/*Program code written for WinAVR toolset:
-------------------------*/

#include <avr\io.h>

int main(void) {
	//Port D pins as input
	DDRD=0x00;
	//Enable internal pull ups
	PORTD=0xFF;
	//Set PORTB1 pin as output
	DDRB=0xFF;

	//TOP=ICR1;
	//Output compare OC1A 8 bit non inverted PWM
	//Clear OC1A on Compare Match, set OC1A at TOP
	//Fast PWM
	//ICR1=20000 defines 50Hz PWM

	ICR1=20000;
	TCCR1A|=(0<<COM1A0)|(1<<COM1A1)|(0<<COM1B0)|(0<<COM1B1)|
	(0<<FOC1A)|(0<<FOC1B)|(1<<WGM11)|(0<<WGM10);
	TCCR1B|=(0<<ICNC1)|(0<<ICES1)|(1<<WGM13)|(1<<WGM12)|
	(0<<CS12)|(1<<CS11)|(0<<CS10);

	//start timer with prescaler 8

	for (;;) {
		if(bit_is_clear(PIND, 0)){
			//increase duty cycle
			OCR1A+=10;
			loop_until_bit_is_set(PIND, 0);
		}

		if(bit_is_clear(PIND, 1)) {
			//decease duty cycle
			OCR1A-=10;
			loop_until_bit_is_set(PIND, 1);
		}
	}
}

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