Alt-BEAM Archive
Message #13707
To: BEAM beam@sgiblab.sgi.com, Twin Cities Robotics Group tcrobots@orbis.net
From: Richard Piotter richfile@rconnect.com
Date: Wed, 19 Apr 2000 22:39:20 -0500
Subject: Servo Controler
I was planning on using a BASIC Stamp IIsx To run Quadrapod temporarily
to get it done before the end of the school year, however due to much
fustration attempting (unsucessfuly) to comunicate with it with the PCs
at my colege, I've decided to fall back on the original BEAM controler.
With the wonderful world of school resources, I will be able to finish
populating the PCBs by simply picking and choosing what I need from the
shelves there.
The one limitation, unfortunately, is I do NOT want to modify the servos.
My question is how stable is the frequency that a bicore produces. I
want it to generate the PWM to drive the servo. I want to use a variable
bias with 2 inputs that would have 4 actions. Hold servo, CW, Center,
CCW. The 3 positional actions would be adjustable by variable resistors,
so the system could be fine tuned. The 4th pulse would need to stop the bicore.
I have ideas on how to do it, but I'd realy like to hear the expiriences
of anyone else who may have tried similar systems. If there were any
problems, things that should be considered, or if it has been done so I
don't need to redo it.
The inputs and outputs required are as follows:
Input Output
A B X
--------------------
0 0 Position A
1 0 Position B
0 1 Position C
1 1 Servo Hold
Each position would be set by a variable resistor. The question here is
how much the other variable resistors will effect each other, assuming
that the other resistor positions with the high signal will look like a
voltage divider, so adjusting one would likely effect the others, right?
The hold servo position would need to interupt the bicore pulse. I'm
thinking a simple pair of AND gates can carry out that task just fine.
AND on the 2 inputs, AND on that output and the output of the bicore.
Hope I can get some advice here. Thanks!
--
Richard Piotter The Richfiles Robotics & TI web page:
richfile@rconnect.com http://richfiles.calc.org
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13708 Wed, 19 Apr 2000 22:43:41 -0500 Servo Controler Twin Cities Robotics Group , BEAM Richard Piotter Hey, it just occured to me, wouldn't diodes effectively isolate the
variable resistors, so only the ones with a negative charge would have
an effect on the bicore circuit?
--
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
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13709 Wed, 19 Apr 2000 23:57:59 EDT Solarizing beam@sgiblab.sgi.com turtletek@aol.com Ok, here we go again.
Does anyone know if the Ucoba* can be solarized using the Chloroplast SE**?
I know of the PM1, the D1, and the 1381 DLSE for solarizing. Are these as
effective as the Chloroplast? Which do you prefer/recommend?
What can and can't the Chloroplast solarize? And if you don't mind, why? If
these are too many questions, don't feel pressured to answer them all. Any
answer whatsoever is appreciated.
*(http://www.geocities.com/ResearchTriangle/Node/3904/pictures/ucoba.html)
**(http://members.home.net/cybug/Chloro/chloro~1.htm)
Many thanks (I hope),
-Brien the TurtleTek
www.extremesc.com/turtletek/beam
13710 Wed, 19 Apr 2000 23:20:24 -0500 Servo Controler Twin Cities Robotics Group , BEAM Richard Piotter Does this circuit look decent?
1x 74HC14 (6 inverter gates)
1x 74xx00 (3 NAND gates)
1x 74xx08 (2 AND gates)
3x Silicon Switching Diodes
3x Multiturn Potentiometer
2x Small Value Resistors
2x Capacitors
___
,----|>o--| \
| | |o--|<--o--/\/\/---.
| o--|>o--|___/ | ^ |
| | |____| |
| | ___ |
o----|>o--| \ |
| | | |o--|<--o--/\/\/---o
| o-------|___/ | ^ |
In | | |____| |
A | | ___ |
O--o---------| \ |
| | | |o--|<--o--/\/\/---o
O----o--|>o--|___/ | ^ |
In | | |____| |
B | | ___ |
o---------| \ |
| | |--. |
'-------|___/ | ,--/\/\/--o--/\/\/--.
| | |
| o----|>o-----||-----o
___ | | |
/ |--' '-----||--o--o<|----'
O------------| | |
Servo \___|------------------'
--
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!!!
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13711 Wed, 19 Apr 2000 23:23:02 -0500 (CDT) Re: efficient launcher? beam@sgiblab.sgi.com "Jonathan B. Cage" Interesting. Btw, I love potato guns. Although I'm a total BEAM newbie
(saw it a couple weeks ago and am just ordering stuff for my first
photovore), I was thinking about some sort of combustion mechanism like
this. What I was thinking involves a couple
small carbon rods (from old batteries) and water. If you connect a carbon
rod to both the positive and negative terminal (so one rod per terminal)
of a battery and submerge them in water, the currect will actually
separate the hydrogen and oxygen in the water. Then you could
ignite it with a spark from some piezo element. However this process is
extremely slow. I know a 9V battery can separate enough hydrogen to
create quite a little explosion in a 1 inch square container in about 20
minutes. This probably isn't very practical for solar powered
applications, but it maybe could be used as an emergency escape mechanism
or weapon by a bot. Sort of along the same lines as insects employ
chemical defense weapons.
My 2cents
-Jonathan
On Wed, 19 Apr 2000 Meabadboy@aol.com wrote:
> In a message dated 4/19/2000 12:57:52 PM Eastern Daylight Time,
> phillip@ryals.com writes:
>
> << But what about a launcher? I
> really don't think there's an efficient way to do it with a solenoid or
> motor... >>
>
>
> Have you thought of something along the lines of the old "Potato gun" idea ??
>
> you could use a combustion chamber that is fueled by a main tank and ignited
> by a charge ~ something like a starter on a gas grill.
>
> (see attached sketch)
>
> You could fill a small chamber with a modest amount of fluid ~ like lighter
> fluid ~ from a main tank ~ the grapple could be pulled into place by the
> winch and mechanically slid into the chamber ~ then launched ~ and then
> retrieved by the winch ~ to be launched again and again until the fuel supply
> is gone ~ but that too could be refueled by the bot by when it indicates a
> low level it could return to a fueling station.
>
> Just a thought
>
> Steve
>
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