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Kod: Markera allt

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

#define F_CPU 8000000
#define USART_BAUDRATE 9600 
#define BAUD_PRESCALE (((F_CPU / (USART_BAUDRATE * 16UL))) - 1) 

int main (void) 
{ 
   DDRC = 0x00;
   DDRB = 0xFF;
   UCSRC = (1<<URSEL)|(0<<UMSEL)|(0<<UPM1)|(0<<UPM0)|(0<<USBS)|(1<<UCSZ1)|(1<<UCSZ0);
   UCSRB = (1<<RXEN)|(1<<TXEN)|(1<<TXCIE)|(1<<RXCIE)|(1<<UCSZ2); 

   UBRRL = BAUD_PRESCALE; // Load lower 8-bits of the baud rate value into the low byte of the UBRR register 
   UBRRH = (BAUD_PRESCALE >> 8); // Load upper 8-bits of the baud rate value into the high byte of the UBRR register 

   for (;;) // Loop forever 
   { 

  
      while ((UCSRA & (1 << UDRE)) == 0) {}; // Do nothing until UDR is ready for more data to be written to it 
      
      UCSRB |= (1<<TXB8); 
      UDR = 0x02;
      
      while ((UCSRA & (1 << UDRE)) == 0) {}; 
      PORTB = PINC;
      UCSRB &= ~(1<<TXB8); 
      UDR = PINC; 
   }    

}

Kod: Markera allt

#include <avr/io.h> 
#include <avr/interrupt.h> 

#define bit_on(BYTE, BIT)  BYTE |= 1 << BIT
#define bit_off(BYTE, BIT) BYTE &= ~(1 << BIT)

#define F_CPU 8000000
#define USART_BAUDRATE 9600 
#define BAUD_PRESCALE (((F_CPU / (USART_BAUDRATE * 16UL))) - 1) 
#define rx_address 0x02


int main (void) 
{ 
   DDRB = 0xFF;
   DDRC = 0xFF;
   UBRRL = BAUD_PRESCALE; // Load lower 8-bits of the baud rate value into the low byte of the UBRR register 
   UBRRH = (BAUD_PRESCALE >> 8); // Load upper 8-bits of the baud rate value into the high byte of the UBRR register 

   UCSRC = (1<<URSEL)|(0<<UMSEL)|(0<<UPM1)|(0<<UPM0)|(0<<USBS)|(1<<UCSZ1)|(1<<UCSZ0);
   UCSRB = (1<<RXEN)|(1<<TXEN)|(1<<RXCIE)|(1<<TXCIE)|(1<<UCSZ2); 
   UCSRA |= (1<<MPCM); 
    sei();
    PORTB = 0xFF;
    PORTC = 0x00;
   for (;;) // Loop forever 
   { 
         // Do nothing - echoing is handled by the ISR instead of in the main loop 

   }    
} 

ISR(USART_RXC_vect) 
{ 
   unsigned char inData; 
   inData = UDR;    //Read data register    
   if(UCSRB & (1<<RXB8)) //Address frame? 
   { 
      if((inData) == rx_address)    //Verify address 
      { 
         UCSRA &= ~(1<<MPCM);//Disable MPCM filtering 
         bit_on(PORTC,4);
      } 
      else // not our address, ignore any data 
      { 
         UCSRA |= (1<<MPCM);//Enable MPCM filtering 
         bit_off(PORTC,4);
 
      } 
    bit_off(PORTC,3);
   } 
   else                   //Data Frame received 
   { 
        bit_on(PORTC,3);
        PORTB = inData; 
        UCSRA |= (1<<MPCM); //Enable MPCM 

   } 
} 

Kod: Markera allt

  if(UCSRA & (1<<MPCM)) //Address frame? 

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ISR(USART_RXC_vect) 
{ 
 unsigned char status, control, inData; 
   status=UCSRA;    //Read register A 
   control=UCSRB;   //Read register B -- incl. RXB8 
   inData = UDR;    //Read data register      
   if(control & (1<<RXB8)) //Address frame? 
   { 
      if((inData) == rx_address)    //Verify address 
      { 
         UCSRA &= ~(1<<MPCM);//Disable MPCM filtering 
         bit_on(PORTC,4);
      } 
      else // not our address, ignore any data 
      { 
         UCSRA |= (1<<MPCM);//Enable MPCM filtering 
         bit_off(PORTC,4);
 
      } 
    bit_off(PORTC,3);
   } 
   else                   //Data Frame received 
   { 
        bit_on(PORTC,3);
        PORTB = inData; 
        UCSRA |= (1<<MPCM); //Enable MPCM 

   } 
}