#include <avr/io.h>
#include <avr/interrupt.h>
#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#ifndef OCR1A
#define OCR1A OCR1  // 2313 support
#endif

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


#define F_CPU 8000000UL
#define BAUD      9600UL
#define UBRR_BAUD   ((F_CPU/(16L*BAUD))-1)

//LED Port Initialisierung
#define LED_DDR         DDRA								
#define LED_PORT        PORTA								
#define LED0            0									
#define LED1            1
#define LED2            2



//Timer Einstellung Variablen
#define DEBOUNCE  256L    
#define uchar unsigned char
#define uint unsigned int
uchar prescaler;
uchar volatile std;
uchar volatile min;
uchar volatile sek;     


unsigned int counter = 0;
unsigned int gestellt = 0;         


//Variablen für USART (RS232) Übertragung
char buffer[10];
volatile uint8_t habekommando;



//Initialisierung USART
void uart_init(void) 
{ 
												
UBRRH = (uint8_t) (UBRR_BAUD>>8); 
UBRRL = (uint8_t) (UBRR_BAUD & 0xFF);  
UCSRB = (1<<TXEN) | (1<<RXEN)|(1<<RXCIE); 												
UCSRC = (1<<URSEL)|(1<<UCSZ1)|(1<<UCSZ0); 
}  

//ISR Interrupt für USART Empfang
ISR(USART_RX_vect) 
	

	{  
	static uint8_t position=0;
	uchar c = UDR;



	if (c == '#') 		
	{
	buffer[position] = '\0';
	habekommando++;
	position = 0;
	 
} 

else {

	buffer[position] = c;
	position++;

     }
}

//Initialisierung für das Senden über USART
void uart_putc(char f )
{
  while (!(UCSRA & (1<<UDRE)))   //warten bis Senden möglich                   
    {
    }	

  UDR = f;

}


void uart_puts( const char* String )
{
  while( *String )
    uart_putc( *String++ );
}


//Timerinterrupt für genauen Sekundentakt
ISR (TIMER1_COMPA_vect)
{
/************************************************************************/
/*      Insert Key Debouncing Here      */
/************************************************************************/

#if F_CPU % DEBOUNCE
  OCR1A = F_CPU / DEBOUNCE - 1;    // compare DEBOUNCE - 1 times
#endif
  if( --prescaler == 0 )
  {
    prescaler = (uchar)DEBOUNCE;
    sek++;        // exact one second over
#if F_CPU % DEBOUNCE      // handle remainder
    OCR1A = F_CPU / DEBOUNCE + F_CPU % DEBOUNCE - 1; // compare once per second
#endif
  }
 

 	{ 
      if(sek >= 60)
	  { 
	  min++;                                                 
      	  sek = 0;
	  }		                  
      if(min >= 60)
	  {	
	  std++;					        
      	  min = 0;
	  }			                
      if(std >= 24)
	  {   					 
       	  std = 0;              
      	  }
    }
      
    
  }



//Hauptprogramm

int main( void )
{
  LED_PORT = 0xFF;											//LED_PORT wird auf 1 gesetzt
  LED_DDR = 0xFF;
  
  

  TCCR1B = 1<<WGM12^1<<CS10;    // divide by 1
          						// clear on compare
  OCR1A = F_CPU / DEBOUNCE - 1;
  TCNT1 = 0;
  sek = 0;
  prescaler = (uchar)DEBOUNCE;

  TIMSK = 1<<OCIE1A;
  uart_init();
  sei();
 

  
  while(1)
  
  {
		if (habekommando == 2) 
  		{
		sscanf(buffer,"%d:%d:%d", &std, &min, &sek);
		habekommando = 0;
		}
		               
  
  }
}