#define F_CPU 7372800UL

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

static uint16_t delayCnt;
static uint16_t step = 5;

void delay(uint16_t t){
	uint8_t i;

	for(i=0; i<t; i++){
		_delay_ms(1);
	}
}

void aktivnost(){

	PORTA = PORTA << 1;
	if(PORTA != 0xfe && PORTA != 0b11111100){
		PORTA |= 0x01;
	}

}

int main(void){

	PORTA = 0xff;
	DDRA = 0xff;

	DDRB = 0;
	PORTB = _BV(0) | _BV(1);

	while (1) {

		if(bit_is_clear(PINB, 0)){
			if(delayCnt + step < 500)
				delayCnt += step;
		}
		if(bit_is_clear(PINB, 1)){
			if(delayCnt + step > 100)
				delayCnt -= step;
		}

		aktivnost();
		delay(delayCnt);

	}
}