Alt-BEAM Archive

Message #12677



To: beam@sgiblab.sgi.com
From: SkavenArmy@cs.com
Date: Tue, 28 Mar 2000 23:37:40 EST
Subject: [alt-beam] Re: identification problem


has what he thinks is a trim pot too , but it came from an old fm/am/tape
radio..also i have a mic with 2 leads that i dont knwo what klind it
is......the 3 lead thinies have a metal top and are not dot leads , but
flattened

jay z



12678 Tue, 28 Mar 2000 23:47:33 EST [alt-beam] Re: Allmost complete walker. still not working beam@sgiblab.sgi.com SkavenArmy@cs.com wwww.geocities.com/jaydzink
this is my new page on beams and electronics and robotics...and maybe some
cuervo gold...who knows.....



12679 Wed, 29 Mar 2000 00:40:39 EST [alt-beam] glider beam@sgiblab.sgi.com SkavenArmy@cs.com i am goingto make a glider using a basic 2 stamp , carrier board and 2 or 3
servos ....... i want it to be fully automated so that when it hits a certain
altitude it slams on full flaps and goes into a flatspin to the
ground,landing genlty....also ... i want it to be able to be pre programmed
to do certain things at certain altittudes.like maybe start a rocket
engine(composite carbon rocket motors) etc etc.....simple i/o lines would
work im sure , but the one reason i dont have it already, is that i cant
afford the basic 2 stamp...if anyone has any info on maybe warping the
"sacred" bicore or maybe even dissecting a basic 1 or 2.......thankx
jjay-z
ohio



12680 Wed, 29 Mar 2000 00:23:01 -0600 [alt-beam] Portable AV monitor for Quadrapod BEAM , Twin Cities Robotics Group Richard Piotter I'm about half finished with my portable AV monitor for Quadrapod. I
have the video display complete. Now I have to build the audio portions
of the display. I'm likely going to have a keypad on the front, on
either side of the screen. Two directional pads (like on a game system,
for the purpose of robot and head movement (camera is on the head). I'll
also have some other vaarious functions. The speakers are already
installed, but I havn't finished the ports (It uses bass reflex
speakers, so teh audio quilkity will only be limited by the amplifier I
can fit into it and the audio transmission.

I will likely have a case that can be carried on a strap that will carry
the reciever and power supply, and any equipment for controlling the
robot. I plan on having 2 way audio communication, 1 way video (robot
caries the camera), and command buttons on the remote and the robot,
using DTMF (remote DTMF will be transmitter over the audio channel).
I'll probably have a headset with a boom microphone. I'll have a manual
switch to activate or deactivate the speakers, so I don't need to unplug
the earphones so others can hear.

Since the display will be separate from the robotics control hardware, I
can also use it as a standard AV monitor. I'm considering gettin g a
small TV tuner so I can use it as a portable TV.

The case is a 10 cassette carry case. It has a handle and a locking deal
to keep it closed. I like that I can pop it open and show off my work! :)

I'll be writing up a report for it for school so I can get credit for it
as well, which is kinda cool too!

It uses the $139 Color NTSC LCD from All Electronics. If I had cash, I'd
buy more! Those things are NICE!!!

I also got my hands on a color VR helmet (though it's not stereoscopic).
It's got a tiny LCD in it, and if I can't get used to the thing as is,
I'll probably salvage the LCD in it. Nice as long as you don't care to
push text on screen. Nearly impossible unless it's large text. The All
advantage one is nice. It clearly shows the VCR menu text, with spaces
between characters and clear edges! If you need a color LCD, look in the
All Electronics catalog. It's nice! As an interesting added bonus, the
controls, in addition to brightness, color, and tint, also include a
switch that selects whether the image is normal or mirrored. It's fun
seeing how long it takes for people to notice everything is mirrored!
Hehe! :)
--


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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12681 Thursday, March 02, 2000 6:26 PM [alt-beam] Re: newbie Bruce Robinson sorry i had to resend this messgae but it looks simple. I feel i need to
help because i'm a newbie myself, and the veterans don't seem to like
newbies they had a debate on seperating veterans and newbies.

Jeremy


>William Cox wrote:
>>
>> Does any body have a schematic for a phototropic head
>> or ant that uses photoresistors instead of diodes?
>
>Here's one that has worked well for me. The photoresistors are the ones
>to the right of the 1 meg resistors.
>
>You'll need a slow oscillator of some sort to generate pulses for it ...
>easy enough to make one from a Schmitt inverter.
>
>In operation:
>
> - a pulse causes two parallel Nv's to go active simultaneously.
> Since the two outputs feed two sides of the head motor, the
> head won't move.
>
> - the photoresistors have a much lower resistance than the 1 meg
> resistors, so they shorten the usual Nv delays considerably. With
> different amounts of light striking the photoresistors, the Nv on
> the brighter side will time out more quickly and go inactive.
>
> - this will immediately start the head moving, until the slower Nv
> times out.
>
> - In order to make the motor run longer, the photoresistors are
> connected via diodes to the opposing Nv outputs. This means
> when the faster Nv times out, it effectively takes the
> photoresistor out of the slower Nv. This slows the Nv right
> down.
>
> - Each pulse from the oscillator moves the head a little.
>
> - The effect is to move the head in short bursts until the
> resistance in the photoresistors is balanced.
>
>Point the photoresistors slightly away from each other (i.e., not
>parallel) and shield them from overhead light. You will also want to
>have well matched phtotresistors. The circuit responds very nicely, but
>is highly sensitive to anything that unbalances the circuit.
>
>Note that you can't feed a common H-bridge with this circuit, as it will
>turn on both sides at once & fry the bridge. With a low current motor,
>you could use a 74HC245 to drive the head; or try one of Wilf's
>"smokeless" bridges on the Beam Heretics site (Rigter Archive). I
>believe Wilf also created a similar circuit to this one which used a
>single chip to provide some limited head driving capability.
>
>Enjoy,
>Bruce



Attachment: Head.GIF

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