How to Make a Line Follower Robot Car with Arduino UNO, L298N Motor Driver and IR Sensor

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INTRODUCTION

A line follower robot is a simple and popular beginner project in robotics. This robot follows a black line using IR sensors and controls motors using Arduino.

In this project, we use Arduino UNO, L298N motor driver, and IR sensors to build an automatic robot. This is perfect for students and beginners.

WATCH YOUTUBE VIDEO

Watch full working of Line Follower Robot:

COMPONENTS REQUIRED

Item Image	Item Name	Quantity	Buy
	Arduino UNO	1	{getButton} $text={Buy Now} $icon={cart} $color={#007bff}
	L298N Motor Driver	1	{getButton} $text={Buy Now} $icon={cart} $color={#007bff}
	IR Sensor Module	2	{getButton} $text={Buy Now} $icon={cart} $color={#007bff}
	DC BO Motors	4	{getButton} $text={Buy Now} $icon={cart} $color={#007bff}
	Robot Chassis	1	{getButton} $text={Buy Now} $icon={cart} $color={#007bff}
	Wheels	4	{getButton} $text={Buy Now} $icon={cart} $color={#007bff}
	18650 cells	2	{getButton} $text={Buy Now} $icon={cart} $color={#007bff}
	18650 cells holder	1	{getButton} $text={Buy Now} $icon={cart} $color={#007bff}
	Jumper Wires	As Required	{getButton} $text={Buy Now} $icon={cart} $color={#007bff}

TOOLS REQUIRED

Image	Tool Name	Quantity	Buy
	Screwdriver	1	{getButton} $text={Buy Tool} $icon={cart} $color={#007bff}
	Wire Cutter	1	{getButton} $text={Buy Tool} $icon={cart} $color={#007bff}
	Hot Glue Gun	1	{getButton} $text={Buy Tool} $icon={cart} $color={#007bff}
	Double Side Tape	Optional	{getButton} $text={Buy Tool} $icon={cart} $color={#007bff}

APPS AND ONLINE SERVICES

Image	App Name	Access
	Arduino IDE	{getButton} $text={download} $icon={download} $color={#007bff}
	Arduino Web Editor	{getButton} $text={Open} $icon={link} $color={#007bff}
	Tinkercad Circuits	{getButton} $text={Open} $icon={link} $color={#007bff}
	Google Chrome / Browser	{getButton} $text={download} $icon={download} $color={#007bff}

CIRCUIT DIAGRAM

Refer below image for wiring:

WIRING CONNECTIONS

Arduino ↔ IR Sensors

IR Sensor Pin	Arduino Connection
Left Sensor OUT	Pin 2
Right Sensor OUT	Pin 3
VCC	5V
GND	GND

Arduino ↔ L298N Motor Driver

L298N Pin	Arduino Connection
ENA	Pin 11 (PWM)
IN1	Pin 10
IN2	Pin 9
IN3	Pin 8
IN4	Pin 7
ENB	Pin 6 (PWM)
GND	GND

Motor Connections ↔ L298N

Motor	L298N Output
Left Motor (Motor A)	OUT1 & OUT2
Right Motor (Motor B)	OUT3 & OUT4

Power Connections

Component	Connection
Battery (+)	L298N 12V / VCC
Battery (-)	L298N GND
Arduino GND	L298N GND (Common Ground)
5V Output (L298N)	Arduino 5V (Optional)

ARDUINO CODE

// Motor A const int ENA = 11; // PWM pin for Motor A const int IN1 = 10; // IN1 pin for Motor A const int IN2 = 9; // IN2 pin for Motor A #define s 100 //base speed #define t 130//turning speed // Motor B const int ENB = 6; // PWM pin for Motor B const int IN3 = 8; // IN3 pin for Motor B const int IN4 = 7; // IN4 pin for Motor B // IR Sensors const int IRSensorLeft = 2; // Left IR sensor const int IRSensorRight = 3; // Right IR sensor void setup() { // Set motor pins as outputs pinMode(ENA, OUTPUT); pinMode(IN1, OUTPUT); pinMode(IN2, OUTPUT); pinMode(ENB, OUTPUT); pinMode(IN3, OUTPUT); pinMode(IN4, OUTPUT); // Set sensor pins as inputs pinMode(IRSensorLeft, INPUT); pinMode(IRSensorRight, INPUT); // Initialize serial communication for debugging Serial.begin(9600); } void loop() { bool leftSensor = digitalRead(IRSensorLeft); bool rightSensor = digitalRead(IRSensorRight); // Print sensor values Serial.print("Left Sensor: "); Serial.print(leftSensor); Serial.print(" | Right Sensor: "); Serial.println(rightSensor); // Forward movement if (leftSensor == LOW && rightSensor == LOW) { moveForward(); } // Turn right else if (leftSensor == LOW && rightSensor == HIGH) { turnRight(); } // Turn left else if (leftSensor == HIGH && rightSensor == LOW) { turnLeft(); } // Stop else { stopMotors(); } delay(100); // Add a short delay to make the print readable } void moveForward() { digitalWrite(IN1, HIGH); digitalWrite(IN2, LOW); analogWrite(ENA, s); // Adjust speed here digitalWrite(IN3, HIGH); digitalWrite(IN4, LOW); analogWrite(ENB, s); // Adjust speed here } void turnRight() { digitalWrite(IN1, LOW); digitalWrite(IN2, HIGH); analogWrite(ENA, t); // Adjust speed here digitalWrite(IN3, HIGH); digitalWrite(IN4, LOW); analogWrite(ENB, t); // Adjust speed here } void turnLeft() { digitalWrite(IN1, HIGH); digitalWrite(IN2, LOW); analogWrite(ENA, t); // Adjust speed here digitalWrite(IN3, LOW); digitalWrite(IN4, HIGH); analogWrite(ENB, t); // Adjust speed here } void stopMotors() { digitalWrite(IN1, LOW); digitalWrite(IN2, LOW); analogWrite(ENA, 0); // Stop motor digitalWrite(IN3, LOW); digitalWrite(IN4, LOW); analogWrite(ENB, 0); // Stop motor }

WORKING PRINCIPLE

IR sensors detect black and white surfaces. Black line gives LOW signal and white surface gives HIGH signal. Based on this, the robot moves forward, left, or right.

TIPS

• Adjust IR sensor using potentiometer
• Use black tape for best results
• Keep battery fully charged

Conclusion

This project helps beginners understand sensors, motors, and automation. It is the perfect starting point in robotics.

More projects coming soon 🚀