dev 
     
     # Should display: "Lamp registered with ID: lamp-..."

   • Terminal 3: Thermostat Service

     # Option 1: Using node
     node services/thermostat/app.js
     # Option 2: Using npm script
     npm run dev 
     
     # Should display: "Thermostat registered with ID: thermostat-..."

   • Terminal 4: Motion Sensor Service

     # Option 1: Using node
     node services/motion/app.js
     # Option 2: Using npm script
     npm run dev 
     
     # Should display: "Motion Sensor registered with ID: motion-..."

   (Note: Adjust paths like gateway/index.js based on your project structure. npm run dev assumes you have a dev script defined in the package.json of each service.)

5. Access the Dashboard Open the dashboard/index.html file in your browser. You can use a browser extension like "Live Server" in VS Code to serve it locally.

🧠 Automation Rules (Implemented)

The Rule Engine (RuleEngine.js) applies the following logic (based on the source code):

1. Light on Detection

   • If: motion is detected (becomes true) AND the lamp is off.
   • Then: The lamp turns on (turnOn).
   • And: The lamp turns off (turnOff) automatically after 2 seconds.

2. Comfort Heating

   • If: The thermostat's currentTemperature is < 18°C AND motion is active.
   • Then: The thermostat switches to comfort mode.

3. Energy Saving (Inactivity)

   • If: 5 minutes have passed since the lastDetected motion.
   • Then: The lamp turns off (turnOff) AND the thermostat switches to eco mode.
   • (This rule is checked every 30 seconds).

4. Manual Override

   • If: A user manually changes the thermostat mode (mode: 'manual').
   • Then: All automation rules (above) are suspended for 30 seconds to respect the user's intent.