Arduino Based Line Follower Vehicle

A line follower robot which can follow a dark line on a bright surface.

https://www.youtube.com/watch?v=MXt_QuZyAjU

//My line follower car

int SensorLED = 3; //Define the LED of the Line Sensor
int button = 2;

int LeftMotorPlus = 8;
int LeftMotorMinus = 9;
int LeftMotorEnable = 10;

int RightMotorPlus = 12;
int RightMotorMinus = 13;
int RightMotorEnable = 11;

int sensor1 = 0;
int sensor2 = 0;
int sensor3 = 0;
int sensor4 = 0;
int sensor5 = 0;
int sensor6 = 0;
int sensor7 = 0;

void setup()
{
  Serial.begin(9600);

  pinMode(LeftMotorPlus, OUTPUT);
  pinMode(LeftMotorMinus, OUTPUT);
  pinMode(LeftMotorEnable, OUTPUT);

  pinMode(RightMotorEnable, OUTPUT);
  pinMode(RightMotorMinus , OUTPUT);
  pinMode(RightMotorPlus , OUTPUT);

  pinMode(SensorLED, OUTPUT);
}

void move_forward() {
  digitalWrite(LeftMotorEnable, HIGH);
  digitalWrite(RightMotorEnable, HIGH);

  digitalWrite(LeftMotorPlus, HIGH);
  digitalWrite(LeftMotorMinus, LOW);

  digitalWrite(RightMotorPlus, LOW);
  digitalWrite(RightMotorMinus, HIGH);
}
void move_backward() {
  digitalWrite(LeftMotorEnable, HIGH);
  digitalWrite(RightMotorEnable, HIGH);

  digitalWrite(LeftMotorPlus, LOW);
  digitalWrite(LeftMotorMinus, HIGH);

  digitalWrite(RightMotorPlus, HIGH);
  digitalWrite(RightMotorMinus, LOW);
}
void turn_left()
{
  analogWrite(LeftMotorEnable, 210);
  analogWrite(RightMotorEnable, 210);

  digitalWrite(LeftMotorPlus, HIGH);
  digitalWrite(LeftMotorMinus, LOW);

  digitalWrite(RightMotorPlus, HIGH);
  digitalWrite(RightMotorMinus, LOW);
}
void turn_right() {
  analogWrite(LeftMotorEnable, 210);
  analogWrite(RightMotorEnable, 210);

  digitalWrite(LeftMotorPlus, LOW);
  digitalWrite(LeftMotorMinus, HIGH);

  digitalWrite(RightMotorPlus, LOW);
  digitalWrite(RightMotorMinus, HIGH);
}
void stop_moving() {
  digitalWrite(LeftMotorEnable, LOW);
  digitalWrite(RightMotorEnable, LOW);

  digitalWrite(LeftMotorPlus, LOW);
  digitalWrite(LeftMotorMinus, LOW);

  digitalWrite(RightMotorPlus, LOW);
  digitalWrite(RightMotorMinus, LOW);
}

int  find_line_position() {

  digitalWrite(SensorLED, HIGH);//Turn on Sensor LED
  delay(1);

  //Read the sensors and display Serially
  int sensorValue1 = analogRead(A1);
  delay(1);
  sensorValue1 = analogRead(A1);
  if (sensorValue1 < 600 && sensorValue1 > 320) {
    sensor1 = 1;
  }
  else {
    sensor1 = 0;
  }

  Serial.println(sensorValue1);
  delay(1);
  int sensorValue2 = analogRead(A2);
  delay(1);
  sensorValue2 = analogRead(A2);
  if (sensorValue2 < 600 && sensorValue2 > 320) {
    sensor2 = 1;
  }
  else {
    sensor2 = 0;
  }
  Serial.println(sensorValue2);
  delay(1);
  int sensorValue3 = analogRead(A3);
  delay(1);
  sensorValue3 = analogRead(A3);
  if (sensorValue3 < 600 && sensorValue3 > 320) {
    sensor3 = 1;
  }
  else {
    sensor3 = 0;
  }
  Serial.println(sensorValue3);
  delay(1);
  int sensorValue4 = analogRead(A4);
  delay(1);
  sensorValue4 = analogRead(A4);
  if (sensorValue4 < 600 && sensorValue4 > 320) {
    sensor4 = 1;
  }
  else {
    sensor4 = 0;
  }
  Serial.println(sensorValue4);
  delay(1);
  int sensorValue5 = analogRead(A5);
  delay(1);
  sensorValue5 = analogRead(A5);
  if (sensorValue5 < 600 && sensorValue5 > 320) {
    sensor5 = 1;
  }
  else {
    sensor5 = 0;
  }
  Serial.println(sensorValue5);
  delay(1);
  int sensorValue6 = analogRead(A6);
  delay(1);
  sensorValue6 = analogRead(A6);
  if (sensorValue6 < 600 && sensorValue6 > 320) {
    sensor6 = 1;
  }
  else {
    sensor6 = 0;
  }
  Serial.println(sensorValue6);
  delay(1);
  int sensorValue7 = analogRead(A7);
  delay(1);
  sensorValue7 = analogRead(A7);
  if (sensorValue7 < 600 && sensorValue7 > 320) {
    sensor7 = 1;
  }
  else {
    sensor7 = 0;
  }
  Serial.println(sensorValue7);
  Serial.println(" ");
  //delay(3200);

  //Calculate the Line Position

  Serial.print(sensor1);
  Serial.print(sensor2);
  Serial.print(sensor3);
  Serial.print(sensor4);
  Serial.print(sensor5);
  Serial.print(sensor6);
  Serial.print(sensor7);
  Serial.println("");

  // Calculate the Decimal corresponding to the line position

  int dec = 1 * sensor7 + 2 * sensor6 + 4 * sensor5 + 8 * sensor4 + 16 * sensor3 + 32 * sensor2 + 64 * sensor1;
  Serial.print ("Detected line position is");
  Serial.println(dec);
  return dec;

}
int count = 0;
void loop()
{
  int line_position =  find_line_position();
  if (line_position > 0 && line_position < 7) //i.e. the line is on the right
  {
    turn_right();
    Serial.println("Line found on the right");
  }
  if (line_position > 7 &&  line_position < 31)//i.e line is on the center
  {
    move_forward();
    Serial.println("Line is in The Middle");
  }
  if (line_position > 31 &&  line_position < 127) //i.e. line is on the left
  {
    turn_left();
    Serial.println("Line is on the Left Side");
  }
  if (line_position == 127 || line_position == 0) {

    count = count + 1;
    Serial.print(" Current No line Timeout is");
    Serial.println(count);
    if (count > 250)
    {
      Serial.println("Stopping");
      stop_moving();
    }
  }
}