#include "Adafruit_TinyUSB.h"

const int out=12;
const int in=13;
const int led=10;


void setup(){
Serial.begin(115200);
pinMode(in, INPUT);
pinMode(out, OUTPUT);
pinMode(led, OUTPUT);
}

void loop()
{
long dur;
long dis;
long tocm;
digitalWrite(out,LOW);
delayMicroseconds(2);
digitalWrite(out,HIGH);
delayMicroseconds(10);
digitalWrite(out,LOW);
dur=pulseIn(in,HIGH);
tocm=microsecondsToCentimeters(dur);
Serial.println(String(tocm));
delay(100);

if (tocm < 15){

 digitalWrite(led, HIGH);
}

else{
  digitalWrite(led, LOW);
}



}

long microsecondsToCentimeters(long microseconds)
{
return microseconds / 29 / 2;
}