#include <LiquidCrystal_I2C.h>
#define LED 13

int inputPin = 2;
int pirState = LOW;
int val = 0;

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

LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup() {
  // put your setup code here, to run once:
  pinMode(LED, OUTPUT);
  pinMode(inputPin, INPUT);
  Serial.begin(9600);
  lcd.init();
  lcd.backlight();
    
  }

void loop() {
  // put your main code here, to run repeatedly:
  int analogValue = analogRead(A0);
  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);
    lcd.setCursor(0,1);
    lcd.print("Lux : ");
    lcd.print(lux);
  } 
  else {
    lcd.print("Gelap!");
    digitalWrite(LED, HIGH);
    lcd.setCursor(0,1);
    lcd.print("Lux : ");
    lcd.print(lux);

    val = digitalRead(inputPin);
    if (val == HIGH){
      digitalWrite(LED, HIGH);
      if (pirState == LOW){
        Serial.println("Gerakan Terdeteksi !");
        pirState = HIGH;
      }
    else {
      digitalWrite(LED, LOW);
      if (pirState == HIGH){
        Serial.println("Tidak ada Gerakan !");
        pirState = LOW;
      }
    }


  }
}
}