#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup()
{
  pinMode(2, INPUT);
  pinMode(3, OUTPUT); 
  pinMode(13, OUTPUT); 
  
  lcd.init();
  lcd.backlight();

}

void loop() {
  digitalWrite(3, HIGH);
  delayMicroseconds(10);
  digitalWrite(3, LOW);
  int d = pulseIn(2,HIGH);
  lcd.setCursor(0,0);
  lcd.print(d);
  int cm = d/58;
  lcd.setCursor(0,1);
  lcd.print(cm);
  delay(500);
  lcd.clear();
  if (cm <= 100 || cm>=300) {
    digitalWrite(13, HIGH);
  }else{
    digitalWrite(13, LOW);
}
}