Wiznet makers

As smart home technology becomes more common, the ability to control lights and appliances from a smartphone or PC is no longer futuristic. Commercial IoT solutions exist, but they often require complex setups or costly devices.

This project demonstrates that with just a few affordable components and simple code, anyone can build a web-controlled smart switch. Using an Arduino, an Ethernet Shield, and a relay module, you can transform a conventional switch into a network-enabled remote control system.

Core Idea

The concept is straightforward:

1. The Arduino runs a web server through the Ethernet Shield.
2. A user connects to the device’s IP address from a browser within the same network.
3. The browser displays an HTML page with ON/OFF buttons.
4. Clicking a button sends an HTTP request to the Arduino.
5. The Arduino processes the request and toggles the relay, switching the connected device on or off.

With this setup, a simple electrical switch becomes a basic IoT smart switch.

Hardware Components

• Arduino UNO (or compatible board) – the main controller.
• Ethernet Shield (W5100-based) – provides network connectivity.
• Relay Module – switches electrical loads safely.
• Power Supply – ensures stable operation.

This minimal hardware combination is sufficient to build a fully functional prototype.

How It Works

1. On startup, the Arduino configures the Ethernet Shield with a static IP address and launches a lightweight web server.
2. A client (PC or smartphone) connects to the IP and receives a simple HTML control page.
3. The HTML page provides ON/OFF buttons; pressing one sends an HTTP GET request.
4. The Arduino parses the request and sets the relay control pin HIGH or LOW.
5. The relay switches the connected electrical load accordingly.

Benefits

• Educational Value – introduces concepts of networking, web servers, and hardware control in a single project.
• Practical Use – enables remote control of appliances such as lamps or fans on a local network.
• Scalability – serves as a foundation for advanced IoT systems, such as automation with sensors.

Limitations and Improvements

While the project is simple and effective, there are limitations:

• Security – no authentication or encryption; any device on the same network can access it.
  • Improvement: Add password protection, HTTPS, or use MQTT with TLS.
• Functionality – currently controls a single relay.
  • Improvement: Expand to multi-relay control, add status indicators, or logging.
• Hardware Constraints – the W5100 chip has limited socket connections.
  • Improvement: Use the W5500 Ethernet chip for better performance.

Conclusion

This project is more than a simple tutorial—it is a gateway into IoT development. With Arduino, an Ethernet Shield, and a relay, you can experience the excitement of controlling real-world devices through a browser.

It provides a practical introduction to web-based device control, IoT basics, and smart home applications. With further refinements in security and scalability, this small project can evolve into a powerful smart home automation system.