How to Build a 5-LED Chaser Using Arduino (Complete Guide)

Introduction

An LED chaser is one of the most popular beginner Arduino projects. In this project, multiple LEDs turn ON and OFF one after another in a sequence, creating a “running light” or “chasing” effect.

This project helps you understand:

• Digital output pins
• Basic electronics (LEDs & resistors)
• Arduino programming (pinMode, digitalWrite, delay)

It’s perfect for school projects, electronics beginners, and IoT learners.

Project Objective

To design and program an Arduino circuit where 5 LEDs glow one by one in sequence, creating a chaser effect.

Components Required

Circuit Diagram

The following diagram shows how the 5 LEDs are connected to the Arduino Uno using current-limiting resistors.

Circuit Diagram Explanation

Each LED is connected to one Arduino digital pin through a resistor.

Connections:

• LED Anode (+) → Arduino Digital Pin
• LED Cathode (–) → Resistor → GND

Pin Mapping Example:

The resistor protects the LED from excessive current.

Circuit Setup Steps

1. Place the Arduino and breadboard on a flat surface
2. Insert 5 LEDs into the breadboard
3. Connect a 220Ω resistor from each LED’s negative leg to GND
4. Connect LED positive legs to Arduino pins D2–D6
5. Connect Arduino GND to breadboard GND rail

Arduino Code (5-LED Chaser)

int leds[] = {2, 3, 4, 5, 6};
int totalLeds = 5;

void setup() {
  for (int i = 0; i < totalLeds; i++) {
    pinMode(leds[i], OUTPUT);
  }
}

void loop() {
  // Forward direction
  for (int i = 0; i < totalLeds; i++) {
    digitalWrite(leds[i], HIGH);
    delay(200);
    digitalWrite(leds[i], LOW);
  }

  // Reverse direction
  for (int i = totalLeds - 1; i >= 0; i--) {
    digitalWrite(leds[i], HIGH);
    delay(200);
    digitalWrite(leds[i], LOW);
  }
}

How the Code Works

• int leds[] – Stores Arduino pin numbers connected to LEDs
• setup() – Sets all LED pins as OUTPUT
• loop() – Runs LEDs forward and backward in sequence
• delay(200) – Controls the chasing speed

Customization Ideas

• Change Speed
  delay(100); – Faster
  delay(500); – Slower
• One Direction Only – Remove the reverse loop
• Add RGB LEDs – Create color chasing effects
• Sound Reactive – Use a sound sensor for music-based lighting

Real-World Applications

• Decorative lighting
• Festival & event lighting
• Automotive indicators
• Learning base for IoT projects
• Signboards & displays

Learning Outcomes

• Arduino digital I/O
• LED polarity & resistors
• Loop-based logic
• Timing control using delay()

Source Code (GitHub)

👉 Full project source code is available on GitHub:
https://github.com/iamsss/5-LED-Chaser-Arduino

Conclusion

The 5-LED Chaser Arduino Project is a perfect starting point for anyone entering electronics or IoT. It builds confidence and prepares you for advanced projects like traffic lights, smart indicators, and IoT lighting systems.