[sane-devel] Re: Canon N670U (Siegfried Löffler)

[Theodore Kilgore]

On Tue, 29 Jan 2002, Philip Underwood wrote:

>
> > Message: 2
> > Date: Mon, 28 Jan 2002 22:06:34 +0100
> > From: Siegfried =?iso-8859-1?Q?L=F6ffler?= <siegfried.loeffler@gmx.net>
> > Reply-To: siegfried.loeffler@gmx.net
> > Organization: Private
> > To: Sane-devel@mostang.com
> > CC: Theodore Kilgore <kilgota@banach.math.auburn.edu>
> > Subject: Re: [sane-devel] Canon N670U
> >
> > This is a multi-part message in MIME format.
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> > Content-Transfer-Encoding: 7bit
> >
> > Hi,
> >
> > as the LM9833 chip used in the N670U should be backward compatible
> > to the LM9832/1 in the plustek backend, in theory it should not be
> > a big deal to make the N670U work.
> The only real difference is in the calibration routines - you would need to
> change on of the constants to account for the fact that the lm9833 returns 16
> bits as opposed to 12.
>
> However, there are a lot of parameters that you need to know to make the thing
> work properly - stepper motor distances, timing things etc - you can normally get
> these by USB snooping - at least that's what I did for the epson 1250 driver.
> >

Ah, if I just knew how to extract such data from the snoopy log...



> > However, in practice I did not manage it yet.
> >
> > What I did so far:
> >
> > I tried to find out the parametrs for the N670U by
> >
> > a) reading the NS LM9833 datasheet, available on the National Semiconductor
> > Website
> >     as well as some useful information on http://connect.to/merlin/
> >        (information on the former versions of the LM9833 as well as source
> > code)
> >
> >     and the URL mentioned by Gerhard Jaeger
> >         http://scanjet2200c.sourceforge.net/ns-twain/
> >
> > b) looking intensively at a trace made under Windows, using "USB Snoopy".
> >
> > In particular, I tried to make an entry in the plustek-devs.c based on the
> > parameters seen in the USB Snoopy Log File. But: Despite some small
> > progress (in the beginning, I always ended up stalled with an error when
> > trying to read register 7) I do not suceed to switch on lamp or motor of
> > the scanner yet.
> Sometimes the lamp isn't actually connected to the lamp outputs on the chip.
> Sometimes it's connected to one of the misc i/o pins. Helpful:)
> >
> > I also tried to run the driver on scanjet2200c.sourceforge under Windows,
> > but strange enough, I did not succeed to make that one work neither. (I get
> > an error that register 0x07 can not be read). So now I somehow wonder
> > whether there could be something particular inside the N670U. However, I do
> > not dare to open the device. Maybe somebody had opened it and could help by
> > describing what else (besides the LM9833) is on the mainboard?
> That sounds odd - I wonder if there's a problem with the USB setup somewhere?
>
> >
> > As I am currently quite busy with other stuff, I am afraid it might take
> > some time until I will be able to continue the tidious research studying
> > the USB Snoopy logfiles...
> Could you send me a copy of the logfiles - I'm trying to get a base together that
> will run any lm983[1/2/3] based scanner, with the hardware specified in a
> configuration for each scanner supported. Early days yet, though.
> >
> --
> Phil Underwood.
> Curing disease, illness, and little flaky bits throughout the North-West
> --
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