void scrollMessage( char *str )
{
    char msg[] = "123456789";
    const uint8_t width = 4;
    char vram[width];
    int8_t pos = 0;
    pos -= width;

    while (1)
    {
        for ( int8_t ramPos = 0 ; ramPos < width - 1; ramPos++ )
        {
            if ( (pos + ramPos) < 0 )
            {
                vram[ramPos] = 11; // Leerzeichen
            }
            else if ( (pos + ramPos) > strlen(msg) - 1 )
            {
                vram[ramPos] = 11; // Leerzeichen
            }
            else
            {
                vram[ramPos] = msg[ pos + ramPos ] - '0';
            }

            if( pos == strlen(msg) + width )
            {
                pos = -width;
            }
            else
            {
                pos += 1;
            }
        }

        for ( uint8_t i = 0 ; i < 4 ; i++ )
        {
            disp.dig[i] = vram[i];
            _delay_ms(250);
        }
    }
}