/*
This is a church bell controller.
The relay is for the hour bell.
The second relay is for ringing bell (please implement the ringing circuit seperatly)
You can implement a timer for second relay. I didnt made the timer code , Make your own
*/

#include "Wire.h"
#include <LiquidCrystal_I2C.h>

#define I2C_ADDR    0x27
#define LCD_COLUMNS 20
#define LCD_LINES   4

LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);

//BEGIN RTC CODE

//rtc variables
int second, minute, hour;
int dayOfWeek, dayOfMonth, month, year;
//end rtc variables

#define DS3231_I2C_ADDRESS 0x68

byte decToBcd(byte val) {
  return ( (val / 10 * 16) + (val % 10) );
}

// Convert binary coded decimal to decimal numbers
byte bcdToDec(byte val) {
  return ( (val / 16 * 10) + (val % 16) );
}

// Set the time
void rtc_setTime(byte second, byte minute, byte hour, byte wday, byte mday, byte mon, byte year) {
  // sets time and date data to DS3231
  Wire.beginTransmission(DS3231_I2C_ADDRESS);
  Wire.write(0); // set next input to start at the seconds register
  Wire.write(decToBcd(second)); // set seconds
  Wire.write(decToBcd(minute)); // set minutes
  Wire.write(decToBcd(hour)); // set hours

  Wire.write(decToBcd(wday)); // set day of week (1=Monday, 7=Sunday)
  Wire.write(decToBcd(mday)); // set date (1 to 31)
  Wire.write(decToBcd(mon)); // set month
  Wire.write(decToBcd(year)); // set year (0 to 99)
  
  Wire.endTransmission();
}

void rtc_readTime() {
  Wire.beginTransmission(DS3231_I2C_ADDRESS);
  Wire.write(0); // set DS3231 register pointer to 00h
  Wire.endTransmission();

  // request seven bytes of data from DS3231 starting from register 00h
  Wire.requestFrom(DS3231_I2C_ADDRESS, 7);
  second = bcdToDec(Wire.read() & 0x7f);
  minute = bcdToDec(Wire.read());
  hour = bcdToDec(Wire.read() & 0x3f);
  dayOfWeek = bcdToDec(Wire.read());
  dayOfMonth = bcdToDec(Wire.read());
  month = bcdToDec(Wire.read());
  year = bcdToDec(Wire.read());

  //leap year correction
  #define LEAP_YEAR(Y)     ( !(((Y))%4) && ( (((Y))%100) || !(((Y))%400) ) )

  if(LEAP_YEAR(year) == 0 && dayOfMonth == 29 && month == 2){
    rtc_setTime(second, minute, hour, dayOfWeek, 1, 3, year);
  }
}

void rtc_init(){
  Wire.begin(); 
}
//END RTC CODE

//timing variables
uint32_t previous, previous1;

//your bell pin
int relay_pin = 13;

//your ringing bell ( this is using a relay, so you have to make a circuit to make the bell ringing)
int bell_pin = 8;

//for menu setTime
byte s = 0,m,h,w = 1,d = 1,n = 1,y;

//for menu
int buttonP;

//for debounce delay
long debounceDel = 100;

void setup() {
  // Init lcd
  lcd.init();
  //lcd.begin();
  lcd.backlight();

  // Init rtc
  rtc_init();
  //for debug: 
  //rtc_setTime(55, 59, 23, 1,1,1,1);

  //init hour bell
  pinMode(relay_pin, OUTPUT);

  //init ringing bell
  pinMode(bell_pin, OUTPUT);

  //buttons
  pinMode(12, INPUT_PULLUP); //for menu display (black)
  pinMode(11, INPUT_PULLUP); //for setting time (green)
  pinMode(10, INPUT_PULLUP); //for ++ (blue)
  pinMode(9, INPUT_PULLUP); //for -- (red)

  //switch (for ringing bell)
  pinMode(7, INPUT_PULLUP);

}

void strike_bell(long interval1, long interval2){

  int varhour = 12;

  if(hour >= 13){
    varhour = hour - 12;
  }

  else if(hour == 0){
    varhour = 12;
  } 

  else {
    varhour = hour;
  }

  for(int i = 1; i <= varhour; i++){
    digitalWrite(relay_pin,1);
    delay(interval1);
    digitalWrite(relay_pin,0);
    delay(interval2);
  }
}

void loop() {
  rtc_readTime();
  
  if(buttonP == 0){
    displayDT();
  }
  else if(buttonP == 1){
    displaySY();
  }
  else if(buttonP == 2){
    displaySN();
  }
  else if(buttonP == 3){
    displaySD();
  }
  else if(buttonP == 4){
    displaySW();
  }
  else if(buttonP == 5){
    displaySH();
  }
  else if(buttonP == 6){
    displaySM();
  }
  else if(buttonP == 7){
    displayST();
  }


  if(!digitalRead(12)){
    delay(debounceDel);
    ++buttonP;
    if(buttonP >= 8){
      buttonP = 0;
    }
  }

  if(!digitalRead(7)){
    digitalWrite(bell_pin,1);
  } else {
    digitalWrite(bell_pin, 0);
  }
}

//lcd display

void displayDT(){
  //print datetime
  if(micros() - previous >= 500000){
    lcd.clear();
    char buffer[20];
    sprintf(buffer, "%02d:%02d:%02d", hour, minute, second);
    lcd.setCursor(0,0);
    lcd.print(buffer);
    sprintf(buffer, "%02d/%02d/%02d", (year%100), month, dayOfMonth);
    lcd.setCursor(12,0);
    lcd.print(buffer);
    previous = micros();
  }

  if(minute == 0 && second == 0){
    strike_bell(200, 700);
  }
}

void displaySY(){
  delay(debounceDel);
  lcd.clear();
  lcd.print("Set Year since 2000");
  lcd.setCursor(0,3);
  lcd.print(y);
  
  if(!digitalRead(10)){
    ++y;
  }

  if(!digitalRead(9)){
    --y;
  }
}

void displaySN(){
  delay(debounceDel);
  lcd.clear();
  lcd.print("Set Month");
  lcd.setCursor(0,3);
  lcd.print(n);
  
  if(!digitalRead(10)){
    ++n;
  }

  if(!digitalRead(9)){
    --n;
  }

  if(n >= 13){
    n = 1;
  }
}

void displaySD(){
  delay(debounceDel);
  lcd.clear();
  lcd.print("Set DOM");
  lcd.setCursor(0,3);
  lcd.print(d);

  if(!digitalRead(10)){
    ++d;
  }

  if(!digitalRead(9)){
    --d;
  }

  if(d >= 32){
    d = 1;
  }
}

void displaySW(){
  delay(debounceDel);
  lcd.clear();
  lcd.print("Set DOW");
  lcd.setCursor(0,3);

  lcd.print(w);

  if(!digitalRead(10)){
    ++w;
  }

  if(!digitalRead(9)){
    --w;
  }

  if(w >= 8){
    w = 1;
  }
}

void displaySH(){
  delay(debounceDel);
  lcd.clear();
  lcd.print("Set Hour");
  lcd.setCursor(0,3);

  lcd.print(h);

  if(!digitalRead(10)){
    ++h;
  }

  if(!digitalRead(9)){
    --h;
  }

  if(w >= 13){
    w = 1;
  }
}

void displaySM(){
  delay(debounceDel);
  lcd.clear();
  lcd.print("Set Minute");
  lcd.setCursor(0,3);
  lcd.print(m);

  if(!digitalRead(10)){
    ++m;
  }

  if(!digitalRead(9)){
    --m;
  }

  if(m >= 60){
    m = 1;
  }
}

void displayST(){
  lcd.clear(); 
  lcd.print("Set All");
  if(!digitalRead(11)){
    rtc_setTime(s,m,h,w,d,n,y);
  }
}