Re: [pyusb-users] not finding Arduino or mouse devices

[Xiaofan C. <xia...@gm...>]

On Mon, Mar 5, 2018 at 3:51 AM, Michael Hennebry
<mic...@ri...> wrote:
> I might end up using pyserial.
> It can find the VID/PID of CDC virtual serial ports.
>
> That said, I'd still like to be able to use pyusb.
>
> At the suggestion of a colleague,
> I used zadig to get avrdude to work,
> Didn't really know what I was doing.
> Just followed directions.
> At one time, I had avrdude and Atmel Studio working,
> but I do not know what I did.
>
> My effort to get pyusb to work seems to have damaged AS7.
> It can no longer use the Atmel ICE.

Because Atmel ICE needs to use vendor driver whereas
avrdude uses libusb-win32 or libusb-1.0 supported driver.

In order to use Atmel Studio and avrdude, you may have
to switch driver between the two. Or try usbdk.

> libusb-1.0 is a dll that applications, e.g. python can open?
> WinUSB, libusbK.sys, usbk and generic HID are used by the OS?
>
>> But if you really want to try, you can try libusb usbdk backend,
>> which may work with your CDC device. It acts as a filter driver.
>
> usbdk is a dll that applications, e.g. python can open?

No. usbdk.sys/WinUSB.sys/libusbK.sys are Windows kernel
drivers that Windows OS needs to have to access your device.
That is low level stuff. To make it more complicated,
usbdk/winusb/libusbk also have associated user space library
(DLL) to let you access the device.

libusb-1.0.dll is the user space library on top of the
usbdk/winusb/libusbk for you to easy access the device.

pyusb can use libusb-1.0 backend through libusb-1.0 library.
Under Windows, libusb-1.0.dll is the file name for the library.

> https://github.com/libusb/libusb/wiki/Windows#How_to_use_libusb_on_Windows:
>> HID keyboards and mice cannot be accessed using the native HID driver as
>> Windows reserves exclusive access to them.
>
> No user application can see either HID mice or HID keyboards as
> USB things?
> Presumably an application can see the keyboard as a file it can open.
> What can see a mouse?  As what?

There are APIs for mouse/keyboard, like Direct Input. There are
on the high level than USB. They support USB/Bluetooth etc.

> Thank you for your attention.
> I hope it doesn't seem too much like irrigating a rock.
>

Windows driver is a complicated world...

-- 
Xiaofan