[sane-devel] SniffUSB: URB direction and TransferFlags IN/OUT confusion

[m. allan noah]

On Thu, Feb 25, 2010 at 10:03 PM, Gernot Hassenpflug
<aikishugyo at gmail.com> wrote:
> On Fri, Feb 26, 2010 at 11:56 AM, m. allan noah <kitno455 at gmail.com> wrote:
>> On Thu, Feb 25, 2010 at 9:17 PM, Gernot Hassenpflug
>> <aikishugyo at gmail.com> wrote:
>>> On Fri, Feb 26, 2010 at 12:38 AM, m. allan noah <kitno455 at gmail.com> wrote:
>>>> Do you find that the machine actually makes any control packets once
>>>> it starts scanning? Many scanners only use those at initial
>>>> configuration, which is taken care of by the host OS, and calls to set
>>>> interface, etc. I have found that I generally only use bulk packets
>>>> with most scanners...
>
> Hello,
>
> If it is so simple, should I go for using sanei at once, maybe with an
> existing SANE driver as starting point? I've still got to read up on
> SANE in the next few days. I'll look first at an existing SANE
> backend. I'm not sure what is best since I do not have any particular
> chipset-based backend to go for as first choice. So I am guessing I
> should try using a backend that is as simple as possible.

for initial work, I usually write a small libusb program that just
sends the basic commands required to get image data out. Then I can
play with that program, and watch how the image changes. Once I
understand what each command does, then I pick a backend and clone it.

For simple things, the cardscan backend is nice, but it does not have
all the features of a real scanner. The fujitsu backend might be of
some use, but it is very big and those machines are SCSI based, so you
will have to remove alot of code.

allan
-- 
"The truth is an offense, but not a sin"