The 8400f is reported to have a GL843 processor. Study the source code of the genesys backend. You may be able to clone the settings of an existing supported GL843 scanner. https://help.ubuntu.com/community/CheckIfScannerIsClone
Stef Voltz maintains the genesys backend and may be able to help you. Jack On Mon, Aug 29, 2011 at 7:41 AM, Alejandro Imass <ait at p2ee.org> wrote: > On Mon, Aug 29, 2011 at 5:01 AM, Chris Molanus <chrismolanus at hotmail.com> > wrote: >> Hi, >> I would like to attempt to create backend support for the Canon CanoScan >> 8400f Scanner. >> I am finding it difficult to to find information on how to start as I have >> never done this before. >> I can program in C but have no?experience?in writing back end drivers. >> Can anyone point me to some information are tell me a good place to start? >> Chris >> -- > > There are already some Canon ADF drivers that work pretty well. The > process is not that simple as there are a lot of details regarding > mechanical movements, sensors and there is always the possibility of > damage to the device while developing. > > The usual method is to snoop the comm between the OS and the scanner > by using the officially supported driver in the supported OS, e.g. the > Windoze driver. Is the interface is USB you can use the USB Snoop > program and capture a sample scan of a black and white page and then a > color one. Your test subjects should be large rectangles of color > and/or black so it makes it easier to identify the image data block. > > It's a painstaking job but you need to figure out the protocol first. > You will need background into many subjects of which C is probably the > least of your worries. Before you talk to the scanner in Linux you > need to understand about the USB subsystem, probably deal with libusb, > udev and/or hal (a.k.a. hell ;-) ) and many other layers of software > and options that Sane handles. Remember that Sane runs on many types > us *nix set-ups so there are *many* options and paths to talk to the > hw. > > I wanted to build a driver myself a few years ago, but even with 23 > years of work experience in the field, I decided to hire someone from > this list and then just helped to snoop, test, debug and even hack the > driver a little bit. ?This experience taught me the basics of sane > driver building and hacking and I can now appreciate some of the > complexities of this. Of course, given enough time, you will > eventually become an expert, but at least in my case I usually don't > have much free time to head-bang at something that requires a very > wide of skills and I'd rather focus my time on the expertise I already > have. YMMV of course. > > Your best option IMHO is to download the Sane and Sane Backends source > code and look at the existing Canon drivers. Who knows, the current > drivers may even work with the 8400f, and you could contact the author > of some of these drivers directly and perhaps they could dedicate some > one-to-one time which you'll probably have to pay for but in my case > it was completely worth it. > > Hope this helps, > > -- > Alejandro Imass > > -- > sane-devel mailing list: sane-devel at lists.alioth.debian.org > http://lists.alioth.debian.org/cgi-bin/mailman/listinfo/sane-devel > Unsubscribe: Send mail with subject "unsubscribe your_password" > ? ? ? ? ? ? to sane-devel-request at lists.alioth.debian.org >
