Cowntdown Timer

#include "Wire.h"

// the I2C address of Tiny RTC
#define DS1307_I2C_ADDRESS 0x68

// define button select time for the timer
#define buttonSelectPin 2
#define buttonHoursPin 3
#define buttonMinPin 4
#define buttonSecPin 5
#define buttonSavePin 6

// for the RTC
byte second, minute, hour, dayOfWeek, dayOfMonth, month, year;

// variable setup the timer
int LED1 = 13;
int Hours=0;
int Min=0;
int Sec=0;

// debounce button
long lastDebounceTime = 0;  // the last time the output pin was toggled
long debounceDelay = 228;    // the debounce time; increase if the output flickers

boolean LED1State = false;
// boolean LED2State = false;

//
long buttonTimer = 0;
long longPressTime = 500;
boolean buttonActive = false;
boolean longPressActive = false;

boolean save_mode = false; // flag for the save button

// set each second read from RTC
unsigned long previousMillis = 0;
const long interval = 1000;

void setup()
{
Wire.begin();
Serial.begin(19200);

//configure pinX as an input and enable the internal pull-up resistor
pinMode(buttonSelectPin, INPUT_PULLUP);
pinMode(buttonHoursPin, INPUT_PULLUP);
pinMode(buttonMinPin, INPUT_PULLUP);
pinMode(buttonSecPin, INPUT_PULLUP);
pinMode(buttonSavePin, INPUT_PULLUP);
pinMode(13, OUTPUT);
setDateDs1307(); //Set current time;
}

void loop()
{
 // read from RTC each second
 unsigned long currentMillis = millis();
 if (currentMillis - previousMillis >= interval)
  {
   previousMillis = currentMillis;
   getDateDs1307(); //get the time data from tiny RTC

   counter_down(); // need countdown only if the time setup
  }
  read_button();
}

void counter_down()
{
 // ???
}

void read_button()
{
 if (digitalRead(buttonSelectPin) == LOW)
 {
  if (buttonActive == false)
  {
   buttonActive = true;
   buttonTimer = millis();
  }
  if ((millis() - buttonTimer > longPressTime) && (longPressActive == false))
  {
    // long press on the button activate the LED1
   longPressActive = true;
   LED1State = !LED1State;
   digitalWrite(LED1, LED1State);
  }
 }
  else
  {
   if (buttonActive == true)
   {
    if (longPressActive == true)
    {
     longPressActive = false;
    }
    else
    {
     // LED2State = !LED2State;
     // digitalWrite(LED2, LED2State);
    }
     buttonActive = false;
   }
  }
   // when the LED1 is ON, the long press is activate, enter the setup loop
  while(LED1State == HIGH)
  {
   setup_timer(); // set the timer, read from button
   if(save_mode == true)
   {
    save_mode = false;
    LED1State = !LED1State;
    digitalWrite(LED1, LED1State);
    break;
   }
  }
}

// read button with debounce
void setup_timer()
{
 if ( (millis() - lastDebounceTime) > debounceDelay)
 {
  if (digitalRead(buttonHoursPin) == LOW)
  {
   Hours++;
   if (Hours >= 24) Hours=0;
   Serial.println(Hours);
   lastDebounceTime = millis();
  }
  if (digitalRead(buttonMinPin) == LOW)
  {
   Min++;
   if (Min >= 60) Min=0;
   Serial.println(Min);
   lastDebounceTime = millis();
  }
  if (digitalRead(buttonSecPin) == LOW)
  {
   Sec++;
   if (Sec >= 60) Sec=0;
   Serial.println(Sec);
   lastDebounceTime = millis();
  }
  if (digitalRead(buttonSavePin) == LOW)
  {
   save_mode = true;
  }
 }
}

// Convert normal decimal numbers to binary coded decimal
byte decToBcd(byte val)
{
 return ( (val/10*16) + (val%10) );
}
// Convert binary coded decimal to normal decimal numbers
byte bcdToDec(byte val)
{
 return ( (val/16*10) + (val%16) );
}
// Function to set the currnt time, change the second&minute&hour to the right time
void setDateDs1307()
{
 second =45;
 minute = 29;
 hour = 13;
 dayOfWeek = 2;
 dayOfMonth =18;
 month =9;
 year= 12;
 Wire.beginTransmission(DS1307_I2C_ADDRESS);
 Wire.write(decToBcd(0));
 Wire.write(decToBcd(second)); // 0 to bit 7 starts the clock
 Wire.write(decToBcd(minute));
 Wire.write(decToBcd(hour)); // If you want 12 hour am/pm you need to set
 // bit 6 (also need to change readDateDs1307)
 Wire.write(decToBcd(dayOfWeek));
 Wire.write(decToBcd(dayOfMonth));
 Wire.write(decToBcd(month));
 Wire.write(decToBcd(year));
 Wire.endTransmission();
}
// Function to gets the date and time from the ds1307 and prints result
void getDateDs1307()
{
 // Reset the register pointer
 Wire.beginTransmission(DS1307_I2C_ADDRESS);
 Wire.write(decToBcd(0));
 Wire.endTransmission();
 Wire.requestFrom(DS1307_I2C_ADDRESS, 7);
 second = bcdToDec(Wire.read() & 0x7f);
 minute = bcdToDec(Wire.read());
 hour = bcdToDec(Wire.read() & 0x3f); // Need to change this if 12 hour am/pm
 dayOfWeek = bcdToDec(Wire.read());
 dayOfMonth = bcdToDec(Wire.read());
 month = bcdToDec(Wire.read());
 year = bcdToDec(Wire.read());
  Serial.print(hour, DEC);
 Serial.print(":");
 Serial.print(minute, DEC);
 Serial.print(":");
 Serial.print(second, DEC);
 Serial.print(" ");
 Serial.print(month, DEC);
 Serial.print("/");
 Serial.print(dayOfMonth, DEC);
 Serial.print("/");
 Serial.print(year,DEC);
 Serial.print(" ");
 Serial.println();
 //Serial.print("Day of week:");
}