LineFollowingCar.ino

/*
ARDUINO LINE FOLLOWING CAR

This code controls a line-following car built using an Uno Arduino, a motor driver, and an infrared sensor.
The car is programmed to follow a black line on a white surface using the sensor input.
The code uses the AFMotor library, which must be installed prior to uploading the code.
Pins and variables are defined at the beginning of the code, followed by motor and sensor declarations.

Created by Smriti Shukla, Samyak Jain, Vishal Sharma, and Sudhansu Khuntia.
*/

//including the libraries
// including the libraries
#include <AFMotor.h>

// defining pins and variables
#define left A0
#define right A1

// defining motors
AF_DCMotor motor1(1, MOTOR12_1KHZ);
AF_DCMotor motor2(2, MOTOR12_1KHZ);
AF_DCMotor motor3(3, MOTOR34_1KHZ);
AF_DCMotor motor4(4, MOTOR34_1KHZ);

void setup() {
  // declaring pin types
  pinMode(left, INPUT);
  pinMode(right, INPUT);

  // begin serial communication
  Serial.begin(9600);
}

void loop() {
  // printing values of the sensors to the serial monitor
  Serial.print("Left sensor: ");
  Serial.println(digitalRead(left));
  Serial.print("Right sensor: ");
  Serial.println(digitalRead(right));

  // line detected by both sensors
  if (digitalRead(left) == 0 && digitalRead(right) == 0) {
    // move forward
    motor1.run(FORWARD);
    motor1.setSpeed(150);
    motor2.run(FORWARD);
    motor2.setSpeed(150);
    motor3.run(FORWARD);
    motor3.setSpeed(150);
    motor4.run(FORWARD);
    motor4.setSpeed(150);
  }
  // line detected by left sensor
  else if (digitalRead(left) == 0 && digitalRead(right) == 1) {
    // turn left
    motor1.run(FORWARD);
    motor1.setSpeed(200);
    motor2.run(FORWARD);
    motor2.setSpeed(200);
    motor3.run(BACKWARD);
    motor3.setSpeed(200);
    motor4.run(BACKWARD);
    motor4.setSpeed(200);
  }
  // line detected by right sensor
  else if (digitalRead(left) == 1 && digitalRead(right) == 0) {
    // turn right
    motor1.run(BACKWARD);
    motor1.setSpeed(200);
    motor2.run(BACKWARD);
    motor2.setSpeed(200);
    motor3.run(FORWARD);
    motor3.setSpeed(200);
    motor4.run(FORWARD);
    motor4.setSpeed(200);
  }
  // line not detected by either sensor
  else if (digitalRead(left) == 1 && digitalRead(right) == 1) {
    // stop
    motor1.run(RELEASE);
    motor1.setSpeed(0);
    motor2.run(RELEASE);
    motor2.setSpeed(0);
    motor3.run(RELEASE);
    motor3.setSpeed(0);
    motor4.run(RELEASE);
    motor4.setSpeed(0);
  }
}