int time;
int distance;

void setup() {
pinMode(13, OUTPUT);
pinMode(12, INPUT);
Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite(13, HIGH);
delayMicroseconds(10);
digitalWrite(13, LOW);
delayMicroseconds(10);


time = pulseIn(12, HIGH);

distance = 0.0343*time/2;

Serial.print(distance);

}