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

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