DS1302 nur alle 2s gültiges Signal?

Hallo zusammen,

ich habe keine Ideen mehr. Vielleicht könnt ihr mir helfen? Ich möchte 
einfach nur mit einem Mega32 die Sekunden aus dem DS1302 auslesen. Das 
gelingt mir allerdings nur alle 2s korrekt. Was mache ich falsch? Bin 
dankbar für jede Antwort!

Gruß

enhape

Anbei der Code, gefolgt von der ds1302.h (dankend aus dem Forum bezogen)

///////////////////////////////////////////////////////////////////
#include <avr/io.h>
#include <util/delay.h>

#include "ds1302.h"


#ifndef F_CPU
#define F_CPU 1000000
#endif




// Prototypen
uint8_t Read_DS1302(uint8_t);




int main()
{

  //Ports initialisieren:
    DDRC = 0xFF; // Port C auf Ausgang

  uint8_t temp2;


  //RTC initialisieren
   RTC_Init();


    while (1)
    {
    _delay_ms(1);
    temp2 = Read_DS1302(0x81);
    PORTC = ~temp2;
  }
}


//**************************************
// Write
//**************************************
void Write( char cmd )
{

  uint8_t n;

  RTC_DATA_LINE_IS_OUTPUT();
  _delay_ms(1);
  for (n = 0; n < 8; n++)
  {
    if (CheckBit(cmd,n))
    {
    RTC_DATA_HIGH();
    }
  else
  {
      RTC_DATA_LOW();
    }
  _delay_ms(1);
  RTC_CLK_HIGH();
    _delay_ms(1);
  RTC_CLK_LOW();
  _delay_ms(1);
  }
  RTC_DATA_LINE_IS_INPUT();
}

//**************************************
// Write_DS1302
//**************************************
void Write_DS1302( uint8_t cmd, uint8_t data )
{
  RTC_RESET_HIGH();
  Write(cmd);
  Write(data);
  RTC_RESET_LOW();
}

//***************************************
// Read
//***************************************
uint8_t Read( void )
{

   uint8_t n, d, data;
   data = 0x00;


   for(n = 0; n < 8; n++)
   {
     d = CHECK_RTC_DATA();
     data = (data >> 1);
     if (d)
   {
       data |= 0x80;
   }
   _delay_ms(1);
     RTC_CLK_HIGH();
     _delay_ms(1);
     RTC_CLK_LOW();
     _delay_ms(1);
   }
   return data;
}

//***************************************
// Read_DS1302
//***************************************
uint8_t Read_DS1302(uint8_t cmd)
{
  uint8_t data;
  RTC_RESET_HIGH();
  _delay_ms(1);
  Write(cmd);
  _delay_ms(1);
  data = Read();
  _delay_ms(1);;
  RTC_RESET_LOW();
  _delay_ms(1);;
  return data;
}




//*************************
// RTC_Init         (called from Main-Init)
//*************************
void RTC_Init(void )
{ uint8_t data;

  RTC_RESET_LOW();

  RTC_DATA_LINE_IS_INPUT();
  NOP();
  NOP();
  RTC_CLK_LOW();
  NOP();
  NOP();

  Write_DS1302(CONTROL_REGISTER, UNPROTECT);
  data = Read_DS1302( 0x81);
  if (CheckBit(data,7))               // if bit 7 is high, Clock is 
stopped
  {  Write_DS1302( 0x80, 0x00);
  }
  Write_DS1302(CONTROL_REGISTER, PROTECT);

}



////////////////////////////////////////////////////////////////////////
//ds1302.h:


#ifndef  _RTC_H
#define  _RTC_H 1

#define BYTE  unsigned char
#define TRUE                 (BYTE)1
#define FALSE                (BYTE)0
#define NOP()      asm("nop")

#define SetBit(ADRESS,B)         ((ADRESS) |=  (1<<(B)))
#define ClearBit(ADRESS,B)       ((ADRESS) &= ~(1<<(B)))
#define CheckBit(ADRESS,B)       (BYTE)((ADRESS) &   (1<<(B)))
#define ToggleBit(ADDRESS,BIT)   ((ADDRESS) ^= (1<<BIT))

//=================================================
// je nachdem, an welchem Port DS1302 haengt,
// muessen diese Werte angepasst werden
#define RTC_CLK             0
#define RTC_DATA            1
#define RTC_RES             2

#define RTC_CLK_LOW()             ClearBit(PORTA,RTC_CLK)
#define RTC_CLK_HIGH()            SetBit(PORTA,RTC_CLK)
#define RTC_DATA_LOW()            ClearBit(PORTA,RTC_DATA)
#define RTC_DATA_HIGH()           SetBit(PORTA,RTC_DATA)
#define CHECK_RTC_DATA()          CheckBit(PINA,RTC_DATA)
#define RTC_RESET_LOW()           ClearBit(PORTA,RTC_RES)
#define RTC_RESET_HIGH()          SetBit(PORTA,RTC_RES)
#define RTC_DATA_LINE_IS_OUTPUT() SetBit(DDRA,   RTC_DATA)
#define RTC_DATA_LINE_IS_INPUT()  ClearBit(DDRA, RTC_DATA)
// Ende der Anpassung
//=================================================

#define RTC_RAM   1
#define RTC_CLOCK 0

#define RTC_SEC   0
#define RTC_MIN   1
#define RTC_HRS   2
#define RTC_DAY   3
#define RTC_MONTH 4
#define RTC_DOW   5          // day of week (1 = Mon)
#define RTC_YEAR  6


#define CONTROL_REGISTER 0x8E
#define PROTECT   0x80
#define UNPROTECT 0x00

void RTC_Init(void );
void RTC_SetTime( void );
void RTC_GetTime( void );
void RTC_Unprotect( void );
void RTC_Protect( void );
BYTE RTC_Ctrl( void );
#endif