//Motion at Night

#include <LiquidCrystal_I2C.h>

#define LED_PIN 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(LED_PIN, OUTPUT);
  pinMode(inputPin, INPUT);
  lcd.init();
  lcd.backlight();
  lcd.clear();
}

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));
  
  val = digitalRead(inputPin);

  lcd.setCursor(0, 0);
  lcd.print("Cahaya: ");

  if (val == HIGH && lux < 50) {
    lcd.print("Movement");
    digitalWrite(LED_PIN, HIGH);
  } 
  if (val == HIGH && lux > 50) {
    lcd.print(" ");
    digitalWrite(LED_PIN, LOW);
  } 
  if (val == LOW && lux > 50) {
    lcd.print("Terang");
    digitalWrite(LED_PIN, LOW);
  } 
  if (val == LOW && lux < 50) {
    lcd.print("Gelap");
    digitalWrite(LED_PIN, LOW);
  } 

  lcd.setCursor(0, 1);
  lcd.print("Lux: ");
  lcd.print(lux);
  lcd.print("          ");
  
  delay(100);
}