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// interrupt based light flashing program for atmel mega8l

// 

// Craig Limber, July 2004

//

#include <avr/interrupt.h>

#include <avr/io.h>

//#include <avr/signal.h>

//-----------------------------------------------------------------------------

ISR(TIMER1_COMPA_vect)

{

  static uint8_t ledon;

  if (ledon)

  {

    ledon = 0;

    PORTB |= _BV(PB2);

  }

  else

  {

    ledon = 1;

    PORTB &= ~_BV(PB2);

  }

}

//-----------------------------------------------------------------------------

void main()

{

  DDRB = _BV(PB2);     // enable output

  TIMSK = _BV(OCIE1A);

  TCCR1B = _BV(CS12)    // 256 prescale

         | _BV(WGM12);  // CTC mode, TOP = OCR1A

  OCR1A = 15625;        // count up to TOP   1hz with 8 meg system clock

  sei();

 int i=0; 

 while (1)

 {

 i++;

 }   

}

avr-gcc -std=gnu99 -mmcu=atmega8 $1 -Os -o $1.hex -Wall

avrdude -V -U flash:w:$1.hex -cavrisp -b19200 -p m8 -P /dev/ttyUSB0