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

void loop()
{
int time;
int distance;


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