//binary clock (c) 2005 gregi
//last change: 25.02.2005, 20:00
// features for now:
//	* display and increment current time
// 	* set time/date via pushbuttons
//	* switch between date/time
//	* increment date (months, switching years)
// features to do:
//	* set alarm time?! (with buzzer? PBx?)
//		(save to eeprom)
// 	* boot-up-effects (self test)

// io configurations, avr-libc
#include <avr/io.h>
#include <avr/signal.h>
#include <avr/interrupt.h>

//#define DEBUG 1

// Multiplex-Pins
#define MPLEX_HOURS 0x04
#define MPLEX_MINUTES 0x02
#define MPLEX_SECONDS 0x01
// needed to clear all multiplex pins (every cycle)
#define MPLEX_CLEAR 0xF8

//port definitions
#define CLKDATA PORTD
#define CLKCTRL PORTB

//compatibility defines for 2313 (timer routine by peter danegger)
#ifndef OCR1A
#define OCR1A OCR1	// 2313 support
#endif

#ifndef WGM12
#define WGM12 CTC1	// 2313 support
#endif

#define XTAL		10000000L	// nominal value

#define DEBOUNCE	256L		// debounce clock (256Hz = 4msec)


typedef unsigned char u08;

// our time structure, year could need an int, but we can't display it.
typedef struct _Time {
	u08 seconds;
	u08 minutes;
	u08 hours;
	u08 day;
	u08 month;
	u08 year;
} Time;

// global variables
u08 prescaler;

// clock
Time meineuhr;

// display clock/date
u08 mode;

// set mode
u08 set;
// step (digit)
u08 step;

// release key flag
u08 release;
// count registers (debounce)
u08 tempset;
u08 tempinc;

// multiplex
u08 mplex_clk;


//update: this function is called every second to update the clock/date
void update(Time *meineuhr)
{
	if(++meineuhr->seconds == 60)
	{
		meineuhr->seconds = 0;
		if(++meineuhr->minutes == 60)
		{
			meineuhr->minutes = 0;
			if(++meineuhr->hours == 24)
			{
				meineuhr->hours = 0;
				if(++meineuhr->day == 32)
				{
					meineuhr->month++;
					meineuhr->day = 1;
				}
				else if(meineuhr->day == 31)
				{
					if((meineuhr->month == 4 || 6 || 9 || 11))
					{
						meineuhr->month++;
						meineuhr->day = 1;
					}
				}
				else if(meineuhr->day == 30)
				{
					if(meineuhr->month == 2)
					{
						meineuhr->month++;
						meineuhr->day = 1;
					}
				}
				else if(meineuhr->day == 29)
				{
					if((meineuhr->month == 2) && (meineuhr->year % 4))
					{
						meineuhr->month++;
						meineuhr->day = 1;
					}
				}
				if(meineuhr->month == 13)
				{
					meineuhr->month = 1;
					meineuhr->year++;
				}
			}
		}
	}
}

#ifdef DEBUG
void print(Time *meineuhr)
{
	printf("%02i:%02i:%02i\n",meineuhr->hours, meineuhr->minutes, meineuhr->seconds);
}
#endif

// this function sets the hour-multiplexline and the calculated (BCD) hour-databits.
void OutputHours(Time *meineuhr)
{
	u08 myhours;
	myhours = meineuhr->hours / 10; // tens!
	myhours <<= 4;
	myhours |= meineuhr->hours % 10; // ones
#ifdef DEBUG
	printf("%2X\n",myhours);
#endif
	//output to port
	CLKCTRL &= MPLEX_CLEAR;
	CLKCTRL |= MPLEX_HOURS;
	CLKDATA = myhours;
}
// this function sets the minutes-multiplexline and the calculated (BCD) minutes-databits.
void OutputMinutes(Time *meineuhr)
{
	u08 myminutes;
	myminutes = meineuhr->minutes / 10; //tens
	myminutes <<= 4;
	myminutes |= meineuhr->minutes % 10; //ones
#ifdef DEBUG	
	printf("%02X\n",myminutes);	
#endif
	//output to port
	CLKCTRL &= MPLEX_CLEAR;
	CLKCTRL |= MPLEX_MINUTES;
	CLKDATA = myminutes;
}
// this function sets the minutes-multiplexline and the calculated (BCD) minutes-databits.
void OutputSeconds(Time *meineuhr)
{
	u08 myseconds;
	myseconds = meineuhr->seconds / 10; //tens
	myseconds <<= 4;
	myseconds |= meineuhr->seconds % 10; //ones
#ifdef DEBUG
	printf("%02X\n",myseconds); 	
#endif
	//output to port
	CLKCTRL &= MPLEX_CLEAR;
	CLKCTRL |= MPLEX_SECONDS;
	CLKDATA = myseconds;
}
// this function sets the hours-multiplexline and the calculated (BCD) days-databits.
void OutputDays(Time *meineuhr)
{
	u08 mydays;
	mydays = meineuhr->day / 10; //tens
	mydays <<= 4;
	mydays |= meineuhr->day % 10; //ones
	
	CLKCTRL &= MPLEX_CLEAR;
	CLKCTRL |= MPLEX_HOURS;
	CLKDATA = mydays;
}
// this function sets the minutes-multiplexline and the calculated (BCD) months-databits.
void OutputMonths(Time *meineuhr)
{
	u08 mymonths;
	mymonths = meineuhr->month / 10; //tens
	mymonths <<= 4;
	mymonths |= meineuhr->month % 10; //ones
	
	CLKCTRL &= MPLEX_CLEAR;
	CLKCTRL |= MPLEX_MINUTES;
	CLKDATA = mymonths;
}
// this function sets the seconds-multiplexline and the calculated (BCD) years-databits.
void OutputYears(Time *meineuhr)
{
	u08 myyears;
	myyears = meineuhr->year / 10; //tens
	myyears <<= 4;
	myyears |= meineuhr->year % 10; //ones
	
	CLKCTRL &= MPLEX_CLEAR;
	CLKCTRL |= MPLEX_SECONDS;
	CLKDATA = myyears;
}

//timer compare interrupt, every 4 ms
SIGNAL (SIG_OUTPUT_COMPARE1A)
{
#if XTAL % DEBOUNCE
  OCR1A = XTAL / DEBOUNCE - 1;		// compare DEBOUNCE - 1 times
#endif
  if( --prescaler == 0 ){
    prescaler = (u08)DEBOUNCE;
    if(set != 1)
    	update(&meineuhr);				// exact one second over
#if XTAL % DEBOUNCE			// handle remainder
    OCR1A = XTAL / DEBOUNCE + XTAL % DEBOUNCE - 1; // compare once per second
#endif
  }

if(set == 1)	// set mode!
{
switch(step)
{
	case 1:
	case 2:
		OutputHours(&meineuhr);
		break;
	case 3:
	case 4:
		OutputMinutes(&meineuhr);
		break;
	case 5:
	case 6:
		OutputSeconds(&meineuhr);
		break;
	case 7:
	case 8:
		OutputDays(&meineuhr);
		break;
	case 9:
	case 10:
		OutputMonths(&meineuhr);
		break;
	case 11:
	case 12:
		OutputYears(&meineuhr);
		break;
	case 13:
		set = 0;
		step = 0;
		break;
	default:
		break;
		
}
}
else		//display mode
{
  switch(mplex_clk)
  {
  case 0:
  	(mode) ? OutputHours(&meineuhr) : OutputDays(&meineuhr);
	break;
  case 1:
	(mode) ? OutputMinutes(&meineuhr) : OutputMonths(&meineuhr);
	break;
  case 2:
	(mode) ? OutputSeconds(&meineuhr) : OutputYears(&meineuhr);
	break;
  }
}  
  mplex_clk++;
  if(mplex_clk == 3)
  	mplex_clk = 0;
	
// key debouncing and input routine
if(!(PINB & (1 << PB3)))	// set key pressed?
{
	tempset++;
}
else
{
	tempset = 0;
	//set = 0;
	release = 1;
}

if(!(PINB & (1 << PB4)))		// inc key pressed?
{
		tempinc++;
}
else
{
	tempinc = 0;
	release = 1;
}

	
	if(tempset == 25)	// set key debounced and pressed
	{
		if(set && release)
		{
			step++;		//next step (set!)
		}
		else
		{
			mode = ~mode;	//switch between clock and date
		}
	}
	if(tempset == 200)	// set key pressed really long (800ms)
	{
		set = 1;	// we are in set-mode	
		step = 1;	
		release = 0;
		//clear time
// 		meineuhr.hours = 0;
// 		meineuhr.minutes = 0;
// 		meineuhr.seconds = 0;
// 		meineuhr.day = 0;
// 		meineuhr.month = 0;
// 		meineuhr.year = 0;

	}
	if(tempinc == 25)	// increment key pressed
	{
	switch(step)
	{
	case 1:	//hours tens
		
		if(meineuhr.hours >= 20)
			meineuhr.hours -= 20;
		else
			meineuhr.hours += 10;
		break;
	case 2:	//hours ones
		if((meineuhr.hours % 10) == 9)
			meineuhr.hours -= 9;
		else
			meineuhr.hours++;
		break;
		
	case 3:	//minutes tens
		
		if(meineuhr.minutes >= 50)
			meineuhr.minutes -= 50;
		else
			meineuhr.minutes += 10;
		break;
	case 4: //minutes ones
		if((meineuhr.minutes % 10) == 9)
			meineuhr.minutes -= 9;
		else
			meineuhr.minutes++;
		break;
		
	case 5:	//seconds tens
		
		if(meineuhr.seconds >= 50)
			meineuhr.seconds -= 50;
		else
			meineuhr.seconds += 10;
		break;
	case 6:	//seconds ones
		if((meineuhr.seconds % 10) == 9)
			meineuhr.seconds -= 9;
		else
			meineuhr.seconds++;
		break;	
		
	case 7: //day tens
		
		if(meineuhr.day >= 30)
			meineuhr.day -= 30;
		else
			meineuhr.day += 10;
		break;
	case 8:	//day ones
		if((meineuhr.day % 10) == 9)
			meineuhr.day -= 9;
		else
			meineuhr.day++;
		break;			
	
	case 9: //month tens
		
		if(meineuhr.month >= 10)
			meineuhr.month -= 10;
		else
			meineuhr.month += 10;
		break;
	case 10:	//month ones
		if((meineuhr.month % 10) == 9)
			meineuhr.month -= 9;
		else
			meineuhr.month++;
		break;			
	case 11:	//year tens
		
		if(meineuhr.year >= 70)
			meineuhr.year -= 70;
		else
			meineuhr.year += 10;
		break;
	case 12:	// year ones
		if((meineuhr.year % 10) == 9)
			meineuhr.year -= 9;
		else
			meineuhr.year++;
		break;			
	default:
		break;
	}
	}
	
		
}
void Init(void)
{
	/* port configuration */
	DDRD = 0xFF;
	DDRB = 0x07;
	
	PORTB = 0xFF;	//pullup resistors
	
	/* timer 1 config */
	TCCR1B = 1<<WGM12^1<<CS10;		// divide by 1
					// clear on compare
	OCR1A = XTAL / DEBOUNCE - 1;
	TCNT1 = 0;
	
	prescaler = (u08)DEBOUNCE;
	
	TIMSK = 1<<OCIE1A;
	
	mode = 0xFF;	// show clock
	set = 0;
	
	tempset = 0;
	tempinc = 0;
	
	mplex_clk = 0;
	
	
	/* enable interrupts */
	sei();
}


void main(void)
{
	//static definitions (power up time/date)
	//we should read this from eeprom once
	meineuhr.year = 05;
	meineuhr.month = 1;
	meineuhr.day = 1;

	meineuhr.hours =    5;
	meineuhr.minutes = 10;
	meineuhr.seconds =  5;
	
	Init();
	
	for(;;)		// endless loop, should be empty!
	{	
	}
}