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

#define SET(REGISTER, BIT)		REGISTER |= 1 << BIT
#define CLEAR(REGISTER, BIT)	REGISTER &= ~(1 << BIT)
#define TEST(REGISTER, BIT)		REGISTER & 1 << BIT
#define TOGGLE(REGISTER, BIT)	REGISTER ^= 1 << BIT

#define MODE_INPUT(BIT)		CLEAR(DDRB, BIT)
#define MODE_OUTPUT(BIT)	SET(DDRB, BIT)

#define D1 0
#define D2 1
#define D3 2
#define D4 4

int main()
{
    MODE_OUTPUT(D1);
    SET(PORTB, D1);

    return 0;
}