At 07:32 PM 11/18/97 +0200, you wrote:
>Have you checked out what the guys on the comp.robotic.misc discussion group
>are suggesting for your propeller clock? Sounds _very_ interesting!

I only caught a small piece of the thread, but the idea of making the pc
board out of fractal mech seems a little out of the reach of most hobbiests
:-)

Cool idea about the setting mechanism, though. For those who don't want to
venture into news, the idea was to make the propeller clock have a "virtual
keyboard" sense fingers in proximity to the floating numbers. Pointing to
the top of a digit would advance it, to the bottom would decrement it. A
few different methods were suggested. I think the minimalist approach would
be best. My method would be to use the LEDs themselves as photodiodes.
Unfortunately, with the input "1" threshold of a PIC at well over 1 volt, I
doubt if there would be enough reflected light off a finger from adjacent
LEDs to forward bias an LED as a photodiode up to 1 volt, even if it was a
really clean, low leakage one.

Also, first time I read a newsgroup in more than a year. The PICLIST puts
any newsgroup to shame. The signal to noise ratio is better here, even when
people forget to ignore useless threads and reply when they really know
better. The whole thing about binaries has wasted at least as much
bandwidth as the original, but not quite as much as the "good times" virus.
Please, everyone, don't reply to any post that's off-topic just to voice an
opinion or call someone a bozo... oops, I just voiced an off-topic opinion.
See, it's too easy to do.

On-Topic:

An update on the H-bridges: I found another ROHM distributor, who
overnighted me their motor driver databook. They make lots of nice chips,
most of them draw very little current at idle, unlike the L293 series that
have been so popular with robot builders and PICsters.

I'll let the list know where and what I come up with. An H-bridge for $0.30
that draws 400uA idle sounds good to me, they make them, I just need to
find a distributor who will sell in 1000 lots instead of 100000 lots. The
BA6208 is one of the cheaper ones, that does forward, reverse, and brake,
and has inhibiting circuitry to prevent "all-on" conditions. The inhibit is
nice while debugging your code :-)

Cheers,

Bob

http://www.bobblick.com/