Arduino Line Follower Robot Circuit

This project is for Arduino Line Follower Robot Circuit.

Robot can follow black line on white floor.

It use Arduino, L298N motor driver and two IR sensors.

IR sensors see line and send signal to Arduino.

Arduino control motors and move robot on path.

Very simple and fun project.

Good for learning and school use.

Arduino Coding:

int leftIR = 2;
int rightIR = 3;
int in1 = 5;
int in2 = 6;
int in3 = 9;
int in4 = 10;

void setup() {
  pinMode(leftIR, INPUT);
  pinMode(rightIR, INPUT);
  pinMode(in1, OUTPUT);
  pinMode(in2, OUTPUT);
  pinMode(in3, OUTPUT);
  pinMode(in4, OUTPUT);
}

void loop() {
  int leftVal = digitalRead(leftIR);
  int rightVal = digitalRead(rightIR);

  if (leftVal == 1 && rightVal == 1) {
    forward();
  } 
  else if (leftVal == 0 && rightVal == 1) {
    leftTurn();
  } 
  else if (leftVal == 1 && rightVal == 0) {
    rightTurn();
  } 
  else {
    stopMotor();
  }
}

void forward() {
  digitalWrite(in1, HIGH);
  digitalWrite(in2, LOW);
  digitalWrite(in3, HIGH);
  digitalWrite(in4, LOW);
}

void leftTurn() {
  digitalWrite(in1, LOW);
  digitalWrite(in2, LOW);
  digitalWrite(in3, HIGH);
  digitalWrite(in4, LOW);
}

void rightTurn() {
  digitalWrite(in1, HIGH);
  digitalWrite(in2, LOW);
  digitalWrite(in3, LOW);
  digitalWrite(in4, LOW);
}

void stopMotor() {
  digitalWrite(in1, LOW);
  digitalWrite(in2, LOW);
  digitalWrite(in3, LOW);
  digitalWrite(in4, LOW);
}

Code Explanation:

• leftIR and rightIR are pins for IR sensor.
• motorLeft and motorRight pins control L298N driver.
• forward function make both motors go forward.
• leftTurn and rightTurn spin motors opposite to turn robot.
• IR sensor give 1 on white and 0 on black line.
• Arduino read sensor and decide where to go.

Circuit Working:

Parts List:

Part Name	Quantity
Arduino UNO R3	1
L298N Motor Driver	1
IR Sensor	2
DC Motors with Wheels	4
7V to 12V Battery	1
SPST Toggle switch	1
Robot Chassis	1

IR sensors keeps watching the surface.

If both see white then robot goes straight.

If left sensor see black then robot turns left.

If right sensor see black then robot turns right.

If both see black then robot stops or wait.

Arduino read sensor signal.

Then send command to L298N driver.

Driver control motor speed and direction.

Robot follow black line on white floor by itself.

How to Build:

To build a Arduino Line Follower Robot Circuit follow the below steps:

• Assemble all parts like in circuit diagram.
• Left IR sensor output go to Arduino pin 2.
• Right IR sensor output go to Arduino pin 3.
• Both IR sensor VCC go to Arduino 5V.
• Both sensor GND go to Arduino GND.
• L298N IN1 go to Arduino pin 5.
• L298N IN2 go to Arduino pin 6.
• L298N IN3 go to Arduino pin 9.
• L298N IN4 go to Arduino pin 10.
• Motor A wires go to OUT1 and OUT2.
• Motor B wires go to OUT3 and OUT4.
• L298N 12V pin go to battery positive.
• Battery negative go to GND.
• Connect switch to the positive of battery.

Conclusion:

This is simple Arduino Line Follower Robot Circuit.

Good for learning Arduino basics.

IR sensors see the line.

Arduino read signals and run motors with L298N driver.

Robot move and follow path by itself.

Easy to make and is good for beginners and school project.

References:

How do I make a line follower robot with three IR sensor using Arduino Uno?