Svenska ElektronikForumet

Kod: Markera allt

#include <avr/interrupt.h>
#include <avr/delay.h>
#include <avr/signal.h>
#include <inttypes.h>

void OSCCAL_calibration(void);

typedef volatile unsigned char BYTE;

BYTE dutyCycle = 0;
BYTE tickCount = 0x00;

int main(void)
{
	OSCCAL_calibration();
	DDRD = 0xFF;
	// Increase the oscillator to 2 Mhz for timer:
	CLKPR = (1<<CLKPCE);        // set Clock Prescaler Change Enable
    // set prescaler = 4, Inter RC 8Mhz / 4 = 2Mhz
	CLKPR = (1<<CLKPS1);
	
	// Initialize Timer0.
    // Enable timer0 compare interrupt
	TIMSK0 = (1<<OCIE0A);

	// Sets the compare value
	OCR0A = 1;
	
	// Set Clear on Timer Compare (CTC) mode, CLK/8 prescaler
	TCCR0A = (1<<WGM01)|(0<<WGM00)|(1<<CS01);
	
	while(1)
	{
		for(int i = 1; i <= 255; i++)
		{
			dutyCycle = i;
			_delay_loop_2(10000);
		}	
			
		for(int i = 254; i > 1; i--)
		{
			dutyCycle = i;
			_delay_loop_2(10000);
		}
	}
	
	return 0;
}

SIGNAL(SIG_OUTPUT_COMPARE0)
{
	if (tickCount == 0) {
	   PORTD = 0xFF;
	}

	if (tickCount == dutyCycle) {
	   PORTD = 0x00;
	}
	
	tickCount++;
}