[sane-devel] Help on HP Phostosmart S20

[Jonathan Buzzard]

evilio at vodafone.es said:
> I am trying to write a driver for the HP Photosmart S20/S20xi photo
> scanner (http://www.sourceforge.net/projects/hps20xi ).

The way this scanner works under Windows is that there is a .DLL
that converts the HP SCL commands into a very complex USB protocol.

I would suggest the best way to reverse engineer this scanner would
be to get the documentation on the HP SCL commands, and prod the
scanner under Windows while logging the USB traffic. If necessary
write a Windows program to send specific HP SCL commands so you
can capture the USB protocol for each command individually.

The alternative is to disassemble the DLL and work out how it
how it mugs the HP SCL commands in to the USB protocol and replicate.

You might find that a combination of both methods is the best.
Knowing what

A third method would be to do something similar to the CaptiveNTFS
driver, though this would only work for x86 Linux.

Knowing what stepper motor is used is near to useless information
and will not particularly help you advance a SANE backend for the
scanner.


JAB.

-- 
Jonathan A. Buzzard                 Email: jonathan (at) buzzard.me.uk
Northumberland, United Kingdom.       Tel: +44 1661-832195