[sane-devel] On the scanjet 2300C

[Bertrik Sikken]

Jason Anderson wrote:
> I have a log file for this particular scanner.  I believe it is using
> a control transfer.  I also have the control handle.  The only
> trouble is I don't know which function to use.  I've read (most of)
> "USB in a Nutshell", but I still don't know what to do.  I would
> think to use the function "sane_open", however, I don't understand
> the parameters. Sorry for the stupid questions in advance. If anyone
> needs the logs, just look at http://ertain.num1ace.com/usbsnoop1.zip

The HP2300/2400 scanners have come up quite a few times, see for
example the links at
http://www.sane-project.org/unsupported/hp-scanjet-2300c.html

Here is a page that seems to have started a project for it:
http://xoomer.virgilio.it/ovunque-si/linux/english.html

I think I understand the basic transfer protocol for this scanner,
it is mostly the same as in many other scanners and described here
for the HP3300:
http://home.kabelfoon.nl/~bertrik/hp3300c/transfer.html
except the HP2300c seems to do some extra stuff.
(for example it uses URB_FUNCTION_VENDOR_DEVICE type transfers
with value=89 and value=8c)
Looking at the log, there seems to be some regularity in the
bulk data, with the sequence 51 xx 3a 00 3b yy repeating quite
often. I guess xx and yy could be some kind of register index
and data register value.

However, knowing (most of) the transfer protocol does not make
it work yet. You need to know what to transfer ofcourse and this
takes a lot of time and effort to figure out.

All the best,
Bertrik