Opening USB HID Device in VB6

[CMiYC]

I'm attempting to open an USB HID device using createfile from kernel32.
The open attempt always fails. This is the call I'm using:

CreateFile(HidName$, &HC0000000, 3, 0, 3, 0 ,0)

HidName$ gets assigned the device:
\\?\hid
#vid_7766&pid_1629
#6&1b9813bf&0&0000
#{4d1e55b2-f16f-11cf-88cb-00111100030}

(its actually 1 string, I entered linebreaks here at the # marks for
readability)

Createfile is defined as:

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

No matter what, the CreateFile call always returns -1. I've tried it with
multiple HID devices to ensure I'm finding the correct device name.

This is VB 6.0 on Win2k.

Any ideas?

-James

[Raoul Watson]

"CMiYC" <cm***@nowhere.com> wrote in message
news:pa****************************@nowhere.com...

I'm attempting to open an USB HID device using createfile from kernel32.
The open attempt always fails. This is the call I'm using:

CreateFile(HidName$, &HC0000000, 3, 0, 3, 0 ,0)

HidName$ gets assigned the device:
\\?\hid
#vid_7766&pid_1629
#6&1b9813bf&0&0000
#{4d1e55b2-f16f-11cf-88cb-00111100030}

(its actually 1 string, I entered linebreaks here at the # marks for
readability)

Createfile is defined as:

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

No matter what, the CreateFile call always returns -1. I've tried it with
multiple HID devices to ensure I'm finding the correct device name.

This is VB 6.0 on Win2k.

Any ideas?

-James

Hi James..

If I recall correctly from my Win98 usb days, I think createfile is async so
it goes back immediately. Did you try putting in a delay for polling?, e.g.:

'Find the device
DeviceDetected = FindTheHid
If DeviceDetected = True Then
'Learn the capabilities of the device
Call GetDeviceCapabilities
' 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