USB device driver development tips [Was Intraoral camera and sane]

[Mayuresh <mayuresh%acm.org@localhost>]

On Sun, Dec 13, 2020 at 12:33:17AM +0530, Mayuresh wrote:
> I have been maintaining a Virtualbox Windows VM just to operate an
> intra-oral X ray device [1] that has Windows-only drivers. Looking for
> liberating it from Windows if possible.

I had a discussion thread on sane-devel mailing list as the device is
detected by sane-find-scanner but there is no backend to it. I shared
details like wireshark and usbmon traces, though the list members could
not relate it with any pre-existing protocol - requiring me to reverse
engineer it myself. There is no help available from the manufacturer or
the retailer.

I'd like to liberate the device from proprietary Windows-only software.
Would prefer NetBSD or Linux as 2nd choice to have my own way of scanning
the DICOM images the camera produces on exposure to x rays.

On Linux I have tried playing back the interactions shown by wireshark
using python libusb package. But have only got input/output errors or
timeouts.

Further, the 'ENDPOINT' numbers reported by usbmon and wireshark for the
same interaction are different and that is a bit baffling.

If I were to try NetBSD to mimic the wireshark intercepts, is devel/py-usb
a good choice or are there any other libraries recommended?

Any other tips and tricks will be useful.

If someone wishes to take a look at the wireshark snapshots they are here:
http://mayuresh.sdfeu.org/snaps3.pcapng.gz

lsusb details shown on Linux are here:
https://alioth-lists.debian.net/pipermail/sane-devel/2020-December/038619.html

-- 
Mayuresh