void setup() {
pinMode(13, OUTPUT);
pinMode(12, INPUT);
Serial.begin(115200);
}

void loop() {
int time;
int distance;
digitalWrite(13, LOW);
delay(1000);
digitalWrite(13, HIGH);
delay(1000);
digitalWrite(13, LOW);
time=pulseIn(12,HIGH);
distance =time*0.0346/2;
Serial.println(distance);

}