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

#define UP	0
#define DOWN	1

int main(void)
{
	
	/* Init LEDs */
	DDRD |= (1 << PIND6);
	DDRD |= (1 << PIND7);
	DDRB |= (1 << PINB0);

	/* Init push button */
	DDRC &= ~(1 << PINC5);
	PORTC |= (1 << PINC5);
	
	uint8_t active=0;
	uint8_t direction=DOWN;
	uint8_t btn_last=1;
	uint8_t counter=0;
		
    while(1)
    {

		if ((btn_last)&&(!(PINC & (1<<PINC5)))) {
			++direction;
			direction%=2; 
		}
		btn_last=(PINC & (1<<PINC5));

		if (counter++ > 10) {

			counter=0;

			if (direction==UP)
				++active;
			else 
				--active;

			switch(active) {
				case 2:
					PORTD &= ~(1 << PIND6);
					PORTD |= (1 << PIND7);
					PORTB &= ~(1 << PINB0);
					break;
				case 3: 
					PORTD |= (1 << PIND6);
					PORTD &= ~(1 << PIND7);
					PORTB &= ~(1 << PINB0);
					break;
				default: 
					PORTD &= ~(1 << PIND6);
					PORTD &= ~(1 << PIND7);
					PORTB |= (1 << PINB0);
					active=(direction==UP)?1:4;
			}
		}
		
		_delay_ms(50);
    }
}