#include <avr/io.h>
#include <stdio.h>    // for WinAVR-Compiler
#include <avr/interrupt.h>
#include <avr/signal.h>
#include  <inttypes.h>

#include <Rs232.h> 

#include <avr/pgmspace.h>



//////////////////////////////////////////////////////////////////////////////////////////
// Defines
//////////////////////////////////////////////////////////////////////////////////////////

#define F_CPU            16000000      /* 16Mhz */

// COM Interface
#define COM_BAUD_RATE   38400     /* 38400 baud */


#define COM_BAUD_SELECT (F_CPU/(COM_BAUD_RATE*16l)-1)

#define STX   0x02

#define BARECODE_MUSTER_SIZE  224




#ifndef COM_BUFFER_SIZE
  #define  COM_BUFFER_SIZE  0xF0    // 240 Zeichen
#endif

#ifndef COM_RX_BUFFER
  uint8_t com_rx_buffer[COM_BUFFER_SIZE];
  #define COM_RX_BUFFER &com_rx_buffer[0]
#endif



#define COM_BUFFER_MASK   COM_BUFFER_SIZE - 1 

static volatile uint8_t  * comRxBuffer = (uint8_t*)COM_RX_BUFFER;
static volatile uint8_t    comRxBufferIn;
static volatile uint8_t    comRxBufferOut;


void comInit( void )
{
  
  comRxBufferIn = comRxBufferOut = 0;



  // D-Register initialisieren
  cbi(PORTD,PD0);      // PD0 - RX - Input
  cbi(DDRD,PD0);
  sbi(DDRD,PD1);         // PD1 - TX - Output

    /* enable RxD and ints */
    outp((1<<RXCIE)|(1<<RXEN),UCSRB);  
  outp((1<<RXC),UCSRA);
  //outp((1<<URSEL) | (1<<UCSZ1)  | (1<<UCSZ0),UCSRC);
    /* set baud rate */
    outp((uint8_t)COM_BAUD_SELECT, UBRRL);          
}


////			Zähler			////

enum rc_state  
{
    	rc_start,
    	rc_Length,
    	rc_iLength,
    	rc_Daten_erw01,
    	rc_Daten_erw02,
    	rc_sendLicht,
    	rc_AnDurchlauf,
    	rc_SendeLuecke,
    	rc_sendMasch,
    	rc_Pitch,
    	rc_Brieflaenge,
    	rc_Briefvorderkante,
    	rc_Briefvorderkante_1,
   	rc_barcodeLaenge,
        rc_BarcodeMuster,
        rc_Data,
    	rc_csum,
    	rc_complete
          };




  
/// Übergabe der Empfangenen Daten//////////
void comRecieve( void ) 
{  
  static uint8_t rc_state= rc_start; 
  static uint8_t *ptr;
  static uint8_t data;
  
   // Ein neues Zeichen empfangen ?
   if( comRxBufferIn != comRxBufferOut )
   {
    
     switch ( rc_state )
     {
       case rc_start:
       		if ( comRxBuffer[comRxBufferOut]== STX ) 
       		 {    
        		ptr =(uint8_t *)&myDaten.Start; 
       		    	rc_state++;                  
		}
          break;
      
      case rc_Length:
          	rc_state++;
          break;
      
      case rc_iLength:
          	rc_state++;
          break;
          
      case rc_Daten_erw01:
          	rc_state++;
          break;
      
      case rc_Daten_erw02:
          	rc_state++;
          break;
      
      case rc_sendLicht:
           	rc_state++;
          break;
      
      case rc_AnDurchlauf:
          	rc_state++;
          break;
      
      case rc_SendeLuecke:
           	rc_state++;
          break;
      
      case rc_sendMasch:
                 rc_state++;
          break;
      
      case rc_Pitch:
          	rc_state++;
          break;
      
      case rc_Brieflaenge:
	          rc_state++;
          break;
      
      case rc_Briefvorderkante: 
          	rc_state++;
          break;
      
      case rc_Briefvorderkante_1:
          	rc_state++;
          break;
      
      case rc_barcodeLaenge:
          	rc_state++;
          break;
      
      case rc_BarcodeMuster:
  
        	data = (BARECODE_MUSTER_SIZE-1);
            r	c_state++;  
          break;
      
      case rc_Data:
		data--;
          	if( ! data)
            		{rc_state++;}
          break;
      
      case rc_csum:
          rc_state++;
          break;
      
      default:
        rc_state = rc_start;
        rc_state++;
        
      break;
     }
     
     *(ptr++)= comRxBuffer[comRxBufferOut++];
    comRxBufferOut &= COM_BUFFER_MASK;
       
    if ( rc_state == rc_complete )
      {
        rc_state = rc_start;
      }        
  }    
  
}






SIGNAL(SIG_UART_RECV)      
{
  
  
    comRxBuffer[comRxBufferIn++] = inp(UDR);        /* read byte from UART data buffer */
    comRxBufferIn &= COM_BUFFER_MASK;
}
-----------------------------------------------------------------------------------------------------------------

Die Rs232 Headerdatei:



/*    Telegramm Variablen */

typedef struct 
  {
  
    volatile unsigned char Start;
    volatile unsigned char Length;
    volatile unsigned char iLength;
    volatile unsigned char Daten_erw01;
    volatile unsigned char Daten_erw02;
    volatile unsigned char sendLicht;
    volatile unsigned char AnDurchlauf;
    volatile unsigned char SendeLuecke;
    volatile unsigned char sendMasch;
    volatile unsigned char Pitch;
    volatile unsigned char Brieflaenge;
    volatile unsigned char Briefvorderkante;
    volatile unsigned char Briefvorderkante_1;
    volatile unsigned char barcodeLaenge;
    volatile unsigned char BarcodeMuster[BARECODE_MUSTER_SIZE];
    volatile unsigned char csum;
    volatile unsigned char complete;
    
  }Daten_T; 

volatile Daten_T myDaten;