#include <LiquidCrystal_I2C.h>

//sensor PIR
#define pinPIR 3

//sensor LDR
#define pinLDR A0

//konstanta utk hitung lux
const float GAMMA = 0.7;
const float RL10 = 50;

//LED
#define pinLED 2

LiquidCrystal_I2C lcd(0x27, 20, 2);

void setup() {
  //mode tiap PIN
  pinMode(pinPIR, INPUT);
  pinMode(pinLED, OUTPUT);
  pinMode(pinLDR, INPUT);
  
  //inisialisasi LCD
  lcd.init();
  lcd.backlight();

  digitalWrite(pinLED, LOW);
}

void loop() {
  // put your main code here, to run repeatedly:

  //deteksi apakah udah malam ?
  int valueLDR= analogRead(A0);
  float voltage = valueLDR / 1024. * 5;
  float resistance = 2000 * voltage / (1 - voltage / 5);
  float lux = pow(RL10 * 1e3 * pow(10, GAMMA) / resistance, (1 / GAMMA));
  
  lcd.setCursor(1, 0); // posisikan text di (kolom=1,baris=0)
  //jika lux < 50 artinya gelap = malamg
  if (lux < 50) {
    //jika status MALAM
    lcd.print("Status : Malam  ");

    //deteksi apakah ada gerakan ?
    if (digitalRead(pinPIR) == HIGH) {
      //jika gerakan dideteksi
      lcd.setCursor(1, 1); // posisikan text di (kolom=1,baris=1)
      lcd.print("ada PENYUSUP!");
      //LED warning berkedip
      digitalWrite(pinLED, HIGH); delay(500);
      digitalWrite(pinLED, LOW); delay(500);
      digitalWrite(pinLED, HIGH); delay(500);
      digitalWrite(pinLED, LOW); delay(500);
    } else 
    {
      //jika tidak ada gerakan dideteksi
      lcd.setCursor(1, 1); // posisikan text di (kolom=1,baris=1)
      lcd.print("    Aman     ");
      digitalWrite(pinLED, LOW);  // led warning off    
    }

  } else
  {
    //jika status SIANG
    lcd.print("Status : Siang  ");
    digitalWrite(pinLED, LOW); // led warning off
  }


}