[sane-devel] backend in progress: canon i-sensys mf4570dn, 'mfnp' protocol

[Louis Lagendijk]

hello Chris,
sorry for the delay, but I am quite overloaded with work $DAYJOB, and am
working on porting some other program stack to MacOS.

On Sun, 2011-02-27 at 16:32 +0100, chrysn wrote:
> On Fri, Feb 25, 2011 at 10:45:35PM +0100, Louis Lagendijk wrote:
> > Is there a backend that supports your device? If so, I could have a look
> > at some packet traces to see if support for your devices IP-protocol is
> > doable.
> 
> there is no backend that autodetects the device when on usb or ethernet,
> none that is supposed to support it according to its description, and
> the characteristic sequence of the protocol ('MFNP') i recorded from the
> windows drivers is not found in the backend sources.
> 

> > I developed the code using an MP970 that died. I am now using an MP980.
> > But the code works on a lot of devices using an ethernet or even
> > wireless connection. Again, does the device work over USB?
> 
> it does have usb, and is supposed to scan over usb as well, but i didn't
> dig too deep there because i'd use in on ip in practice. also, sniffing
> usb is a bit trickier than sniffing ethernet, and i'd need another
> virtual machine environment to do it.
> 
Please post the output of sane-find-scanner with the scanner attached
through USB. What chip is detected? Once we know if one of the existing
backends can be made to work over USB, I can have look at integrating
the MFNP stuff (which looks like USB over TCP!) in that backend. The
mfnp looks similar to BJBP, except for the last few packets, but that
may be an extension to read the buttons.

I had a quick look at the scanner protocol traces embedded in the TCP
packets, but they don't look faniliar to me, so this may not be a
scanner supported by the pixma backend (Nicolas, could you please have a
look if this looks like something familiar to you, as usual the USB data
starts at byte 16 after the USB over TCP header)?

> > Not that I know of. Does python allow for an easy wrapping of
> > C-libraries?
> 
> basically it does, and i've seen it has been attempted once, but there
> is no further information than [1]. i've seen there is a network
> backend as well; implementing that interface would probably be easier
> and more portable.
> 
> [1] http://mail.python.org/pipermail/python-list/2006-March/977748.html
> 
This does not look a very attractive route for integration in Sane to
me. Lets first see if sane-find-scanner recognizes the scanner when
attached over USB. It is quite likely that a well-known chipset is used
that is already supported by one of the existing backends. If so, and
the backend is patched to work with your scanner, we can look at USB
over TCP.

best regards, Louis