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

LiquidCrystal_I2C lcd(0x27,16,2); 

#define dhtpin 6
#define DHTTYPE DHT22
DHT dht(dhtpin, DHTTYPE);

int led1 = 8;
int led2 = 9; //LED
int led3 = 10;
int ldr1 = A0;

String d0, d1, d2, d3;
RTC_DS1307 RTC;

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

void setup() {
  // put your setup code here, to run once:
    pinMode(ldr1, INPUT);
    lcd.init(); 
    lcd.backlight();
    lcd.clear();
    Serial.begin(9600);
    dht.begin();
    pinMode(led1, OUTPUT);
    pinMode(led2, OUTPUT);
    pinMode(led3, OUTPUT);
    RTC.begin();
    

}

void loop() {
   float voltage = analogRead(ldr1) / 1024. * 5;
  float resistance = 2000 * voltage / (1 - voltage / 5);
  float lux = pow(RL10 * 1e3 * pow(10, GAMMA) / resistance, (1 / GAMMA));
  lcd.setCursor(7,1);
  lcd.print("lux =");
  lcd.print(lux);
  delay(500);
  if (lux > 500) { 
    digitalWrite(led1, HIGH); 
  }
  else {
    digitalWrite(led1, LOW);
  }
    float t = dht.readTemperature();
    lcd.setCursor(0,0); lcd.print("T: "); lcd.print(t);
    if (t > 25){
      digitalWrite(led2, HIGH);
    }
    else {
      digitalWrite(led2, LOW);
  }
    DateTime dt = RTC.now();
    String hour = String(dt.hour());
    if (hour.length() == 2) {   
      d0 = String(dt.hour()).substring(0,1);
      d1 = String(dt.hour()).substring(1,2);
    } else{
      d0 = "0";
      d1 = String(dt.hour()).substring(0,1);
    }

String minute = String(dt.minute());
  if(minute.length() == 2) {  
     d2 = String(dt.minute()).substring(0,1);  
     d3 = String(dt.minute()).substring(1,2); 
      }else{ 
  d2 = "0"; 
  d3 = String(dt.minute()).substring(0,1);
   } 
    lcd.setCursor(0,1);
     lcd.print(dt.hour()); lcd.print(":"); lcd.print(dt.minute());



  }