[sane-devel] genesys backend

[John William Dalton]

I've managed to get sane/xsane working with my Canon LiDE 60.

I did this by compiling the experimental CVS genesys
backend (including Pierre's recent support for the LiDE35/40/50).
Before compilation I replaced every instance of the LiDE 35
USB ID (0x2213) with the USB ID for the LiDE 60 (0x221c).

I tested preview mode and scanning at 75dpi, 150dpi, 300dpi, 600dpi,
1200dpi and 2400dpi.  All worked.

There were  a few minor issues noticed.  Unless mentioned the
scan area was set to 'full':

1) In some modes there is a 'klunk' noise after the scanning head
finishes scanning and before it starts its return journey.
Possibly the scan head is travelling just a little too far
and hitting the end of the track? This 'klunk' is not there when
the same operation is done under windows.
The nature of the klunk varies with the scan mode as below:

Preview: soft klunk

75dpi: soft klunk

150dpi: nasty klunk and short grinding noise as the scan head hits
the end of it's travel.  I think the grinding noise is the gear
drive of the scan head skipping a couple of teeth as the scan head 
can't go any further.

300dpi: no klunk.  Nice and smooth.  If the scan area is set to the
bottom quarter of the page, there is a 'klunk' as the scan head reaches
the end of its travel.  The scanning is a little noisier than windows
(but it's faster??)

600dpi: no klunk.  The stepper motor makes a medium noise.  Under
windows it is audible, but much a quieter low level hum.

1200dpi: no klunk.  The stepper motor makes a lot of noise.  Under
windows it is almost silent.


2) Before each scan the scan head spends some time dithering backwards
and forwards, before commencing the scan.  Some sort of a calibration
run?  Under windows the scanner does not do this.  I did observe though
that when the windows software was installed it spend a minute or so
doing a calibration run and storing the results.


I'm not sure if the above issues are LiDE 60 specific, or also
present with the LiDE 35.  Either way, the driver seems to be a great
piece of work and just needs some fine tuning for the LiDE 60.

When I get a chance I'll try a usbsnoop on the windows driver,
put the log on my website and post a link.  (I gather you are
experienced at reverse engineering USB logs Pierre?  Do you
have any interest in looking at an LiDE 60 log, or guiding me
though the process?)

I also plan to do an audio recording of the scanner driven by both
sane and its windows drivers.  Hopefully I can then accurately
compare scan times and by doing an FFT, and looking at the audio
spectrum, figure out whether there is any difference in the rate
at which the stepper motor is being driven.


An additional issue.  When xsane starts up, it presents a list
of found scanners for em to chose from.  The LiDE 60 does not appear
in this list.  I have to explicitly provide the device 
genesys:libusb:005:006, as reported by sane-find-scanner, on 
the xsane command line.  Does anyone know how to get a USB scanner
to appear in the list of available scanners?

Regards
John


On Fri, 2005-10-14 at 16:07 +0200, Pierre Willenbrock wrote: 
> Stretched that "shortly" a bit. Canon LiDE 35/40/50 support is now in
> experimental cvs.