/* Modified sketch taken from
 * Rui Santos, https://randomnerdtutorials.com
 */

// defines pins numbers
int trigPin = 9;    //Trigger
int echoPin = 10;    //Echo
long duration, cm;   //Time between the emission and reception of the signal
int distance;
// defines variables
void setup() {
  //Serial Port begin
  Serial.begin (9600); //Initialize the serial port at a baud rate of 9600 and start serial communication
  //Define inputs and outputs
  pinMode(trigPin, OUTPUT); //trigger pin as an output
  pinMode(echoPin, INPUT); //echo pin as an input
}
 
void loop() {
  // The sensor is triggered by a HIGH pulse of 10 or more microseconds.
  // Give a short LOW pulse beforehand to ensure a clean HIGH pulse:
  digitalWrite(trigPin, LOW);
  delayMicroseconds(5);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
 
  // Read the signal from the sensor: a HIGH pulse whose
  // duration is the time (in microseconds) from the sending
  // of the ping to the reception of its echo off of an object.
  pinMode(echoPin, INPUT);
  // Reads the echoPin, returns the sound wave travel time in microseconds
  duration = pulseIn(echoPin, HIGH);

// Calculating the distance
distance= duration*0.034/2;

if (distance >= 400 || distance <= 2){
Serial.print("Out of range");
Serial.println();
}

else {
// Prints the distance on the Serial Monitor
Serial.print("Distance, cm: ");
Serial.println(distance);
}

delay(1000);
}