Alt-BEAM Archive

Message #09982



To: BEAM beam@sgiblab.sgi.com
From: Richard Piotter richfile@rconnect.com
Date: Wed, 09 Feb 2000 21:07:29 -0600
Subject: [alt-beam] Algo's FACTory Videos now online


After months, even over a year, promising my video card would arrive
someday... It has come, and I've posted 4 videos of the Algo's FACTory
TV show that aired on some FOX affiliates at the end of 1998. The videos
include the intro (with sound), (and all without sound) Video of Walkman
Jr & Photopopper, BORIS, and the closing credits.

You can reach the Algo's FACTory page from the news item, and from it's
normal place in the misc section.

Also note, that this was a children's educational program, hence the
kids! :)

I haven't made it to TLC or Discovery channel yet! I can only hope! :)
--


Richard Piotter The Richfiles Robotics & TI web page:
richfile@rconnect.com http://richfiles.calc.org

-- Make Money by Simply Surfing the Net or responding to E-Mail!!!
-- Click below!!!

http://www.alladvantage.com/go.asp?refid=ATL147
http://www.spedia.net/cgi-bin/dir/tz.cgi?run=show_svc&fl=8&vid=329630



9983 Wed, 9 Feb 2000 22:15:31 EST [alt-beam] BG micro LED's beam@corp.sgi.com Bumper314@aol.com BG Micro has some very nice looking blue, green, and while LEDs in the LMAD
section for $2.50, its worth checking into

steve



9984 Thu, 10 Feb 2000 14:18:14 +1100 (EST) [alt-beam] Re: walker phototropism beam@sgiblab.sgi.com Ben Hitchcock Oops!

I forgot that you are building a walker. The comments still hold, because
changing the pulse-lengths will still change the gait, but ignore my
ramblings where I say things about left and right motors.

sorry for the confusion,
Ben

> Hi,
>
> > I just got some help from Mark T. on phototropism, and he sent me some
> > info I don't quite understand, so I thought perhaps you could take a whack at
> > explaining what he means to me. Mark T. wrote:
> > "Just take a few photodiodes with resistors in series and introduce them
> > across the coupling resistors of your robot. Depending on the diodes, how
> > they are pointing, and how your robot's mechanics are arranged, you can
> > figure out how to give your critter eyes."
> > I am trying to build a two motor bicore phototropic walker (eventually
> > with reverser). Can please explain what Mr. T mean's (and think 'see spot
> > run' language, I am really not an engineer). Any help would be appreciated.
>
> You probably already know that changing the resistor values on your
> bicore will change the timing of the cycle. That is, if one resistor is
> larger than the other, then one neuron will turn on for longer than the
> other one. If each neuron controls a motor, then the bot will take longer
> steps in one direction than the other direction, resulting in it turning
> around in circles. Much like walking with a limp, really.
>
> Anyway, what Mark was saying is that you can turn a photodiode into a
> variable resistor. Imagine that when the bot is pointing left of the
> light, you make the left motor turn on for longer than the right motor,
> and when pointing right, make the right motor turn on for longer. You
> will have a robot that will turn towards the light, and set off on a trek
> into the sunset.
>
> To make the resistors be affected by light, grab a photodiode, attach a 1
> Meg resistor to it, and attach the other end of the resistor to an input
> of a neuron in the bicore. Ground the other end of the photodiode.
>
> Now changing light levels will make the on-time of that motor vary,
> depending on which way around the PD is, and how your bicore is set up.
>
> Repeat for the other neuron in the bicore, point your PDs in different
> directions, and voila! Your bot will be AFFECTED by the direction of the
> strongest light source. It might run away from it, it might head towards
> it, it might head at 90 degrees from it. Now comes the time for physical
> experiments, which is what Mark was talking about.
>
> hth,
>
> ben
>


--
Nothing is foolproof to a sufficiently talented fool.



9985 Wed, 9 Feb 2000 22:23:32 -0500 [alt-beam] Walker Tutorial. Any info you want included? "Dennison Bertram"
Right now I'm writing a paper about how to build a two-motor walker. I'm
writing this from a collection of my own notes and findings. If there is
anything else that you would like to know about, let me know and I'll try to
include it.

dennison

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