#include <LiquidCrystal_I2C.h>

int ledPin = 2;                
int inputPin = 3;               
int pirState = LOW; 
int val = 0; 

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

LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup() {
  pinMode(ledPin, OUTPUT);      
  pinMode(inputPin, INPUT);     
  Serial.begin(9600);
  lcd.init();
  lcd.backlight();
}

void loop() {
  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");
    lcd.setCursor(0, 1);
    lcd.print("Lux: ");
    lcd.print(lux);
    lcd.print("          ");
  } 
  
  else {
    lcd.print("Gelap  "); 
    lcd.setCursor(0, 1);
    lcd.print("Lux: ");
    lcd.print(lux);
    lcd.print("          ");
    val = digitalRead(inputPin); 
    if (val == HIGH) {            
    digitalWrite(ledPin, HIGH);  
      if (pirState == LOW) {
      Serial.println("Gerakan Terdeteksi!");
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Kondisi:");
      lcd.setCursor(0, 1);
      lcd.print("Gerakan Terdeteksi");
      digitalWrite(ledPin, HIGH);
      delay(1000);
      pirState = HIGH;
      }
    } 
    else {
      digitalWrite(ledPin, LOW); 
      if (pirState == HIGH) {
      Serial.println("Tidak Ada Gerakan!");
      lcd.clear();
      lcd.setCursor(0, 0);
      lcd.print("Kondisi:");
      lcd.setCursor(0, 1);
      lcd.print("Tdk Ada Gerakan");
      digitalWrite(ledPin, LOW);
      delay(100);
      pirState = LOW;
      }
    }
  }
  delay(100);
}