unsigned char ChanByte(unsigned char DatBye)
{
    unsigned char i, j = 0, k = 0, HightBit, LowBit;

        HightBit = DatBye & 0xf0;
        LowBit   = DatBye & 0x0f;

        for(i = 0; i < 4; i ++)
        {
            j = (HightBit >> (i + 4)) & 0x01;
                k |= j << (7 - i);
        }

        k |= LowBit;

        return k;
}