As David pointed out, once you plug the mass storage device in, the
computer expects the file system to remain static.

I suspect that implementing a network driver that works across several
operating systems is going to be non-trivial, since the USB network
class is not nearly as well defined as the mass storage class.

Unfortunately, I don't know of another easy method to make the device
accessable without OS specific drivers, which may be your goal.  At
least not another way that isn't terribly hackish.

However, it's worth trying out, to see how each OS handles a mass
storage interface that changes.  Go ahead and make the MSD device, and
have a 'virtual' file on there.  The file contents will be derived
from, perhaps, an internal running counter, and will be fed to the
computer whenever it requests that particular block of information.

See if reloading the file requests the data again.  There may also be
some settings in the USB mass storage class that force the computer to
not cache information (useful for security reasons).  You may also
have the option of setting up the cache timing - making it so it won't
delay file system writes, for instance.  Then you could use javascript
to change files on the device, which would allow a two-way mass file
system interface. (There is a USB wiki that does this - no need for a
server or software to edit files).

Still, it seems like you'd run into endless issues trying to do this
in a way that would work on several different systems.

Python and a serial endpoint seem to be a better solution...

-Adam

On Fri, Oct 16, 2009 at 10:37 PM, Harold Hallikainen
<harold@hallikainen.org> wrote:
> I'm wondering about combining the USB mass storage class and =A0the HTTP
> server in the Microchip TCP/IP stack. When someone plugs in a host
> computer, the MSD appears on their machine. Click on index.html, and
> you're at the user interface. Or, it could even include an autostart
> file to start the =A0browser. You could, of course, look at files and
> MAYBE even do GET cgi or MAYBE even POST.
>
> Possible? Bad idea?
>
> Thanks!
>
> Harold
>
>
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