#include <Wire.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16,2);
const int triggerPin = 2;
const int echoPin = 3;
const int LED1 = 4;

long durasi;
int jarak;

void setup() {
 lcd.init();
  lcd.clear();
  lcd.backlight();
  
     pinMode(triggerPin, OUTPUT); 
     pinMode(echoPin, INPUT);  
    pinMode(LED1, OUTPUT);     
     Serial.begin(9600);       
}

void loop() {
  digitalWrite(triggerPin, LOW);
  delayMicroseconds(2);
  digitalWrite(triggerPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(triggerPin, LOW);
  durasi = pulseIn(echoPin, HIGH);
  jarak = durasi*0.034/2;

lcd.setCursor(0,0);        
lcd.print("Jarak:");   
lcd.print(jarak);             
lcd.print("   cm");
 lcd.setCursor(0,1);  
 lcd.print("LED1: ");    
 delay(1000);
  if(jarak > 30){
    lcd.print("ON "); 
    Serial.println("Jarak lebih dari 30cm");
    digitalWrite(LED1, HIGH);
    }if(jarak < 30){
      lcd.print("OFF"); 
    Serial.println("Jarak kurang dari 30cm");
    digitalWrite(LED1, LOW);
  }
}