line_follower.cpp

int leftInput=A3;
int rightInput=A4;
int leftMotor=13;
int rightMotor=12;
int leftValue = 0;
int rightValue = 0;

void setup()
{
    pinMode (leftMotor, OUTPUT);
    pinMode (rightMotor, OUTPUT);
}

void loop()
{
    leftValue = analogRead (leftInput);
    rightValue= analogRead (rightInput);

    if(leftValue < 900 && rightValue < 900)
    {
        digitalWrite (leftMotor, HIGH);
        digitalWrite (rightMotor, HIGH);
    }
    else
    {
        if(leftValue > 900 && rightValue < 900)
        {
            digitalWrite (leftMotor, LOW);
            digitalWrite (rightMotor, HIGH);
        }
        else {
            if (leftValue < 900 && rightValue > 900)
            {
                digitalWrite (rightMotor, LOW);
                digitalWrite (leftMotor, HIGH);
            }
            else
            {
                if (leftValue > 900 && rightValue > 900)
                {
                    digitalWrite (rightMotor, LOW);
                    digitalWrite (leftMotor, LOW);
                }
            }
        }
    }
}