#include "DHT.h"
#include <LiquidCrystal_I2C.h>
#include "RTClib.h"

RTC_DS1307 rtc;
#define I2C_ADDR    0x27
#define LCD_COLUMNS 20
#define LCD_LINES   4
#define DHTTYPE DHT22 
#define DHTPIN 2    
DHT dht(DHTPIN, DHTTYPE);
LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);

#define LDR_PIN 2
const float GAMMA = 0.7;
const float RL10 = 50;


void setup() {
  Serial.begin(9600);
  
  pinMode(LDR_PIN, INPUT);
   lcd.init();
  lcd.backlight();
  Serial.println(F("DHTxx test!"));
  dht.begin();
  if (! rtc.begin()) {
  Serial.println("Couldn't find RTC");
  while (1);
  }
  rtc.adjust(DateTime(F(__DATE__), F(__TIME__)));
}


void loop() {
  // Wait a few seconds between measurements.

  delay(2000);
  lcd.clear();

  DateTime now = rtc.now();

  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));


  float h = dht.readHumidity();
  float t = dht.readTemperature();

  int hour = now.hour();
  int minute = now.minute();
  int second = now.second();

  lcd.setCursor(0, 0);
  lcd.print("Humidity:  ");
  lcd.println(h);

  lcd.setCursor(0, 1);
  lcd.print("Temperature: ");
  lcd.println(t);

  lcd.setCursor(0, 2);
  lcd.print("Lux: ");
  lcd.println(lux);

  lcd.setCursor(0, 3);
  lcd.print("Time: ");
  lcd.print(hour);
  lcd.print(':');
  lcd.println(minute);
 lcd.print(':');
 lcd.print(second);

  


  Serial.print(F("Humidity: "));
  Serial.print(h);
  Serial.print(F("%  Temperature: "));
  Serial.print(t);
  Serial.print(F("°C "));
  Serial.print(now.year(), DEC);
Serial.print('/');
Serial.print(now.month(), DEC);
Serial.print('/');
Serial.print(now.day(), DEC);
Serial.print(" (");
Serial.print(now.dayOfTheWeek());
Serial.print(") ");
Serial.print(now.hour(), DEC);
Serial.print(':');
Serial.print(now.minute(), DEC);
Serial.print(':');
Serial.println(now.second(), DEC);
}