#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27, 16, 2);


#define trig 11
#define echo 10
#define buzzer 2
#define led 8

void setup() {

lcd.begin(16, 2);
pinMode(trig, OUTPUT);
pinMode(echo, INPUT);

}

 float readDistanceCM() {
  
  digitalWrite(trig, HIGH);
  delayMicroseconds(10);
  digitalWrite(trig, LOW);
  int duration = pulseIn(echo, HIGH);
  return duration * 0.017102;

  }

void loop() {
  
 float distance = readDistanceCM();
  Serial.print("Jarak = ");
  Serial.print(readDistanceCM());
  Serial.println(" cm");

  delay(500);

lcd.setCursor(0,0);
lcd.print("jarak");
lcd.setCursor(0,1);
lcd.print(distance);

 if (distance <50){
    
    digitalWrite(led, HIGH);
    tone(buzzer, 500);
    delay(210);
    noTone(buzzer);
    digitalWrite(led, LOW);
    delay(210);
  }

}