[sane-devel] Re: canoscan 5500F driver ?

[Thibault North]

Sorry I did a simple reply :(
I am going to try that, as well as I understood it :) else I'll ask you 
more questions...
Thank a lot for your help,
Thibault

Henning Meier-Geinitz wrote:

>Hi,
>
>On Mon, Apr 12, 2004 at 05:08:27PM +0200, Thibault North wrote:
>  
>
>>ok let's go for a test. But I'am beginning, don't go to quickly :)
>>    
>>
>
>Ok. First: reply to the sane-devel mailing list, not to me personally :-)
>
>  
>
>>You are talking of check-usb-chip.c in sane-backend 1.4pre tools directory ?
>>    
>>
>
>Yes. It's part of sane-find-scanner. It's used by sane-find-scanner to
>find out which kind of USB chip is used. The code tries one chip after
>the other. It first tests for the characteristics of the USB device
>descriptor and interface descriptors (e.g. USB version, number of
>endpoints). If it finds out that the current USB version is 1.1 but
>the vhipset has usually 2.0 it's not that chip so the next test is
>executed. If all the descriptor characteristics are found to be met, a
>short command is sent to the scanner, e.g. to write to a register and
>read that value from it again. If that's also ok, the chip is detected
>for sure.
>
>  
>
>>What do I have to do with it ? how to add a test ?
>>    
>>
>
>Read the source code. You'll see tests for different chipsets. At the
>end of the code, all the different tests are executed one after the
>other. Add one test as mentioned in my previous mail.
>
>Check at which test it fails and have a look at the output of
>sane-find-scanner -v -v. That output contains all the fields the USB
>provides.
>
>  
>
>>Maybe I should read the documentation first... I'll print it now, 
>>perhaps I'll undestand it :)
>>    
>>
>
>Have a look at the USB specification. It explains what all these
>descriptors are and what the balues mean.
>
>  
>
>>Programming: i didn't go far, but I will be pleased to learn more... (I 
>>did a little of C++, but I don't know C structures at all...)
>>    
>>
>
>You'll learn to use them. But in this case, you can just copy the
>already existing tests and change the values.
>
>Bye,
>  Henning
>
>  
>