void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(13, OUTPUT);
  pinMode(14, INPUT);

}

void loop() {
digitalWrite(13, HIGH);
delay(1000);
digitalWrite(13, LOW);
float duration = pulseIn(14, HIGH);
int distance = duration * 0.034/2;
Serial.println(distance);
}