#include <RTClib.h> //Library for enabling real-time
#include <TimeLib.h>
#include <Wire.h> //Library for communication with real-time module (DS1307)
#include <LiquidCrystal.h> //LCD Display
LiquidCrystal lcd(2, 3, 4, 5, 6, 7);
RTC_DS1307 rtc; //Real-time value from DS1307
#define buz 11 //PWM Digital Port for buzzer alarm functionality
int Hor; //Current hour value for buzzer alarm
int Min; //Current minute value for buzzer alarm
int Sec;  //Current second value for buzzer alarm
const float BETA = 3950; //BETA Coefficient for the thermisor (temperature sensor)

void setup() {
  Wire.begin(); //Wire library for connecting to real-time module
  rtc.begin(); //Value for real-time
  Serial.begin(9600);
  pinMode(buz, OUTPUT); //Buzzer output
  lcd.begin(20,4); //20 character by 4 lines on LCD
  lcd.setCursor(0,0);
  lcd.print("IoT Alarm Clock"); //Introductary text to turning on alarm clock
  lcd.setCursor(0,1);
  lcd.print("Loading..."); //Loading text for line below
  delay(2000); //Takes 2000ms to load
  lcd.clear(); //Clears screen after 2000ms to load the alarm clock screen
  }

void loop() {
  int analogValue = analogRead(A3); //Analog input for temperature sensor
  float celsius = 1 / (log(1 / (1023. / analogValue - 1)) / BETA + 1.0 / 298.15) - 273.15; //Calculate celsius from the current BETA coefficent
  String temp = (String) celsius; //Put celcsius in temp string
  DateTime current = rtc.now(); //Put current time in "current" value
  Hor = current.hour(); //Current scheduled hour for buzzer alarm
  Min = current.minute(); //Current scheduled minute for buzzer alarm
  Sec = current.second(); //Current scheduled second for buzzer alarm
  lcd.setCursor(0,0); //Prints current time (Hour : Minute: Second) on first line
  lcd.print("Time: "); 
  lcd.print(current.hour(), DEC);
  lcd.print(":");
  lcd.print(current.minute(), DEC);
  lcd.print(":");
  lcd.print(current.second(), DEC);
  lcd.setCursor(0,1); //Prints current date on the second line (Day : Month: Year)
  lcd.print("Date: ");
  lcd.print(current.day(), DEC);
  lcd.print("-");
  lcd.print(current.month(), DEC);
  lcd.print("-");
  lcd.print(current.year(), DEC);
  lcd.setCursor(0,2);
  lcd.print("Temp: "); //Print current temperature from temp string value
  lcd.print(temp);
  lcd.print(" Celcius");

 if( Hor == 16 && (Min == 11 || Min == 12)) { //Manual hour and minute set for alarm buzzer
   BuzzerAlarm(); //Function rings the alarm once
   BuzzerAlarm();
   lcd.clear();
   lcd.print("Alarm Time");
   lcd.setCursor(0,1);
   lcd.print("Alarm in motion!");
   BuzzerAlarm();
   BuzzerAlarm();
 } 
 delay(1000);
}

void BuzzerAlarm() {
  digitalWrite(buz,HIGH); //Rings alarm
  delay(500);
  digitalWrite(buz, LOW); //Dims alarm after 500ms
  delay(500);
}