Código:
Private Declare Function WideCharToMultiByte Lib "kernel32" ( _
ByVal CodePage As Long, _
ByVal dwFlags As Long, _
ByVal lpWideCharStr As Long, _
ByVal cchWideChar As Long, _
ByVal lpMultiByteStr As Long, _
ByVal cbMultiByte As Long, _
ByVal lpDefaultChar As Long, _
ByVal lpUsedDefaultChar As Long) As Long
Dim CRC8_Table As Variant
' CodePage constant for UTF-8
Private Const CP_UTF8 = 65001
''' Return byte array with VBA "Unicode" string encoded in UTF-8
Function Utf8BytesFromString(strInput As String) As Variant
Dim nBytes As Long
' Catch empty or null input string
Utf8BytesFromString = vbNullString
If Len(strInput) < 1 Then Exit Function
' Get length in bytes *including* terminating null
nBytes = WideCharToMultiByte(CP_UTF8, 0&, ByVal StrPtr(strInput), -1, 0&, 0&, 0&, 0&)
' We don't want the terminating null in our byte array, so ask for `nBytes-1` bytes
Dim abBuffer() As Byte
ReDim abBuffer(nBytes - 2) ' NB ReDim with one less byte than you need
nBytes = WideCharToMultiByte(CP_UTF8, 0&, ByVal StrPtr(strInput), -1, ByVal VarPtr(abBuffer(0)), nBytes - 1, 0&, 0&)
Utf8BytesFromString = abBuffer
End Function
Public Function crc8(buffer As String, Polynom, Initial As Variant) As Variant
CRC8_Table = Array(&H0, &H7, &HE, &H9, &H1C, &H1B, &H12, &H15, _
&H38, &H3F, &H36, &H31, &H24, &H23, &H2A, &H2D, &H70, &H77, &H7E, &H79, &H6C, &H6B, &H62, &H65, _
&H48, &H4F, &H46, &H41, &H54, &H53, &H5A, &H5D, &HE0, &HE7, &HEE, &HE9, &HFC, &HFB, &HF2, &HF5, _
&HD8, &HDF, &HD6, &HD1, &HC4, &HC3, &HCA, &HCD, &H90, &H97, &H9E, &H99, &H8C, &H8B, &H82, &H85, _
&HA8, &HAF, &HA6, &HA1, &HB4, &HB3, &HBA, &HBD, &HC7, &HC0, &HC9, &HCE, &HDB, &HDC, &HD5, &HD2, _
&HFF, &HF8, &HF1, &HF6, &HE3, &HE4, &HED, &HEA, &HB7, &HB0, &HB9, &HBE, &HAB, &HAC, &HA5, &HA2, _
&H8F, &H88, &H81, &H86, &H93, &H94, &H9D, &H9A, &H27, &H20, &H29, &H2E, &H3B, &H3C, &H35, &H32, _
&H1F, &H18, &H11, &H16, &H3, &H4, &HD, &HA, &H57, &H50, &H59, &H5E, &H4B, &H4C, &H45, &H42, _
&H6F, &H68, &H61, &H66, &H73, &H74, &H7D, &H7A, &H89, &H8E, &H87, &H80, &H95, &H92, &H9B, &H9C, _
&HB1, &HB6, &HBF, &HB8, &HAD, &HAA, &HA3, &HA4, &HF9, &HFE, &HF7, &HF0, &HE5, &HE2, &HEB, &HEC, _
&HC1, &HC6, &HCF, &HC8, &HDD, &HDA, &HD3, &HD4, &H69, &H6E, &H67, &H60, &H75, &H72, &H7B, &H7C, _
&H51, &H56, &H5F, &H58, &H4D, &H4A, &H43, &H44, &H19, &H1E, &H17, &H10, &H5, &H2, &HB, &HC, _
&H21, &H26, &H2F, &H28, &H3D, &H3A, &H33, &H34, &H4E, &H49, &H40, &H47, &H52, &H55, &H5C, &H5B, _
&H76, &H71, &H78, &H7F, &H6A, &H6D, &H64, &H63, &H3E, &H39, &H30, &H37, &H22, &H25, &H2C, &H2B, _
&H6, &H1, &H8, &HF, &H1A, &H1D, &H14, &H13, &HAE, &HA9, &HA0, &HA7, &HB2, &HB5, &HBC, &HBB, _
&H96, &H91, &H98, &H9F, &H8A, &H8D, &H84, &H83, &HDE, &HD9, &HD0, &HD7, &HC2, &HC5, &HCC, &HCB, _
&HE6, &HE1, &HE8, &HEF, &HFA, &HFD, &HF4, &HF3)
Dim data As Variant
data = Utf8BytesFromString(buffer)
Dim alen, i As Integer
Dim crc As Byte
'data = Buffer ':= TEncoding.UTF8.GetBytes(Cadena);
alen = UBound(data)
crc = 0
For i = 0 To alen
crc = CRC8_Table((crc Xor data(i)) And &HFF)
Next
crc8 = crc And &HFF
End Function