Weiterleitung von Daten

#include <avr/io.h>

#include "main.h"

#include "suart.h"

#include <avr/power.h>

int i;

char satz[2000];

int main( void ) {

  uart_init();

  uartRx();

  clock_prescale_set(clock_div_1);

  suart_init();

  DDRB = 0x02;

  PORTB = 0x02;

  sei();

  for(i=0; satz[i] != 0; i++) {

    sputs(satz[i]);    

    }

    for (;;) {        // main loop

      sputchar( '-' );

      while (! kbhit());      // wait until byte received

      sputchar (sgetchar () + 1);    // sent byte + 1

    }

}

void uart_init(void) {

    UBRR0H = 0x00;

  UBRR0L = 0x17;    

    UCSR0B = (1<<TXEN0) | (1<<RXEN0);  // UART TX und RX einschalten

    UCSR0C = (1<<USBS0)|(1<<UCSZ01)|(1<<UCSZ00);  // Asynchron 8N2 

}

void uartRx() {

  satz[0] = 1;

  for(i=0; satz[i] != 0; i++) {

      while(!(UCSR0A & (1<<RXC0))) {

    }

    satz[i] = UDR0;                   

  }

}

#include "main.h"

#include "suart.h"

#define BIT_TIME  (u8)((XTAL / BAUD) / PRESCALE)

volatile u8 stx_count;

u8 stx_data;

volatile u8 srx_done;

u8 srx_data;

u8 srx_mask;

u8 srx_tmp;

void suart_init( void )

{

  SBIT(PORTD,STX) = 1;

  // OCR0A = TCNT0 + 1;    // force first compare

  // TCCR0A = 0;        // Default: Normal port operation

  TCCR0B = 1 << CS01 | 1<<CS00;  // clk/64

  // TIFR0 = 1<<ICF1;      // clear pending interrupt

  TIMSK0 = 1 << OCIE0A;    // enable output compare interrupt

  EICRA = 1 << ISC01;      // falling edge

  EIMSK = 1 << INT0;      // enable edge interrupt

  stx_count = 0;        // nothing to sent

  srx_done = 0;            // nothing received

  STXDDR |= 1 << STX;      // TX output

}

u8 sgetchar (void)      // get byte

{

  while (!srx_done);      // wait until byte received

  srx_done = 0;

  return srx_data;

}

ISR (INT0_vect)    // rx start

{

  OCR0B = TCNT0 + (u8)((BIT_TIME * 3) / 2);// scan 1.5 bits after start

  srx_tmp = 0;        // clear bit storage

  srx_mask = 1;        // bit mask

  if( !(SRXPIN & 1<<SRX))  {  // still low

    EIMSK &= ~(1 << INT0);      // disable edge interrupt

    TIMSK0 = 1<<OCIE0A^1<<OCIE0B;  // wait for first bit

}

  TIFR0 = 1<<OCF0B;      // clear pending interrupt ? why does that output compare int occur?

EIFR |= (1 << INTF0);    // clear any pending edge interrupt

}

ISR (TIMER0_COMPB_vect)

{

  u8 in = SRXPIN;      // scan rx line

  // PORTB = 0x00;

  if (srx_mask) {

      if (in & 1 << SRX)

      srx_tmp |= srx_mask;

    srx_mask <<= 1;

    OCR0B += BIT_TIME;      // next bit slice

  } else {

    srx_done = 1;      // mark rx data valid

    srx_data = srx_tmp;      // store rx data

    // TIFR0 = 1<<ICF1;      // clear pending interrupt

    TIMSK0 = 1<<OCIE0A;        // enable tx and wait for start

    EIFR |= (1 << INTF0);    // clear any pending edge interrupt: This hinders the in0-vect from beeing triggerd again just now which may occur by falling edges in the serial data bits

    EIMSK = 1 << INT0;  // reenable edge interrupt

  }

    // PORTB = 0x02;

}

void sputchar (u8 val)      // send byte

{

  while (stx_count);      // until last byte finished

  stx_data = ~val;      // invert data for Stop bit generation

  stx_count = 10;      // 10 bits: Start + data + Stop

}

void sputs (u8 *txt)      // send string

{

  while (*txt)

    sputchar (*txt++);

}

ISR (TIMER0_COMPA_vect)    // tx bit

{

  u8 dout;

  u8 count;

  OCR0A += BIT_TIME;      // next bit slice

  count = stx_count;

  if (count) {

    stx_count = --count;    // count down

    // ??? dout = 1<<COM0A1;      // set low on next compare

    dout = 0;

    if (count != 9) {      // no start bit

      if (!(stx_data & 1))    // test inverted data

        //??? dout = 1<<COM0A1^1<<COM0A0;  // set high on next compare

        dout = 1;

          stx_data >>= 1;      // shift zero in from left

    }

    // TCCR0A = dout;

    // STX = (dout == 0) ? 1 : 0;

    SBIT(PORTD,STX) = dout;

  }

}

#include "main.h"

#include "suart.h"

#include <avr/power.h>

char satz[2000];

int i = 0;

int main( void ) {

  clock_prescale_set(clock_div_1);

  suart_init();

  sei();

  while(1) {

  uartRxChar();

  sputs(satz[i]);  

  }

  for (;;) {        // main loop

    sputchar( '-' );

    while (! kbhit());      // wait until byte received

    sputchar (sgetchar () + 1);    // sent byte + 1

  }

}

void uartRxChar() {

      satz[0] = 1;

  for(i=0; satz[i] != 0; i++) {

      while(!(UCSR0A & (1<<RXC0))) {

    }

    return satz[i] = UDR0;                   

  }

}