Example for FireFighter Fan to Search Straight.

SearchStraight.ino

int seq = 0;
int DCMOTOR = 4;
int PWM_SPEED = 100;
int SPEED_MOTOR = 100;
int state = 0;
int d2 = 400;
boolean fire = false;
boolean search = false;
int DELAY = 100;
void setup() {
  // put your setup code here, to run once:
  pinMode(DCMOTOR, OUTPUT);

  // FLAME SENSORS
  pinMode(5, INPUT); //FS_RIGHT
  pinMode(6, INPUT); //FS_CENTER
  pinMode(7, INPUT); //FS_LEFT

  //MOTOR PINS
  pinMode(8, OUTPUT); //dirmotor1
  pinMode(9, OUTPUT); //spdmotor1
  pinMode(10, OUTPUT);     //spdmotor2
  pinMode(11, OUTPUT);     //dirmotor2

}

void loop() {
  // put your main code here, to run repeatedly:
  int FLAME_RIGHT = digitalRead(5);
  int FLAME_CENTER = digitalRead(6);
  int FLAME_LEFT = digitalRead(7);

  if (seq == 3 ) {
    STOP();
  } else {
    FORWARD();
    if (FLAME_CENTER == 0) {
      STOP();
      state = 1;

      PUT_OFF_FIRE();
      seq = seq + 1;
    }
    else if (FLAME_RIGHT == 0) {
      STOP();
      state = 2;
      TURN_RIGHT();
      delay(d2);

      PUT_OFF_FIRE();
      seq = seq + 1;
    }
    else if (FLAME_LEFT == 0) {
      STOP();
      state = 3;
      TURN_LEFT();
      delay(d2);

      PUT_OFF_FIRE();
      seq = seq + 1;
    }
  }

}




void PUT_OFF_FIRE() {

  STOP();
  delay(1000);
  //  digitalWrite(RELAY_DC, HIGH);
  digitalWrite(DCMOTOR, HIGH);
  delay(5000);
  digitalWrite(DCMOTOR, LOW);
  delay(1000);
  switch (state) {
    case 1:
      delay(d2);
      state = 0;
      break;
    case 2:
      TURN_LEFT();
      delay(d2);
      state = 0;
      break;
    case 3:
      TURN_RIGHT();
      delay(d2);
      state = 0;
      break;
  }


}

void FORWARD() {
  digitalWrite(8, HIGH);
  analogWrite(9, SPEED_MOTOR);
  analogWrite(10, SPEED_MOTOR);
  digitalWrite(11, HIGH);
}
void TURN_RIGHT() {
  digitalWrite(8, HIGH);
  analogWrite(9, SPEED_MOTOR);
  analogWrite(10, SPEED_MOTOR);
  digitalWrite(11, LOW);
}
void TURN_LEFT() {
  digitalWrite(8, LOW);
  analogWrite(9, SPEED_MOTOR);
  analogWrite(10, SPEED_MOTOR);
  digitalWrite(11, HIGH);
}
void STOP() {
  //digitalWrite(8, HIGH);
  analogWrite(9, 0);
  analogWrite(10, 0);
  //digitalWrite(11, HIGH);
}