Re: [Libusb-win32-devel] Using libusb with two or more devices

[Kjell E. A. <kje...@ta...>]

Date: Wed, 04 Jul 2007 10:13:31 +0100
From: Dan Ellis <dan...@ne...>
Subject: Re: [Libusb-win32-devel] Using libusb with two or more
	devices
To: lib...@li...
Message-ID: <468...@ne...>
Content-Type: text/plain; charset=3DISO-8859-1; format=3Dflowed

>Yes, no problem at all.

>Note that Windows only reads serial numbers if they are encoded as US=20
>English. I had my serial numbers encoded as UK English for a long time=20
>and XP wouldn't read them. They've fixed it in Vista. Despite this=20
>libusb was fine with multiple devices with the same VID/PID and UK=20
>English serial numbers.

>If you give your device a serial number (which is read by the OS!) then

>you won't get prompted for drivers if you plug the device into a=20
>different port.

>You should see your devices details added to the registry in=20
>HKLM/SYSTEM/CurrentControlSet/Enum/USB/Vid_xxxx&PID_xxxx/<serial_string
>

>Dan.

Hi Dan !

Thanks for your reply.
I now have libusb working perfectly with two equal devices
simoultanously (they have different serial numbers).

I have done the following observations :

1. First install one device (which has not been installed before), and
WinXP prompts for driver.

2. After succesful driver installation, run this command in a dos box:=20
REG ADD HKLM\System\CurrentControlSet\Control\UsbFlags /v
IgnoreHWSerNum<yourVIDPID> /t REG_BINARY /d 01

3. It is now possible to insert other equal devices in the same USB
port, and WinXP will not prompt for driver.

4. If I insert a device in a different USB port, WinXP prompts for
driver.

I had no success in avoiding step 4 above, googling the subject hints
that it wont be possible. My serialnumber is 5 digits, language code is
0x0409 (US English).

Any comments,

Best regards,
Kjell Eirik