Creating flowing LEDs (also known as a "running light" or "LED chaser") with Raspberry Pi and Node.js is a classic and fun electronics project! 💡💡💡 Let’s set it up step by step using the onoff library.

🧰 What You Need

• Raspberry Pi (any model with GPIO)

• 4–8 LEDs

• Resistors (330Ω for each LED)

• Breadboard + jumper wires

🔌 GPIO Pin Setup Example

You can extend this with more LEDs too.

📦 Step 1: Install onoff

bash
npm init -ynpm install onoff

💡 Step 2: Create flowing-leds.js

js
const leds = [  new Gpio(17, 'out'),  // LED1  new Gpio(18, 'out'),  // LED2  new Gpio(27, 'out'),  // LED3  new Gpio(22, 'out')   // LED4];let index = 0;const delay = 200; // milliseconds between stepsconst interval = setInterval(() => {  leds.forEach((led, i) => led.led => {    led.writeSync(0);    led.unexport();  });  console.log('\nFlowing LEDs stopped.');  process.exit();});

🚀 Step 3: Run It

bash
sudo node flowing-leds.js

Use sudo because GPIO access requires root privileges.

🧠 Bonus Ideas

• Reverse the flow: run backward after reaching the end

• Flow back and forth like Knight Rider

• Add a button to control speed or direction

• Use PWM for fade-in/out effect (with pigpio)