#define ledPin 13 // choose the pin for the LED 
#define switchPin 7 // choose the input pin (for a pushbutton)
const int trigPin = 9;
const int echoPin = 10;
// defines variables
long duration;
int distance;

int val = 0; // variable for reading the pin status

void setup()
{
  pinMode(ledPin, OUTPUT); // declare LED as output
  pinMode(switchPin, INPUT); // declare pushbutton as input
 
 pinMode(trigPin, OUTPUT); // Sets the trigPin as an Output
 pinMode(echoPin, INPUT); // Sets the echoPin as an Input
 Serial.begin(9600); // Starts the serial communication
}

void loop()
{
  val = digitalRead(switchPin); // read input value
  if (val == HIGH)
  { // check if the input is HIGH (button released)
    digitalWrite(ledPin, HIGH); // turn LED OFF
  } else {
    digitalWrite(ledPin, LOW); // turn LED ON } }
  }

   // Clears the trigPin
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  // Sets the trigPin on HIGH state for 10 micro seconds
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  // Reads the echoPin, returns the sound wave travel time in microseconds
  duration = pulseIn(echoPin, HIGH);
  // Calculating the distance
  distance = duration * 0.034 / 2;
  // Prints the distance on the Serial Monitor
  Serial.print("Distance: ");
  Serial.println(distance);
}