int distance;
int time;
void setup() {
  pinMode(13, OUTPUT);
  pinMode(12, INPUT);
  Serial.begin(115200);
// put your setup code here, to run once:

}

void loop() {
  digitalWrite(13, LOW);
  delay(1000);
  digitalWrite(13, HIGH);
  delay(1000);
  digitalWrite(13, LOW);
  
  time=pulseIn(12,HIGH);
  distance=0.0346/2*time;
  Serial.println(distance);
  delay(1000);
  // put your main code here, to run repeatedly:

}