On Wednesday, August 29, 2012 10:07:54 PM UTC-4, Dennis Lee Bieber wrote:
> On Wed, 29 Aug 2012 16:45:10 -0700 (PDT), "Adam W."
>
> I'm a tad curious if using the notation
>
>
>
> b'\x1bA'
>
>
>
> without the .encode() would work.
>
>
>
> My concern is that you may encounter some "string" of data for
>
> printing which the .encode() ends up /changing/ (don't UTF-8 strings use
>
> a high-bit to signal a multi-byte encoding of what had been a single
>
> character?). A pure byte string shouldn't have that problem.
>
Your notation does work, and I was just coming around to reevaluating the use
of the encode because I am getting really odd results when trying to print
lines.
For example I set the byte length to 10 and sent this 500 times or so expecting
to get a solid black bar:
ep.write('\x16FFFFFFFFFF'.encode('utf-8'))
But what I got was a weird stripped pattern... I feel like a lot of my
commands are working by chance, I can't explain to myself why the A in \x1bA
isn't being treated as part of the hex. This stuff always confuses me.
>
> > >>> ep = usb.util.find_descriptor(
>
> > intf,
>
> > custom_match = \
>
> > lambda e: \
>
> > usb.util.endpoint_direction(e.bEndpointAddress) == \
>
> > usb.util.ENDPOINT_IN
>
> > )
>
>
>
> Seems tedious to keep swapping -- does USB support bidirectional
>
> connections?
>
I assigned the input to ep2 to resolve the switching issue.
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