/*
 * PWM_extra_opdracht_cod_v0.c
 *
 * Created: 25-5-2016 16:40:52
 *  Author: dorien.van.ettekoven
 */ 

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

unsigned int i=0;

void ioinit()//define ports and pins as input or output 
{
	DDRA &= (1<<PA0); //PinA0 is input, switch A0 will be used as input to start PWM cycle 
	DDRB |= (1<<PB3); //PortB (OC0 = PB3) will be used as output for PWM
}

void init_pwm() //initialize PWM arrays
{
	if (PINA0 & (1<<PA0) ==1) //when switch A0 is pressed the PWM cycle will start 
	{
		ISR (TIMER0_COMP_vect); //Interrupt Service Routine Timer0 executed 
		{
			for(i=0;i<255;i++) //for-statement to brighten up LED using PWM 
			{
			OCR0 = 0; //increase PWM, PWM goes from 0 to 255
			return;
			}
		}
	}
} 
int main ()
{
	TCCR0= (1<<WGM12 | 1<<WGM10 | 1<<CS00 | 1<<COM01); //Timer Counter0 Control Register. Timer 0 on FAST PWM mode, non inverted, no prescaler
	TIMSK |= (1<<OCIE0);//Timer Interrupt Mask Register, enable interrupts 
	sei(); //enable global interrupts 
	
}