'******************************************************************************
'API constants, listed alphabetically
'******************************************************************************

'from setupapi.h
Public Const DIGCF_PRESENT = &H2
Public Const DIGCF_DEVICEINTERFACE = &H10

Public Const FORMAT_MESSAGE_FROM_SYSTEM = &H1000
Public Const GENERIC_READ = &H80000000
Public Const GENERIC_WRITE = &H40000000
Public Const FILE_SHARE_READ = &H1
Public Const FILE_SHARE_WRITE = &H2

'Typedef enum defines a set of integer constants for HidP_Report_Type
'Remember to declare these as integers (16 bits)
Public Const HidP_Input = 0
Public Const HidP_Output = 1
Public Const HidP_Feature = 2

Public Const OPEN_EXISTING = 3

'******************************************************************************
'User-defined types for API calls, listed alphabetically
'******************************************************************************

Public Type GUID
    Data1 As Long
    Data2 As Integer
    Data3 As Integer
    Data4(7) As Byte
End Type

Public Type HIDD_ATTRIBUTES
    Size As Long
    VendorID As Integer
    ProductID As Integer
    VersionNumber As Integer
End Type

'Windows 98 DDK documentation is incomplete.
'Use the structure defined in hidpi.h
Public Type HIDP_CAPS
    Usage As Integer
    UsagePage As Integer
    InputReportByteLength As Integer
    OutputReportByteLength As Integer
    FeatureReportByteLength As Integer
    Reserved(16) As Integer
    NumberLinkCollectionNodes As Integer
    NumberInputButtonCaps As Integer
    NumberInputValueCaps As Integer
    NumberInputDataIndices As Integer
    NumberOutputButtonCaps As Integer
    NumberOutputValueCaps As Integer
    NumberOutputDataIndices As Integer
    NumberFeatureButtonCaps As Integer
    NumberFeatureValueCaps As Integer
    NumberFeatureDataIndices As Integer
End Type

'If IsRange is false, UsageMin is the Usage and UsageMax is unused.
'If IsStringRange is false, StringMin is the string index and StringMax is unused.
'If IsDesignatorRange is false, DesignatorMin is the designator index and DesignatorMax is unused.
Public Type HidP_Value_Caps
    UsagePage As Integer
    ReportID As Byte
    IsAlias As Long
    BitField As Integer
    LinkCollection As Integer
    LinkUsage As Integer
    LinkUsagePage As Integer
    IsRange As Long
    IsStringRange As Long
    IsDesignatorRange As Long
    IsAbsolute As Long
    HasNull As Long
    Reserved As Byte
    BitSize As Integer
    ReportCount As Integer
    Reserved2 As Integer
    Reserved3 As Integer
    Reserved4 As Integer
    Reserved5 As Integer
    Reserved6 As Integer
    LogicalMin As Long
    LogicalMax As Long
    PhysicalMin As Long
    PhysicalMax As Long
    UsageMin As Integer
    UsageMax As Integer
    StringMin As Integer
    StringMax As Integer
    DesignatorMin As Integer
    DesignatorMax As Integer
    DataIndexMin As Integer
    DataIndexMax As Integer
End Type

Public Type SP_DEVICE_INTERFACE_DATA
   cbSize As Long
   InterfaceClassGuid As GUID
   Flags As Long
   Reserved As Long
End Type

Public Type SP_DEVICE_INTERFACE_DETAIL_DATA
    cbSize As Long
    DevicePath As Byte
End Type

Public Type SP_DEVINFO_DATA
    cbSize As Long
    ClassGuid As GUID
    DevInst As Long
    Reserved As Long
End Type

'******************************************************************************
'API functions, listed alphabetically
'******************************************************************************

Public Declare Function CloseHandle _
    Lib "kernel32" _
    (ByVal hObject As Long) _
As Long

Public Declare Function CreateFile _
    Lib "kernel32" _
    Alias "CreateFileA" _
    (ByVal lpFileName As String, _
    ByVal dwDesiredAccess As Long, _
    ByVal dwShareMode As Long, _
    ByRef lpSecurityAttributes As Long, _
    ByVal dwCreationDisposition As Long, _
    ByVal dwFlagsAndAttributes As Long, _
    ByVal hTemplateFile As Long) _
As Long

Public Declare Function FormatMessage _
    Lib "kernel32" _
    Alias "FormatMessageA" _
    (ByVal dwFlags As Long, _
    ByRef lpSource As Any, _
    ByVal dwMessageId As Long, _
    ByVal dwLanguageZId As Long, _
    ByVal lpBuffer As String, _
    ByVal nSize As Long, _
    ByVal Arguments As Long) _
As Long

Public Declare Function HidD_FreePreparsedData _
    Lib "hid.dll" _
    (ByRef PreparsedData As Long) _
As Long

Public Declare Function HidD_GetAttributes _
    Lib "hid.dll" _
    (ByVal HidDeviceObject As Long, _
    ByRef Attributes As HIDD_ATTRIBUTES) _
As Long

'Declared as a function for consistency,
'but returns nothing. (Ignore the returned value.)
Public Declare Function HidD_GetHidGuid _
    Lib "hid.dll" _
    (ByRef HidGuid As GUID) _
As Long

Public Declare Function HidD_GetPreparsedData _
    Lib "hid.dll" _
    (ByVal HidDeviceObject As Long, _
    ByRef PreparsedData As Long) _
As Long

Public Declare Function HidP_GetCaps _
    Lib "hid.dll" _
    (ByVal PreparsedData As Long, _
    ByRef Capabilities As HIDP_CAPS) _
As Long

Public Declare Function HidP_GetValueCaps _
    Lib "hid.dll" _
    (ByVal ReportType As Integer, _
    ByRef ValueCaps As Byte, _
    ByRef ValueCapsLength As Integer, _
    ByVal PreparsedData As Long) _
As Long
       
Public Declare Function lstrcpy _
    Lib "kernel32" _
    Alias "lstrcpyA" _
    (ByVal dest As String, _
    ByVal source As Long) _
As String

Public Declare Function lstrlen _
    Lib "kernel32" _
    Alias "lstrlenA" _
    (ByVal source As Long) _
As Long

Public Declare Function ReadFile _
    Lib "kernel32" _
    (ByVal hFile As Long, _
    ByRef lpBuffer As Byte, _
    ByVal nNumberOfBytesToRead As Long, _
    ByRef lpNumberOfBytesRead As Long, _
    ByVal lpOverlapped As Long) _
As Long

Public Declare Function RtlMoveMemory _
    Lib "kernel32" _
    (dest As Any, _
    src As Any, _
    ByVal Count As Long) _
As Long

Public Declare Function SetupDiCreateDeviceInfoList _
    Lib "setupapi.dll" _
    (ByRef ClassGuid As GUID, _
    ByVal hwndParent As Long) _
As Long

Public Declare Function SetupDiDestroyDeviceInfoList _
    Lib "setupapi.dll" _
    (ByVal DeviceInfoSet As Long) _
As Long

Public Declare Function SetupDiEnumDeviceInterfaces _
    Lib "setupapi.dll" _
    (ByVal DeviceInfoSet As Long, _
    ByVal DeviceInfoData As Long, _
    ByRef InterfaceClassGuid As GUID, _
    ByVal MemberIndex As Long, _
    ByRef DeviceInterfaceData As SP_DEVICE_INTERFACE_DATA) _
As Long

Public Declare Function SetupDiGetClassDevs _
    Lib "setupapi.dll" _
    Alias "SetupDiGetClassDevsA" _
    (ByRef ClassGuid As GUID, _
    ByVal Enumerator As String, _
    ByVal hwndParent As Long, _
    ByVal Flags As Long) _
As Long

Public Declare Function SetupDiGetDeviceInterfaceDetail _
   Lib "setupapi.dll" _
   Alias "SetupDiGetDeviceInterfaceDetailA" _
   (ByVal DeviceInfoSet As Long, _
   ByRef DeviceInterfaceData As SP_DEVICE_INTERFACE_DATA, _
   ByVal DeviceInterfaceDetailData As Long, _
   ByVal DeviceInterfaceDetailDataSize As Long, _
   ByRef RequiredSize As Long, _
   ByVal DeviceInfoData As Long) _
As Long
   
Public Declare Function WriteFile _
    Lib "kernel32" _
    (ByVal hFile As Long, _
    ByRef lpBuffer As Byte, _
    ByVal nNumberOfBytesToWrite As Long, _
    ByRef lpNumberOfBytesWritten As Long, _
    ByVal lpOverlapped As Long) _
As Long

Private Sub cmdOnce_Click()
Call ReadAndWriteToDevice
End Sub
Private Sub DisplayResultOfAPICall(FunctionName As String)

'Display the results of an API call.

Dim ErrorString As String

lstResults.AddItem ""
ErrorString = GetErrorString(Err.LastDllError)
lstResults.AddItem FunctionName
lstResults.AddItem "  Result = " & ErrorString

'Scroll to the bottom of the list box.
lstResults.ListIndex = lstResults.ListCount - 1

End Sub

Private Sub Form_Load()
frmMain.Show
tmrDelay.Enabled = False
Call Startup
End Sub

Private Sub Form_Unload(Cancel As Integer)
Call Shutdown
End Sub

Private Sub GetDeviceCapabilities()

'******************************************************************************
'HidD_GetPreparsedData
'Returns: a pointer to a buffer containing information about the device's capabilities.
'Requires: A handle returned by CreateFile.
'There's no need to access the buffer directly,
'but HidP_GetCaps and other API functions require a pointer to the buffer.
'******************************************************************************

Dim ppData(29) As Byte
Dim ppDataString As Variant

'Preparsed Data is a pointer to a routine-allocated buffer.
Result = HidD_GetPreparsedData _
    (HidDevice, _
    PreparsedData)
Call DisplayResultOfAPICall("HidD_GetPreparsedData")

'Copy the data at PreparsedData into a byte array.

Result = RtlMoveMemory _
    (ppData(0), _
    PreparsedData, _
    30)
Call DisplayResultOfAPICall("RtlMoveMemory")

ppDataString = ppData()
'Convert the data to Unicode.
ppDataString = StrConv(ppDataString, vbUnicode)

'******************************************************************************
'HidP_GetCaps
'Find out the device's capabilities.
'For standard devices such as joysticks, you can find out the specific
'capabilities of the device.
'For a custom device, the software will probably know what the device is capable of,
'so this call only verifies the information.
'Requires: The pointer to a buffer containing the information.
'The pointer is returned by HidD_GetPreparsedData.
'Returns: a Capabilites structure containing the information.
'******************************************************************************
Result = HidP_GetCaps _
    (PreparsedData, _
    Capabilities)

Call DisplayResultOfAPICall("HidP_GetCaps")
lstResults.AddItem "  Last error: " & ErrorString
lstResults.AddItem "  Usage: " & Hex$(Capabilities.Usage)
lstResults.AddItem "  Usage Page: " & Hex$(Capabilities.UsagePage)
lstResults.AddItem "  Input Report Byte Length: " & Capabilities.InputReportByteLength
lstResults.AddItem "  Output Report Byte Length: " & Capabilities.OutputReportByteLength
lstResults.AddItem "  Feature Report Byte Length: " & Capabilities.FeatureReportByteLength
lstResults.AddItem "  Number of Link Collection Nodes: " & Capabilities.NumberLinkCollectionNodes
lstResults.AddItem "  Number of Input Button Caps: " & Capabilities.NumberInputButtonCaps
lstResults.AddItem "  Number of Input Value Caps: " & Capabilities.NumberInputValueCaps
lstResults.AddItem "  Number of Input Data Indices: " & Capabilities.NumberInputDataIndices
lstResults.AddItem "  Number of Output Button Caps: " & Capabilities.NumberOutputButtonCaps
lstResults.AddItem "  Number of Output Value Caps: " & Capabilities.NumberOutputValueCaps
lstResults.AddItem "  Number of Output Data Indices: " & Capabilities.NumberOutputDataIndices
lstResults.AddItem "  Number of Feature Button Caps: " & Capabilities.NumberFeatureButtonCaps
lstResults.AddItem "  Number of Feature Value Caps: " & Capabilities.NumberFeatureValueCaps
lstResults.AddItem "  Number of Feature Data Indices: " & Capabilities.NumberFeatureDataIndices

'******************************************************************************
'HidP_GetValueCaps
'Returns a buffer containing an array of HidP_ValueCaps structures.
'Each structure defines the capabilities of one value.
'This application doesn't use this data.
'******************************************************************************

'This is a guess. The byte array holds the structures.
Dim ValueCaps(1023) As Byte

Result = HidP_GetValueCaps _
    (HidP_Input, _
    ValueCaps(0), _
    Capabilities.NumberInputValueCaps, _
    PreparsedData)
   
Call DisplayResultOfAPICall("HidP_GetValueCaps")

'lstResults.AddItem "ValueCaps= " & GetDataString((VarPtr(ValueCaps(0))), 180)
'To use this data, copy the byte array into an array of structures.

End Sub

Private Sub InitializeDisplay()
Dim Count As Integer
Dim ByteValue As String
'Create a dropdown list box for each byte to send.
For Count = 0 To 255
    If Len(Hex$(Count)) < 2 Then
        ByteValue = "0" & Hex$(Count)
    Else
        ByteValue = Hex$(Count)
    End If
    frmMain.cboByte0.AddItem ByteValue, Count
Next Count
For Count = 0 To 255
    If Len(Hex$(Count)) < 2 Then
        ByteValue = "0" & Hex$(Count)
    Else
        ByteValue = Hex$(Count)
    End If
    frmMain.cboByte1.AddItem ByteValue, Count
Next Count
'Select a default item for each box
frmMain.cboByte0.ListIndex = 0
frmMain.cboByte1.ListIndex = 128
End Sub

Private Sub ReadAndWriteToDevice()
'Sends two bytes to the device and reads two bytes back.

Dim DeviceDetected As Boolean

'Report Header
lstResults.AddItem "HID Test Report"
lstResults.AddItem Format(Now, "general date")

'Some data to send
'(if not using the combo boxes):
'OutputReportData(0) = &H12
'OutputReportData(1) = &H34
'OutputReportData(2) = &HF0
'OutputReportData(3) = &HF1
'OutputReportData(4) = &HF2
'OutputReportData(5) = &HF3
'OutputReportData(6) = &HF4
'OutputReportData(7) = &HF5

'Get the bytes to send from the combo boxes.
'Increment the values if the autoincrement check box is selected.
If chkAutoincrement.Value = 1 Then
    If cboByte0.ListIndex < 255 Then
        cboByte0.ListIndex = cboByte0.ListIndex + 1
    Else
        cboByte0.ListIndex = 0
    End If
    If cboByte1.ListIndex < 255 Then
        cboByte1.ListIndex = cboByte1.ListIndex + 1
    Else
        cboByte1.ListIndex = 0
    End If
End If

OutputReportData(0) = cboByte0.ListIndex
OutputReportData(1) = cboByte1.ListIndex

'Find the device
DeviceDetected = FindTheHid
If DeviceDetected = True Then
    'Learn the capabilities of the device
    Call GetDeviceCapabilities
    'Write a report to the device
    Call WriteReport
   
    'The firmware adds 1 to each received byte and sends the bytes back
    'to the host.
    'Add a delay to allow the host time to poll for the returned data.
    Timeout = False
    tmrDelay.Interval = 100
    tmrDelay.Enabled = True
    Do
        DoEvents
    Loop Until Timeout = True
    'Read a report from the device.
    Call ReadReport
Else
End If

'Scroll to the bottom of the list box.
lstResults.ListIndex = lstResults.ListCount - 1

End Sub

Private Sub ReadReport()

'Read data from the device.

Dim Count
Dim NumberOfBytesRead As Long
'Allocate a buffer for the report.
'Byte 0 is the report ID.
Dim ReadBuffer() As Byte
Dim UBoundReadBuffer As Integer

'******************************************************************************
'ReadFile
'Returns: the report in ReadBuffer.
'Requires: a device handle returned by CreateFile,
'the Input report length in bytes returned by HidP_GetCaps.
'******************************************************************************

'ReadFile is a blocking call. The application will hang until the device
'sends the requested amount of data. To prevent hanging, be sure that
'the device always has data to send.

Dim ByteValue As String
'The ReadBuffer array begins at 0, so subtract 1 from the number of bytes.
ReDim ReadBuffer(Capabilities.InputReportByteLength - 1)
   
'Pass the address of the first byte of the read buffer.
Result = ReadFile _
    (HidDevice, _
    ReadBuffer(0), _
    CLng(Capabilities.InputReportByteLength), _
    NumberOfBytesRead, _
    0)
Call DisplayResultOfAPICall("ReadFile")

lstResults.AddItem " Report ID: " & ReadBuffer(0)
lstResults.AddItem " Report Data:"

txtBytesReceived.Text = ""
For Count = 1 To UBound(ReadBuffer)
    'Add a leading 0 to values 0 - Fh.
    If Len(Hex$(ReadBuffer(Count))) < 2 Then
        ByteValue = "0" & Hex$(ReadBuffer(Count))
    Else
        ByteValue = Hex$(ReadBuffer(Count))
    End If
    lstResults.AddItem " " & ByteValue
    'Display the received bytes in the text box.
    txtBytesReceived.SelStart = Len(txtBytesReceived.Text)
    txtBytesReceived.SelText = ByteValue & vbCrLf
   
Next Count
End Sub

Private Sub Shutdown()
'Includes actions that must execute when the program ends.

'Close the open handle to the device.
Result = CloseHandle _
    (HidDevice)
Call DisplayResultOfAPICall("CloseHandle (HidDevice)")

'Free memory used by SetupDiGetClassDevs
'Nonzero = success
Result = SetupDiDestroyDeviceInfoList _
    (DeviceInfoSet)
Call DisplayResultOfAPICall("DestroyDeviceInfoList")

Result = HidD_FreePreparsedData _
    (PreparsedData)
Call DisplayResultOfAPICall("HidD_FreePreparsedData")

End Sub

Private Sub Startup()
Call InitializeDisplay
tmrContinuousDataCollect.Enabled = False
tmrContinuousDataCollect.Interval = 1000
End Sub

Private Sub tmrContinuousDataCollect_Timer()
Call ReadAndWriteToDevice

End Sub

Private Sub tmrDelay_Timer()
Timeout = True
tmrDelay.Enabled = False
End Sub

Private Sub WriteReport()
'Send data to the device.

Dim Count As Integer
Dim NumberOfBytesRead As Long
Dim NumberOfBytesToSend As Long
Dim NumberOfBytesWritten As Long
Dim ReadBuffer() As Byte
Dim SendBuffer() As Byte

'The SendBuffer array begins at 0, so subtract 1 from the number of bytes.
ReDim SendBuffer(Capabilities.OutputReportByteLength - 1)

'******************************************************************************
'WriteFile
'Sends a report to the device.
'Returns: success or failure.
'Requires: the handle returned by CreateFile and
'The output report byte length returned by HidP_GetCaps
'******************************************************************************

'The first byte is the Report ID
SendBuffer(0) = 0

'The next bytes are data
For Count = 1 To Capabilities.OutputReportByteLength - 1
    SendBuffer(Count) = OutputReportData(Count - 1)
Next Count

NumberOfBytesWritten = 0

Result = WriteFile _
    (HidDevice, _
    SendBuffer(0), _
    CLng(Capabilities.OutputReportByteLength), _
    NumberOfBytesWritten, _
    0)
Call DisplayResultOfAPICall("WriteFile")

lstResults.AddItem " OutputReportByteLength = " & Capabilities.OutputReportByteLength
lstResults.AddItem " NumberOfBytesWritten = " & NumberOfBytesWritten
lstResults.AddItem " Report ID: " & SendBuffer(0)
lstResults.AddItem " Report Data:"

For Count = 1 To UBound(SendBuffer)
    lstResults.AddItem " " & Hex$(SendBuffer(Count))
Next Count

End Sub

Option Explicit


Dim Capabilities As HIDP_CAPS
Dim DataString As String
Dim DetailData As Long
Dim DetailDataBuffer() As Byte
Dim DeviceAttributes As HIDD_ATTRIBUTES
Dim DevicePathName As String
Dim DeviceInfoSet As Long
Dim ErrorString As String
Dim HidDevice As Long
Dim LastDevice As Boolean
Dim MyDeviceDetected As Boolean
Dim MyDeviceInfoData As SP_DEVINFO_DATA
Dim MyDeviceInterfaceDetailData As SP_DEVICE_INTERFACE_DETAIL_DATA
Dim MyDeviceInterfaceData As SP_DEVICE_INTERFACE_DATA
Dim Needed As Long
Dim OutputReportData(7) As Byte
Dim PreparsedData As Long
Dim Result As Long
Dim Timeout As Boolean

'Set these to match the values in the device's firmware and INF file.
Const MyVendorID = &H925
Const MyProductID = &H1234

Function FindTheHid() As Boolean
'Makes a series of API calls to locate the desired HID-class device.
'Returns True if the device is detected, False if not detected.

Dim Count As Integer
Dim GUIDString As String
Dim HidGuid As GUID
Dim MemberIndex As Long

LastDevice = False
MyDeviceDetected = False

'******************************************************************************
'HidD_GetHidGuid
'Get the GUID for all system HIDs.
'Returns: the GUID in HidGuid.
'The routine doesn't return a value in Result
'but the routine is declared as a function for consistency with the other API calls.
'******************************************************************************

Result = HidD_GetHidGuid(HidGuid)
Call DisplayResultOfAPICall("GetHidGuid")

'Display the GUID.
GUIDString = _
    Hex$(HidGuid.Data1) & "-" & _
    Hex$(HidGuid.Data2) & "-" & _
    Hex$(HidGuid.Data3) & "-"

For Count = 0 To 7
    'Ensure that each of the 8 bytes in the GUID displays two characters.
    If HidGuid.Data4(Count) >= &H10 Then
        GUIDString = GUIDString & Hex$(HidGuid.Data4(Count)) & " "
    Else
        GUIDString = GUIDString & "0" & Hex$(HidGuid.Data4(Count)) & " "
    End If
Next Count

lstResults.AddItem "  GUID for system HIDs: " & GUIDString

'******************************************************************************
'SetupDiGetClassDevs
'Returns: a handle to a device information set for all installed devices.
'Requires: the HidGuid returned in GetHidGuid.
'******************************************************************************

DeviceInfoSet = SetupDiGetClassDevs _
    (HidGuid, _
    vbNullString, _
    0, _
    (DIGCF_PRESENT Or DIGCF_DEVICEINTERFACE))
   
Call DisplayResultOfAPICall("SetupDiClassDevs")
DataString = GetDataString(DeviceInfoSet, 32)

'******************************************************************************
'SetupDiEnumDeviceInterfaces
'On return, MyDeviceInterfaceData contains the handle to a
'SP_DEVICE_INTERFACE_DATA structure for a detected device.
'Requires:
'the DeviceInfoSet returned in SetupDiGetClassDevs.
'the HidGuid returned in GetHidGuid.
'An index to specify a device.
'******************************************************************************

'Begin with 0 and increment until no more devices are detected.
MemberIndex = 0

Do
    'The cbSize element of the MyDeviceInterfaceData structure must be set to
    'the structure's size in bytes. The size is 28 bytes.
    MyDeviceInterfaceData.cbSize = LenB(MyDeviceInterfaceData)
    Result = SetupDiEnumDeviceInterfaces _
        (DeviceInfoSet, _
        0, _
        HidGuid, _
        MemberIndex, _
        MyDeviceInterfaceData)
   
    Call DisplayResultOfAPICall("SetupDiEnumDeviceInterfaces")
    If Result = 0 Then LastDevice = True
   
    'If a device exists, display the information returned.
    If Result <> 0 Then
        lstResults.AddItem "  DeviceInfoSet for device #" & CStr(MemberIndex) & ": "
        lstResults.AddItem "  cbSize = " & CStr(MyDeviceInterfaceData.cbSize)
        lstResults.AddItem _
            "  InterfaceClassGuid.Data1 = " & Hex$(MyDeviceInterfaceData.InterfaceClassGuid.Data1)
        lstResults.AddItem _
            "  InterfaceClassGuid.Data2 = " & Hex$(MyDeviceInterfaceData.InterfaceClassGuid.Data2)
        lstResults.AddItem _
            "  InterfaceClassGuid.Data3 = " & Hex$(MyDeviceInterfaceData.InterfaceClassGuid.Data3)
        lstResults.AddItem _
            "  Flags = " & Hex$(MyDeviceInterfaceData.Flags)
   
       
        '******************************************************************************
        'SetupDiGetDeviceInterfaceDetail
        'Returns: an SP_DEVICE_INTERFACE_DETAIL_DATA structure
        'containing information about a device.
        'To retrieve the information, call this function twice.
        'The first time returns the size of the structure in Needed.
        'The second time returns a pointer to the data in DeviceInfoSet.
        'Requires:
        'A DeviceInfoSet returned by SetupDiGetClassDevs and
        'an SP_DEVICE_INTERFACE_DATA structure returned by SetupDiEnumDeviceInterfaces.
        '*******************************************************************************
       
        MyDeviceInfoData.cbSize = Len(MyDeviceInfoData)
        Result = SetupDiGetDeviceInterfaceDetail _
           (DeviceInfoSet, _
           MyDeviceInterfaceData, _
           0, _
           0, _
           Needed, _
           0)
       
        DetailData = Needed
           
        Call DisplayResultOfAPICall("SetupDiGetDeviceInterfaceDetail")
        lstResults.AddItem "  (OK to say too small)"
        lstResults.AddItem "  Required buffer size for the data: " & Needed
       
        'Store the structure's size.
        MyDeviceInterfaceDetailData.cbSize = _
            Len(MyDeviceInterfaceDetailData)
       
        'Use a byte array to allocate memory for
        'the MyDeviceInterfaceDetailData structure
        ReDim DetailDataBuffer(Needed)
        'Store cbSize in the first four bytes of the array.
        Call RtlMoveMemory _
            (DetailDataBuffer(0), _
            MyDeviceInterfaceDetailData, _
            4)
       
        'Call SetupDiGetDeviceInterfaceDetail again.
        'This time, pass the address of the first element of DetailDataBuffer
        'and the returned required buffer size in DetailData.
        Result = SetupDiGetDeviceInterfaceDetail _
           (DeviceInfoSet, _
           MyDeviceInterfaceData, _
           VarPtr(DetailDataBuffer(0)), _
           DetailData, _
           Needed, _
           0)
       
        Call DisplayResultOfAPICall(" Result of second call: ")
        lstResults.AddItem "  MyDeviceInterfaceDetailData.cbSize: " & _
            CStr(MyDeviceInterfaceDetailData.cbSize)
       
        'Convert the byte array to a string.
        DevicePathName = CStr(DetailDataBuffer())
        'Convert to Unicode.
        DevicePathName = StrConv(DevicePathName, vbUnicode)
        'Strip cbSize (4 bytes) from the beginning.
        DevicePathName = Right$(DevicePathName, Len(DevicePathName) - 4)
        lstResults.AddItem "  Device pathname: "
        lstResults.AddItem "    " & DevicePathName
               
        '******************************************************************************
        'CreateFile
        'Returns: a handle that enables reading and writing to the device.
        'Requires:
        'The DevicePathName returned by SetupDiGetDeviceInterfaceDetail.
        '******************************************************************************
   
        HidDevice = CreateFile _
            (DevicePathName, _
            GENERIC_READ Or GENERIC_WRITE, _
            (FILE_SHARE_READ Or FILE_SHARE_WRITE), _
            0, _
            OPEN_EXISTING, _
            0, _
            0)
           
        Call DisplayResultOfAPICall("CreateFile")
        lstResults.AddItem "  Returned handle: " & Hex$(HidDevice) & "h"
       
        'Now we can find out if it's the device we're looking for.
       
        '******************************************************************************
        'HidD_GetAttributes
        'Requests information from the device.
        'Requires: The handle returned by CreateFile.
        'Returns: an HIDD_ATTRIBUTES structure containing
        'the Vendor ID, Product ID, and Product Version Number.
        'Use this information to determine if the detected device
        'is the one we're looking for.
        '******************************************************************************
       
        'Set the Size property to the number of bytes in the structure.
        DeviceAttributes.Size = LenB(DeviceAttributes)
        Result = HidD_GetAttributes _
            (HidDevice, _
            DeviceAttributes)
           
        Call DisplayResultOfAPICall("HidD_GetAttributes")
        If Result <> 0 Then
            lstResults.AddItem "  HIDD_ATTRIBUTES structure filled without error."
        Else
            lstResults.AddItem "  Error in filling HIDD_ATTRIBUTES structure."
        End If
   
        lstResults.AddItem "  Structure size: " & DeviceAttributes.Size
        lstResults.AddItem "  Vendor ID: " & Hex$(DeviceAttributes.VendorID)
        lstResults.AddItem "  Product ID: " & Hex$(DeviceAttributes.ProductID)
        lstResults.AddItem "  Version Number: " & Hex$(DeviceAttributes.VersionNumber)
       
        'Find out if the device matches the one we're looking for.
        If (DeviceAttributes.VendorID = MyVendorID) And _
            (DeviceAttributes.ProductID = MyProductID) Then
                lstResults.AddItem "  My device detected"
                MyDeviceDetected = True
        Else
                MyDeviceDetected = False
                'If it's not the one we want, close its handle.
                Result = CloseHandle _
                    (HidDevice)
                DisplayResultOfAPICall ("CloseHandle")
        End If
End If
    'Keep looking until we find the device or there are no more left to examine.

    MemberIndex = MemberIndex + 1

Loop Until (LastDevice = True) Or (MyDeviceDetected = True)

If MyDeviceDetected = True Then
    FindTheHid = True
Else
    lstResults.AddItem " Device not found."
End If

End Function

Private Function GetDataString _
    (Address As Long, _
    Bytes As Long) _
As String

'Retrieves a string of length Bytes from memory, beginning at Address.
'Adapted from Dan Appleman's "Win32 API Puzzle Book"

Dim Offset As Integer
Dim Result$
Dim ThisByte As Byte

For Offset = 0 To Bytes - 1
    Call RtlMoveMemory(ByVal VarPtr(ThisByte), ByVal Address + Offset, 1)
    If (ThisByte And &HF0) = 0 Then
        Result$ = Result$ & "0"
    End If
    Result$ = Result$ & Hex$(ThisByte) & " "
Next Offset

GetDataString = Result$
End Function

Private Function GetErrorString _
    (ByVal LastError As Long) _
As String

'Returns the error message for the last error.
'Adapted from Dan Appleman's "Win32 API Puzzle Book"

Dim Bytes As Long
Dim ErrorString As String
ErrorString = String$(129, 0)
Bytes = FormatMessage _
    (FORMAT_MESSAGE_FROM_SYSTEM, _
    0&, _
    LastError, _
    0, _
    ErrorString$, _
    128, _
    0)
   
'Subtract two characters from the message to strip the CR and LF.
If Bytes > 2 Then
    GetErrorString = Left$(ErrorString, Bytes - 2)
End If

End Function

Private Sub cmdContinuous_Click()
'Enables the user to select 1-time or continuous data transfers.

If cmdContinuous.Caption = "Continuous" Then
    'Change the command button to Cancel Continuous
    cmdContinuous.Caption = "Cancel Continuous"
    'Enable the timer to read and write to the device once/second.
    tmrContinuousDataCollect.Enabled = True
    Call ReadAndWriteToDevice
Else
    'Change the command button to Continuous
    cmdContinuous.Caption = "Continuous"
    'Disable the timer that reads and writes to the device once/second.
    tmrContinuousDataCollect.Enabled = False
End If

End Sub