Sensor.ino

#define echoPin 7
#define trigPin 8
#define LEDPin 13

int maximumRange = 200;
int minimumRange = 0;
long duration, distance;

void setup() {
  Serial.begin(9600);
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);
  pinMode(LEDPin, OUTPUT);
}

void loop() {
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  //Serial.println(duration);
  
  //Speed of Sound
  distance = duration/59;
  
  if (distance >= maximumRange || distance <= minimumRange) {
    Serial.println("-1");
    digitalWrite(LEDPin, HIGH);
  }
  else {
    Serial.println(distance);
    digitalWrite(LEDPin, LOW);
  }
  
  delay(50);
}