[sane-devel] Canon D660u uses Merlin chipset (-->plustek?)

[Henning Meier-Geinitz]

Hi,

On Sat, Jul 05, 2003 at 08:06:02PM +0000, jollyprince@juno.com wrote:
>> We know, you have mentioned that fact more than once :-)
>> But what's the connection to the article about the Canon D660u you are
>> responding to? As you yoursef wrote, the visioneer 5800 uses a
>> Realtek, not a National Semiconductor chip.

> I had been advised to model any backend that I would write after the
> Plustek project, that's all.

I think that was because we thought your scanner is based on the E5
chipset which was thought to be a National Semiconductor LM9832. But
that is not true, it's realtek. So the plustek backend is not of much
use. You can use it as a general example of an USB backend but not
much more. It's pretty complex so looking at a simpler backend like
ma1509 may make more sense.

>> Have you already asked Realtek about programming information for that
>> chip? What about Visioneer?
 
> No, i was led to believe this was hopeless.  Are you saying , not necessarily so.

I don't know any of these companies. When I contacted Mustek, I got
good responses, even the Windows source code for some scanners. Some
other manufacturers also cooperate so I would just try it. It may be
difficult to get the right contact addresses, however.

>> Have you read the documentation you have been ponited, to? E.g. 
>> http://www.meier-geinitz.de/sane/misc/unsupported.html
>> http://www.meier-geinitz.de/sane/misc/develop.html
>> and
>> doc/backend-writing.txt?
> 
> Yes, I'm currently in a state of information overload and I'm saving
> everything I can get my hands on.  Right now, I'm trying to be more
> productive than that.  I'm at the crossroads.  I may well be better
> served to go shopping for a different scanner,

That will be definitely easier.

> but I simply don't know at this point.  With the information and data
> I already have maybe I can start, but I just don't know for sure.
> I've never done anything like this.
> 
>> In your case I'd start with trying to capture the USB commands send to
>> the scanner using one of the methods explained in the docu.
> 
> Now you're talking!  Where do I start?

Well, I just wrote it in the above sentence. Capture the USB data. The
methods how to do that are mentioned in the develop.html web page.
Also have a look at the recent discussions on sane-devel on the hp2300
scanner. While that scanner is different, the guy who wants to write
the backend also captures the commands the windows driver sends to the
scanner.

Bye,
  Henning