$crc=255; 
$data[0]=readByte();
do
  { $_=sprintf("%08b",readByte());                                                # BYTE1
    $byte2='';  
    while (m/(.)/g)
    { if ($1 == 0) { $byte2.='00000000';}
      else         { $byte2.=sprintf("%08b",readByte());}                         # positions bytes
    } 
    $data[pos($byte2)]=readByte() while ($byte2=~m/(1)/g);                        # put data value into @data on the correct position 
    readByte(); if ($crc>0) {print "ERROR:  CRC (POS:".pos($f).')'; exit; }       # crc check
    $crc=255;
    # ---- USE DATA => DELETED --------
    
    $data[0]=readByte();
  } while ($data[0]<255);
}

sub readByte
{ unless ($f=~m/(.)/gs) {print "Last data structure not complete !"; exit;}
  my $x=ord($1);
  $crc^=$x;                                                 # CRC
  for my $r(1..8)
  { if (($crc&1)>0) {$crc=($crc>>1)^0x8c;}
    else            {$crc=$crc>>1;}  
  }
  return ($x); 
}