#include <Wire.h>
#include <LiquidCrystal_I2C.h>

const int trigger = 4;   
const int echo = 3;   
const int led = 5;

LiquidCrystal_I2C lcd(0x27, 16,2);

void setup() {
  // put your setup code here, to run once:
  lcd.begin(16,2);
  lcd.backlight();
  pinMode(led, OUTPUT);
  pinMode(trigger, OUTPUT);
  pinMode(echo, INPUT);
}

void loop() {
 
  digitalWrite(trigger, LOW);
  delayMicroseconds(5);
  digitalWrite(trigger, HIGH);
  delayMicroseconds(13);
  digitalWrite(trigger, LOW);
  long duration = pulseIn(echo, HIGH);
  long kedalaman = (duration * 0.0343) / 2;

if(kedalaman >30){
  digitalWrite(led, HIGH);
  lcd.setCursor(0,0);
  lcd.print("LED ON ");
}
else if(kedalaman <30 ){
  digitalWrite(led, LOW);
  lcd.setCursor(0,0);
  lcd.print("LED OFF");
}}