KY-050 Ultrasonic Distance Sensor Module

#define echoPin 7 // Echo input pin
#define triggerPin 8 // Trigger output pin

// Required variables are defined
int maximumRange = 300; 
int minimumRange = 2; 
long distance;
long duration;

void setup() {
  pinMode(triggerPin, OUTPUT);
  pinMode(echoPin, INPUT);
  Serial.begin(9600);
  Serial.println("KY-050 Distance measurement");
}

void loop() {
  // Distance measurement is started using the 10us trigger signal
  digitalWrite(triggerPin, HIGH);
  delayMicroseconds(10); 
  digitalWrite(triggerPin, LOW);

  // Now wait at the echo input until the signal has been activated
  // and then the time is measured to see how long it remains activated 
  duration = pulseIn(echoPin, HIGH);

  // Now the distance is calculated using the recorded time
  distance = duration / 58.2;

  // Check whether the measured value is within the permissible distance
  if (distance >= maximumRange || distance <= minimumRange) {
    // If not, an error message is displayed.
    Serial.println("Distance outside the measuring range");
    Serial.println("-----------------------------------");
  }  
  else {
    // The calculated distance is output in the serial output
    Serial.print("The distance is: ");
    Serial.print(distance);
    Serial.println(" cm");
    Serial.println("-----------------------------------");
  }
  // Pause between the individual measurements
  delay(500);
}