Alt-BEAM Archive
Message #08049
To: beam@sgiblab.sgi.com
From: Dave Hrynkiw dave@solarbotics.com
Date: Mon, 29 Nov 1999 08:33:34 -0700
Subject: [alt-beam] Re: Different approach to ground feelers. Useful?
At 06:18 AM 11/29/99 , J Fisher wrote:
>It's basically a plan for a simple, short-range light-based range-finder,
>suitable for detecting that the bot is about to walk off a cliff and that
>it should back up instead... The concept is very simple (see 2k gif
>attachment), but implementing it might be deceptive. (It's a laser dot
>projected onto the ground at an angle such that the position of the dot
>relative to the bot hull indicates the height of the ground immediately
>ahead. It's a little bit like the two spotlights method used by the dambusters.
It's a GREAT concept, one I've seen in use by (sigh...who else?) Mark
Tilden already. I saw a module he bread-boarded about 3 years ago that used
a super-high intensity LED as a "link" in a microcore setup. (I'm going
from memory here, plus my own experiment using his circuit).
It had a "spot" LED that bounced it's light off the surface, which was
received by a sensor in a tube. (Just spent 15 minute searching
unsuccessfully for notes). I believe the LED Tx/Rx (transmitter/receiver)
took the place of one of the linking resistors in a 2 neuron microcore
(coulda been bicore?). If there is no reflection, it reads "ifinite"
resistance, and does not pass the pulse train. If in "appropriate" range,
it passes the oscillation pulses, but if it's TOO close, it "locks" on in a
steady on condition, like if a Nv resistor is much lower than the rest in a
microcore circuit. It gave him a simple, effective 3-state output optical
sensor.
I'm pretty sure he's using a modified version of this on his
"Bigman/Roswell" walker, utilizing IR modulation and Sharp OPIC sensors for
receivers.
If I find the notes, I'll contribute them to the list....
Regards,
Dave
---------------------------------------------------------------
"Um, no - that's H,R,Y,N,K,I,W. No, not K,I,U,U, K,I,_W_. Yes,
that's right. Yes, I know it looks like "HOCKYRINK." Yup, only
2 vowels. Pronounciation? _SMITH_".
http://www.solarbotics.com
8050 Mon, 29 Nov 1999 12:32:10 PST [alt-beam] Stepper Motors?? beam@sgiblab.sgi.com "Pete McCarthy" Hello Everyone,
My friend gave me a couple stepper motors, and I'm not sure what to do with
them. Does anyone know how to use stepper motors or can anyone direct me to
a tutorial on how to use them??
-Pete
______________________________________________________
8051 Mon, 29 Nov 1999 14:54:34 -0800 [alt-beam] Re: Stepper Motors?? beam@sgiblab.sgi.com Greg Powell At 12:32 PM 11/29/1999 PST, you wrote:
>My friend gave me a couple stepper motors, and I'm not sure what to do with
>them. Does anyone know how to use stepper motors or can anyone direct me to
>a tutorial on how to use them??
http://www.aaroncake.net/circuits/stepper.htm
http://werple.net.au/~tonymerc/steptheo/stepbas1.htm
Cheers,
Greg
http://www.engr.uvic.ca/~gpowell/
Home