#include <LiquidCrystal_I2C.h>

#define led 2
int inputPin = 3;               
int pirState = LOW;             
int val = 0;  

const float GAMMA = 0.7;
const float RL10 = 50;

LiquidCrystal_I2C lcd(0x27, 20, 4);

void setup() {
  pinMode(led, OUTPUT);
  pinMode(inputPin, INPUT);     
  Serial.begin(9600);

  lcd.init();
  lcd.backlight();
}

void loop() {
  int analogValue = analogRead(A0);
  //val = digitalRead(inputPin);  
  float voltage = analogValue / 1024. * 5;
  float resistance = 2000 * voltage / (1 - voltage / 5);
  float lux = pow(RL10 * 1e3 * pow(10, GAMMA) / resistance, (1 / GAMMA));

  lcd.setCursor(0, 0);
  lcd.print("Cahaya: ");
  
  if (lux > 50 ) {
    lcd.print("Terang");
    digitalWrite(led, LOW);
    Serial.println("Gerakan Tidak Terdeteksi!");
    pirState = LOW;
  
   
  ///
  } else {
    lcd.print("Gelap  ");
    digitalWrite(led, HIGH);
    Serial.println("Gerakan Terdeteksi!");
    pirState = HIGH;
  }
   


  
  lcd.setCursor(0, 1);
  lcd.print("Lux: ");
  lcd.print(lux);
  lcd.print("          ");

  delay(100);
}