void init_spi(void)
{
    SPCR = (0 << SPIE)|(1 << SPE)|(0 << DORD)|(1 << MSTR)|(0 << CPOL)|(1 << CPHA)|(1 << SPR1)|(1 << SPR0);
    SPSR=0x00;
}

#define CLEARBIT(ADDRESS,BIT) (ADDRESS &= ~(1<<BIT))
#define SETBIT(ADDRESS,BIT) (ADDRESS |= (1<<BIT))

void spi_master_transmit(uint8_t data)
{
    transfer = false;
    SPDR = data;
    while(!(SPSR & (1<<SPIF)))
;
}

void change_one(uint8_t value)
{
    uint8_t tmp1 = 0;
    uint8_t tmp2 = 0;
    CLEARBIT(PORT_SYNC, PIN_SYNC);
    tmp1 += (value >> 4);
    tmp2 = (value << 4);
    spi_master_transmit(tmp1);
    spi_master_transmit(tmp2);
    SETBIT(PORT_SYNC, PIN_SYNC);
}

SETBIT(DDR_SCLK, PIN_SCLK);
SETBIT(PORT_SCLK, PIN_SCLK);

SETBIT(DDR_MOSI, PIN_MOSI);
SETBIT(PORT_MOSI, PIN_MOSI);

SETBIT(DDR_SYNC, PIN_SYNC);
SETBIT(PORT_SYNC, PIN_SYNC);