 unsigned int sensor_values[NUM_SENSORS];
 // this might need to be tuned for different lighting conditions, surfaces, etc.
 #define QTR_THRESHOLD  1500 // microseconds
-ZumoReflectanceSensorArray sensors(pins, 2, 2000, QTR_NO_EMITTER_PIN); 
+ZumoReflectanceSensorArray sensors(pins, 2, 2000, QTR_NO_EMITTER_PIN);
 
 // Motor Settings
 ZumoMotors motors;
 
- // Timing
+// Timing
 unsigned long loop_start_time = millis();
 unsigned long last_turn_time;
 unsigned long contact_made_time;


void turn(char direction, bool randomize)
{
  
  static unsigned int duration_increment = TURN_DURATION / 4;
  
  // motors.setSpeeds(0,0);
  // delay(STOP_DURATION);
      
  motors.setSpeeds(-FULL_SPEED, -FULL_SPEED);
  delay(REVERSE_DURATION);
  motors.setSpeeds(FULL_SPEED * direction, -FULL_SPEED * direction);
  delay(randomize ? TURN_DURATION + (random(8) - 2) * duration_increment : TURN_DURATION);
  motors.setSpeeds(0,0);
  last_turn_time = millis();
}


  // put your setup code here, to run once:
  //motors.flipLeftMotor(true);
  //motors.flipRightMotor(true);

  pinMode(LED, OUTPUT);
  digitalWrite(13, HIGH);
  //Serial.begin(9600);
  //pinMode(A4, INPUT);
  //pinMode(A5, INPUT);
  //digitalWrite(A4, LOW);
  //digitalWrite(A5, LOW);

  randomSeed((unsigned int) millis());

  // Play a little welcome song
