crc 16 implemetation

[roby]

hi,

this is the function to calcolate crc16 standard...

Thank all for help

roby

crc.au3

[ptrex]

@Roby

Good to see that you got it working !!

Maybe it's good to give an example on how to use this function for those who are not familiar with CRC calculations.

Regards

ptrex

[PsaltyDS]

hi,

this is the function to calcolate crc16 standard...

Thank all for help

roby

Cool. I did this demo to try it with some different values. Renamed it _StringCrc16() because it only works ASCII conversion of strings, not on binary values (it seems to me, anyway):

expandcollapse popup

Dim $avTest[5] = ["Test line 1.", "abcdefghijklmnopqrstuvwxyz01234567890", 0xFEDCBA98, "", StringToBinary("Binary test.")]
$sMsg = ""
For $n = 0 To UBound($avTest) - 1
    $sMsg &= $avTest[$n] & " CRC16 = " & _StringCrc16($avTest[$n]) & @CRLF
Next
MsgBox(64, "StringCrc16 Test", $sMsg)

; =======================================================
; Function      _StringCrc16
; Purpose:      Return the CRC16 checksum of the input value
; Author:       'roby' at http://www.autoitscript.com/forum
; =======================================================
Func _StringCrc16($value)
    Local $crc = 0x0000, $i = 0
    Local $table[256] = [ _
            0x0000, 0xC0C1, 0xC181, 0x0140, 0xC301, 0x03C0, 0x0280, 0xC241, _
            0xC601, 0x06C0, 0x0780, 0xC741, 0x0500, 0xC5C1, 0xC481, 0x0440, _
            0xCC01, 0x0CC0, 0x0D80, 0xCD41, 0x0F00, 0xCFC1, 0xCE81, 0x0E40, _
            0x0A00, 0xCAC1, 0xCB81, 0x0B40, 0xC901, 0x09C0, 0x0880, 0xC841, _
            0xD801, 0x18C0, 0x1980, 0xD941, 0x1B00, 0xDBC1, 0xDA81, 0x1A40, _
            0x1E00, 0xDEC1, 0xDF81, 0x1F40, 0xDD01, 0x1DC0, 0x1C80, 0xDC41, _
            0x1400, 0xD4C1, 0xD581, 0x1540, 0xD701, 0x17C0, 0x1680, 0xD641, _
            0xD201, 0x12C0, 0x1380, 0xD341, 0x1100, 0xD1C1, 0xD081, 0x1040, _
            0xF001, 0x30C0, 0x3180, 0xF141, 0x3300, 0xF3C1, 0xF281, 0x3240, _
            0x3600, 0xF6C1, 0xF781, 0x3740, 0xF501, 0x35C0, 0x3480, 0xF441, _
            0x3C00, 0xFCC1, 0xFD81, 0x3D40, 0xFF01, 0x3FC0, 0x3E80, 0xFE41, _
            0xFA01, 0x3AC0, 0x3B80, 0xFB41, 0x3900, 0xF9C1, 0xF881, 0x3840, _
            0x2800, 0xE8C1, 0xE981, 0x2940, 0xEB01, 0x2BC0, 0x2A80, 0xEA41, _
            0xEE01, 0x2EC0, 0x2F80, 0xEF41, 0x2D00, 0xEDC1, 0xEC81, 0x2C40, _
            0xE401, 0x24C0, 0x2580, 0xE541, 0x2700, 0xE7C1, 0xE681, 0x2640, _
            0x2200, 0xE2C1, 0xE381, 0x2340, 0xE101, 0x21C0, 0x2080, 0xE041, _
            0xA001, 0x60C0, 0x6180, 0xA141, 0x6300, 0xA3C1, 0xA281, 0x6240, _
            0x6600, 0xA6C1, 0xA781, 0x6740, 0xA501, 0x65C0, 0x6480, 0xA441, _
            0x6C00, 0xACC1, 0xAD81, 0x6D40, 0xAF01, 0x6FC0, 0x6E80, 0xAE41, _
            0xAA01, 0x6AC0, 0x6B80, 0xAB41, 0x6900, 0xA9C1, 0xA881, 0x6840, _
            0x7800, 0xB8C1, 0xB981, 0x7940, 0xBB01, 0x7BC0, 0x7A80, 0xBA41, _
            0xBE01, 0x7EC0, 0x7F80, 0xBF41, 0x7D00, 0xBDC1, 0xBC81, 0x7C40, _
            0xB401, 0x74C0, 0x7580, 0xB541, 0x7700, 0xB7C1, 0xB681, 0x7640, _
            0x7200, 0xB2C1, 0xB381, 0x7340, 0xB101, 0x71C0, 0x7080, 0xB041, _
            0x5000, 0x90C1, 0x9181, 0x5140, 0x9301, 0x53C0, 0x5280, 0x9241, _
            0x9601, 0x56C0, 0x5780, 0x9741, 0x5500, 0x95C1, 0x9481, 0x5440, _
            0x9C01, 0x5CC0, 0x5D80, 0x9D41, 0x5F00, 0x9FC1, 0x9E81, 0x5E40, _
            0x5A00, 0x9AC1, 0x9B81, 0x5B40, 0x9901, 0x59C0, 0x5880, 0x9841, _
            0x8801, 0x48C0, 0x4980, 0x8941, 0x4B00, 0x8BC1, 0x8A81, 0x4A40, _
            0x4E00, 0x8EC1, 0x8F81, 0x4F40, 0x8D01, 0x4DC0, 0x4C80, 0x8C41, _
            0x4400, 0x84C1, 0x8581, 0x4540, 0x8701, 0x47C0, 0x4680, 0x8641, _
            0x8201, 0x42C0, 0x4380, 0x8341, 0x4100, 0x81C1, 0x8081, 0x4040 ]
    ConsoleWrite("Debug: $value = " & $value & "  Len = " & StringLen($value) & @LF)
    For $i = 1 To StringLen($value)
        $crc = BitXOR(BitShift($crc, 8), $table[BitAND(BitXOR($crc, Asc(StringMid($value, $i, 1))), 0xFF) ])
    Next
    Return Hex($crc, 4)
EndFunc   ;==>_StringCrc16

P.S. Also inserted the ConsoleWrite() to see what assumptions were being made about the input $value.

Edited October 18, 2007 by PsaltyDS

[bilibili2011]

Hi, nobody can make an hex version ?

thanks

[Melba23]

bilibili2011,

Welcome to the AutoIt forums.

But did you notice that the post above yours in this thread dates from over 7 years ago and that the OP has not been online for over 2.5 years?

Please do not necro-post like this again - just open a new thread and link to the old one if it is absolutely necessary for understanding the problem. We ask you to do this for two main reasons:

 

- 1. The language advances and the functionality might well be included in core or UDF code by now

- 2. The changes in language syntax mean that it is likely that code from more than a couple of years ago may well not run under the current release interpreter without significant modification.

M23