#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27,16,2);

const int trig = 13;
const int echo = 12;
const int buzzer = 14;

float ss = 0.034;
float dist_cm;
long durn;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);

  lcd.init();

  pinMode(trig, OUTPUT);
  pinMode(echo, INPUT);

  pinMode(buzzer, OUTPUT);
}

void loop() {
  
  digitalWrite(trig, LOW);
  delayMicroseconds(2);
  digitalWrite(trig, HIGH);
  delayMicroseconds(10);
  digitalWrite(trig, LOW);

  durn = pulseIn(echo, HIGH);
  dist_cm = durn*ss/2;

  lcd.backlight();

  if(dist_cm <= 400 && dist_cm > 300) {
    lcd.setCursor(0,0);
    lcd.print("Jarak = Jauh");

    lcd.setCursor(1,1);
    lcd.print(dist_cm);

    digitalWrite(buzzer, HIGH);
    delay(1000);
    digitalWrite(buzzer, LOW);

  } else if (dist_cm <= 300 && dist_cm > 200) {
    lcd.setCursor(0,0);
    lcd.print("Jarak = Menengah");

    lcd.setCursor(1,1);
    lcd.print(dist_cm);

    digitalWrite(buzzer, HIGH);
    delay(500);
    digitalWrite(buzzer, LOW);

  } else {
    lcd.setCursor(0,0);
    lcd.print("Jarak = Dekat");

    lcd.setCursor(1,1);
    lcd.print(dist_cm);

    digitalWrite(buzzer, HIGH);
    delay(100);
    digitalWrite(buzzer, LOW);

  }



  Serial.print("Jarak = ");
  Serial.println(dist_cm);

  delay(100);
}