Autonomous Line Following Robot

A self-navigating robot built by our intermediate students using sensors and microcontrollers.

Beginner Level School Project Arduino Sensors Robotics

Project Overview

The Line Following Robot is designed to automatically follow a black line on a white surface. It uses infrared (IR) sensors to detect the line and a microcontroller (Arduino) to control the motors. This project is a great way for students to learn about robotics, sensors, and programming in a fun and practical way.

Key Learning Outcomes

Sensor Integration

Arduino Programming

Motor Control & Driver Circuit

Problem Solving & Debugging

Project Features

Automatically follows a black line
Uses IR sensors for line detection
Controlled by Arduino microcontroller
Simple and cost-effective design
Suitable for school and college level projects

Project Information

Level

Beginner

Target Age

12+ Years

Technology

Arduino, IR Sensor, Motor Driver

Build Time

3-5 Hours

Difficulty

Detailed Explanation

The robot uses two IR sensors placed at the front to detect the black line on the surface. The sensors send signals to the Arduino microcontroller, which then controls the DC motors through a motor driver to keep the robot on track.

This project introduces key concepts such as sensor reading, motor control, and conditional programming. It can be further enhanced with speed control, PID algorithm, or additional sensors for more advanced versions.

Hardware Bill of Materials (BOM)

Component	Specification	Quantity	Status
Arduino Uno R3	ATmega328P Microcontroller Board	1 pcs	Included
Dual IR Sensor Module	Infrared Obstacle / Line Tracking	2 pcs	Included
L298N Motor Driver	Dual H-Bridge DC Stepper Driver	1 pcs	Included
TT Gear DC Motors + Wheels	3-6V Dual Shaft with Rubber Tires	2 pcs	Included
Acrylic Robot Chassis Kit	Pre-drilled mounting holes with Caster	1 set	Included
18650 Battery Holder	2-Slot 7.4V Output with Switch	1 pcs	Included

Pinout & Wiring Connections

IR Sensors to Arduino

Left IR VCC → Arduino 5V
Left IR GND → Arduino GND
Left IR OUT → Arduino Digital Pin 9
Right IR OUT → Arduino Digital Pin 10

L298N Driver to Arduino

IN1 / IN2 → Digital Pins 5 & 6 (PWM)
IN3 / IN4 → Digital Pins 10 & 11 (PWM)
12V Terminal → Battery (+) Positive
GND Terminal → Common GND

line_follower_robot.ino

// Line Following Robot Firmware
const int leftSensorPin = 9;
const int rightSensorPin = 10;
const int motorLeftFwd = 5;
const int motorRightFwd = 6;

void setup() {
  pinMode(leftSensorPin, INPUT);
  pinMode(rightSensorPin, INPUT);
  pinMode(motorLeftFwd, OUTPUT);
  pinMode(motorRightFwd, OUTPUT);
}

void loop() {
  int leftVal = digitalRead(leftSensorPin);
  int rightVal = digitalRead(rightSensorPin);

  if (leftVal == LOW && rightVal == LOW) {
    // Both on black line -> Move Forward
    analogWrite(motorLeftFwd, 180);
    analogWrite(motorRightFwd, 180);
  } else if (leftVal == HIGH && rightVal == LOW) {
    // Veer Left
    analogWrite(motorLeftFwd, 0);
    analogWrite(motorRightFwd, 180);
  } else if (leftVal == LOW && rightVal == HIGH) {
    // Veer Right
    analogWrite(motorLeftFwd, 180);
    analogWrite(motorRightFwd, 0);
  } else {
    // Stop
    analogWrite(motorLeftFwd, 0);
    analogWrite(motorRightFwd, 0);
  }
}