Arduino Project

Arduino LED Chaser with Push Buttons V2

Kit purchase

Looking for parts? Check out our all-in-one kits below — packed with components, beginner-friendly guides, and tons of fun.

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Name	Includes Arduino board	PURCHASE LINK
Elite Explorer Kit	Arduino Uno R4 WiFi	BUY
3 in 1 Ultimate Starter Kit	Arduino Uno R4 Minima	BUY
Ultimate Sensor Kit	Arduino Uno R4 Minima	BUY
Universal Maker Sensor Kit	×	BUY

Course Introduction

In this lesson, you will use Arduino together with two Ultrasonic Sensor Modules and a row of LEDs to create an automatic directional light-flow effect. When the left sensor detects an object, the LEDs light up in a forward flowing pattern.

When the right sensor is triggered, the LEDs flow in the opposite direction.

Each sensor controls one direction of the animation, allowing the LEDs to respond dynamically based on which side an obstacle is detected.

Note

If this is your first time working with an Arduino project, we recommend downloading and reviewing the basic materials first.

1.1 Install Arduino IDE(Important)
1.2 Introduction of Arduino IDE

Required Components

In this project, we need the following components:

SN	COMPONENT INTRODUCTION	QUANTITY	PURCHASE LINK
1	Arduino UNO R4 Minima	1	BUY
2	USB Type-C cable	1	×
3	Breadboard	1	BUY
4	Wires	Several	BUY
5	1kΩ resistor	Several	BUY
6	IR Obstacle Avoidance Sensor Module	2	BUY
7	LED	Several	BUY

Wiring

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Common Connections:

LED
Connect the LEDs cathode to the negative power bus on the breadboard, and the LEDs anode to 1kΩ resistor then to 5 to 10 on the Arduino.

Ultrasonic Sensor Module Right
Trig: Connect to 11 on the Arduino.
Echo: Connect to 12 on the Arduino.
GND: Connect to breadboard’s negative power bus.
VCC: Connect to breadboard’s red power bus.

Ultrasonic Sensor Module Left
Trig: Connect to 3 on the Arduino.
Echo: Connect to 4 on the Arduino.
GND: Connect to breadboard’s negative power bus.
VCC: Connect to breadboard’s red power bus.

Writing the Code

Note
You can copy this code into Arduino IDE.
Don’t forget to select the board(Arduino UNO R4 Minima) and the correct port before clicking the Upload button.

// Obstacle sensors
// These sensors output LOW when an object is detected
const int sensorLeft  = 3;     // Triggers forward flow
const int sensorRight = 12;    // Triggers backward flow

// LED pins in order from left to right
const int ledPins[] = {5, 6, 7, 8, 9, 10};
const int ledCount = 6;

// Time between LED steps
int delayTime = 80;

void setup() {

  // Set all LEDs as outputs
  for (int i = 0; i < ledCount; i++) {
    pinMode(ledPins[i], OUTPUT);
  }

  // Sensors are digital inputs
  pinMode(sensorLeft, INPUT);
  pinMode(sensorRight, INPUT);
}

void loop() {

  // Read sensors (LOW means obstacle found)
  bool leftDetected  = (digitalRead(sensorLeft) == LOW);
  bool rightDetected = (digitalRead(sensorRight) == LOW);

  // Forward flow: LEDs move from pin 5 → 10
  if (leftDetected) {
    for (int i = 0; i < ledCount; i++) {
      digitalWrite(ledPins[i], HIGH);   // Light current LED
      delay(delayTime);

      if (i > 0) {
        digitalWrite(ledPins[i - 1], LOW); // Turn off previous LED
      }
    }
    digitalWrite(ledPins[ledCount - 1], LOW); // Clear last LED
  }

  // Backward flow: LEDs move from pin 10 → 5
  if (rightDetected) {
    for (int i = ledCount - 1; i >= 0; i--) {
      digitalWrite(ledPins[i], HIGH);   // Light current LED
      delay(delayTime);

      if (i < ledCount - 1) {
        digitalWrite(ledPins[i + 1], LOW); // Turn off previous LED
      }
    }
    digitalWrite(ledPins[0], LOW); // Clear last LED
  }
}

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Arduino Project

Arduino LED Chaser with Push Buttons V2

Kit purchase

Course Introduction

Required Components

Wiring

Common Connections:

Writing the Code

Arduino Project

Arduino LED Chaser with Push Buttons V2

Kit purchase

Course Introduction

Required Components

Wiring

Common Connections:

Writing the Code

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