[linux-elitists] USB knobs and buttons.

Seth David Schoen schoen@loyalty.org
Fri Aug 1 00:49:01 PDT 2003


Nick 'Sharkey' Moore writes:

> You could look at <http://www.dontronics.com/dlp.html> this sort
> of module, which gives you eight bidirectional I/O pins.
> 
> Or if you need something way more complex, you could use one of
> the microcontrollers with USB on 'em.

Hmmmm, those look really nice.  It sounds like it's about time for me
to learn USB.

One problem is that their high-end device can only do about 800
characters per second.  (Maybe I just didn't look through enough data
sheets; that was the only number I could find easily.)  I currently
don't have an application which needs more than that, but it sounds
awfully slow in comparison to a modern bus speed.  Is there a cheap
USB device which does faster parallel digital I/O?

I'm somewhat familiar with analog I/O boards, which are a whole other
can of worms.  I'm busy all the time trying to stop them from being
made illegal.

The GNU Radio folks have just put together an external fast ADC/DAC
peripheral which is supposed to be on sale soon.  Unfortunately, its
bandwidth is apparently still a little too low for TV applications,
but perfectly suitable for many interesting software radio projects,
including receiving several FM stations at once.  (Most people spend
their effort trying to build FM receivers which _reject_ adjacent
channels... but not the GNU Radio people!)  So there's something nice
coming up for pretty fast analog I/O, but what about digital?

-- 
Seth David Schoen <schoen@loyalty.org> | Very frankly, I am opposed to people
     http://www.loyalty.org/~schoen/   | being programmed by others.
     http://vitanuova.loyalty.org/     |     -- Fred Rogers (1928-2003),
                                       |        464 U.S. 417, 445 (1984)



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