int trig=13;
int echo=12;
float d;
void setup()
{
  Serial.begin(115200);
pinMode(trig, OUTPUT);
pinMode(echo, INPUT);

}
int ultrasonic()
{
  digitalWrite(trig, LOW);
  delay(10);
  digitalWrite(trig, HIGH);
  delay(100);
  digitalWrite(trig, LOW);
  d=pulseIn(echo,HIGH);
  return(d*0.034/2);
  delay(1000);
}
void loop()
{
  
  Serial.println(d);
}