Alright, so you’ve heard of Node.js—the JavaScript runtime that refuses to quit.

But did you know that you can use it to control real-life hardware?

Yep, not just websites and APIs.

We’re talking LEDs, sensors, and even entire smart home setups.

This is the magic of the Internet of Things (IoT)—where devices talk to each other and make us feel like we’re living in a sci-fi movie.

And the best part?

You don’t need to be an embedded systems engineer to get started.

If you know JavaScript, you can hack your way into IoT with Node.js!

🚀 Why Node.js for IoT?

Why use JavaScript for something as serious as hardware?

Because:

• It’s easy – If you know JavaScript, you’re halfway there.
• Event-driven magic – Node.js is built for handling real-time events, perfect for IoT.
• Huge ecosystem – Tons of libraries help you connect sensors, motors, and even your coffee machine to the internet.
• Runs on tiny devices – You can install Node.js on things like the Raspberry Pi.

🛠️ Getting Started: What You Need

Before we get our hands dirty with code, let’s make sure we have the right stuff:

Hardware

• A Raspberry Pi or Arduino (We’ll go with Raspberry Pi since it runs Node.js natively)
• A LED (because no IoT tutorial is complete without blinking something)
• A Resistor (so we don’t fry our poor LED)
• Some wires (yes, you need these)
• A breadboard (optional, but makes life easier)

Software

• Node.js (obviously)
• Johnny-Five (a cool library for working with hardware in JavaScript)
• onoff (for controlling GPIO pins on Raspberry Pi)

🔥 Hello World in IoT: Blinking an LED

If this is your first IoT project, we’re going old school—blinking an LED.

Because nothing says “I built this” like making a tiny light turn on and off.

Step 1: Set Up Node.js on Raspberry Pi

If you haven’t installed Node.js on your Raspberry Pi, do it like this:

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curl -sL https://deb.nodesource.com/setup_16.x | sudo bash -
sudo apt install -y nodejs

Step 2: Install Dependencies

We’ll use the onoff library to control the GPIO pins.

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npm install onoff

Step 3: Wire Up the LED

Connect:

• LED’s long leg (anode) to GPIO pin 17
• Short leg (cathode) to GND
• A 330Ω resistor between GPIO 17 and the LED to avoid magic smoke.

Step 4: Write the Code

Create a file called blink.js:

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const Gpio = require('onoff').Gpio;
const led = new Gpio(17, 'out');

setInterval(() => {
    led.writeSync(led.readSync() ^ 1); // Toggle LED state
    console.log("LED toggled!");
}, 1000);

process.on('SIGINT', () => {
    led.unexport(); // Clean up
    console.log("\nBye bye!");
    process.exit();
});

Step 5: Run It

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node blink.js

Boom! 🎉 Your LED should now be blinking like it’s in a 90s disco.

🌎 IoT + Node.js: Connecting to the Internet

Okay, blinking an LED is cool, but what if you want to control it over the internet?

Let’s make a simple web-controlled LED using Node.js and Express.

Install Express

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npm install express

Write the Server Code

Create server.js:

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const express = require('express');
const Gpio = require('onoff').Gpio;
const app = express();
const led = new Gpio(17, 'out');

app.get('/on', (req, res) => {
    led.writeSync(1);
    res.send('LED is ON');
});

app.get('/off', (req, res) => {
    led.writeSync(0);
    res.send('LED is OFF');
});

app.listen(3000, () => console.log('Server running on http://localhost:3000'));

Run It:

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node server.js

Now open your browser and go to:

• http://localhost:3000/on → LED turns ON
• http://localhost:3000/off → LED turns OFF

Welcome to the future, where even your lightbulbs have an IP address. 🔥

🏡 Taking It Further: IoT Ideas

Now that you’ve got the basics, here are some crazy IoT ideas you can build:

• Smart Doorbell – Detect when someone is at the door and send a notification.
• Temperature Monitor – Use a sensor to measure temperature and send alerts.
• Automated Plant Watering – Water your plants when the soil gets dry.
• IoT Coffee Maker – Brew coffee when you wake up (because waking up is hard).
• Cat Feeder – Feed your cat with the press of a button (or let the cat do it).

🚀 Wrapping Up

Node.js + IoT is a powerful combination that lets you control the world with JavaScript.

Whether it’s turning on an LED or building a full-fledged smart home, the possibilities are endless.

Now go forth, connect everything, and don’t forget to blink some LEDs along the way! ✨

📌 Key Ideas

🔗 References

• Node.js Official Site
• Johnny-Five Library
• onoff Library
• Raspberry Pi GPIO Guide
• Express.js Guide