Alt-BEAM Archive
Message #08554
To: beam@sgiblab.sgi.com
From: Bruce Robinson Bruce_Robinson@telus.net
Date: Wed, 22 Dec 1999 09:27:44 -0800
Subject: [alt-beam] Re: Keeping things simple...
Ben Hitchcock wrote:
>
> Here's a repost of a post I sent in February this year:
>
> I pulled apart an amiga mouse and tried to get the photodiodes to work.
> Here's what I found:
>
> The transmitter is coloured pink, has two leads, and
> operates above 0.5 mA.
>
> The receiver is clear, has three leads, and consumes
> about 5 mA at 5 volts. The receiver is pretty special:
> it appears as if there is a bit of logic inside it:
> It outputs a clear high/low signal depending on whether
> the transmitter is in range or not.
Hi, Ben.
I don't think I was even on the list back in Februrary!
I recently spent a frustrating week trying to get a similar device
functioning. I was hampered by the fact that the two elements were
sealed in plastic; the device was part of a salvaged mechanical device
-- all the connecting wires severed with a side cutter; and only four
leads coming out of the moulded plastic housing.
However, I eventually tracked down the part on the Web, and discovered
what that funny 3-lead receiver is: A Schmitt phototransistor! Kind of
obvious, AFTER you know what it is. It's actually a very neat little
device -- no signal conditioning needed.
The manufacturer (in my case) was Vishay Telefunken and I managed to dig
up some specs. The transmitter is an IR LED, with a rated output of 100
mA. I was able to drive it with only 8 mA, across a 3 mm gap. That
suggests a maximum spacing of 10 mm at full current, although that's a
lot of current for a small robot to pump out continuously.
Regards,
Bruce
8555 Wed, 22 Dec 1999 10:21:08 -0700 [alt-beam] Re: Head circuits beam@sgiblab.sgi.com Senior And using dennison's idea, paint the main bot white/cover with mirrory
stuff.
Phillip A. Ryals wrote:
>=20
> I know this makes it terribly complicated, but how about...
>=20
> We just had a post about taking the IR transmitter/detector from a mous=
e to use in
> obstacle/cliff avoidance.
>=20
> Why not use the same on these? Maybe a central bot that has a main lon=
g-range
> becon for the others to home in on from far away. Then once they get c=
lose
> enough, they would see the small IR source above a connector of some so=
rt. The
> rouge bot could then have a basic head circuit made of IR detectors so =
that it
> could center itself at the plug. But the head itself would definitely =
need to
> swivel and be non-guiding because the bots' locomotion would need to st=
ay in the
> same general direction.
>=20
> If one robot could walk up beside the other and do this though, you cou=
ld probably
> make it do some crazy stuff. Might be really hard to manage it all tho=
ugh.
>=20
> Thomas Pilgaard Nielsen wrote:
>=20
> > "Phillip A. Ryals" wrote:
> >
> > > Quite right Thomas!
> > >
> > > Maybe it's me, but I want my robot to do *something* else. It just=
seems
> > > like going toward the light has been done to the point of ironing o=
ut any
> > > wrinkles. Now maybe we should go on to more advanced behavior.
> >
> > I agree. Though there I find theres a beauty to the photovore by thin=
king of it
> > as autopoietic. It is completely selfcontained and self-sufficient. I=
t's only
> > purpose is to optimize it's conditions according to the environment i=
n order to
> > optimize it's conditions according to it's environment etc. etc.
> >
> > I find your suggestion very interesting though. One thing I found int=
eresting
> > were Tildens hexapods - the ones that vere able to join up. The idea =
of "cells"
> > that join up to a larger organism with emergent properties and behavi=
our seems
> > neat. Would it be possible to make up some mechanism that would join =
the
> > individuals - not just by linking them together by magnets - but to m=
ake them
> > share their individual capacity - sorta like a joining of brains or t=
he likes.
> >
> > Cheers and merry christmas
> >
> > Thomas
> >
> > > Even if it's just seeking out a different target...
> > >
> > > I'm thinking of a robot that is maybe attracted to a becon on anoth=
er bot.
> > > That way, it's always moving. Maybe one bot is attracted to the ot=
her, and
> > > the other is repelled? Anyway, the whole time one could be chasing=
the
> > > other, and the other is always running away. That seems like a nea=
t little
> > > project. But then put the light seeking solar cells on each one fo=
r power.
> > > Now they have even more to do.
> > >
> > > That seems like a lot more fun to watch than just an ordinary photo=
vore.
> > >
> > > Or am I alone?
> > >
> > > Phillip
> > >
> > > ----- Original Message -----
> > > From: Thomas Pilgaard Nielsen
> > > To:
> > > Sent: Saturday, December 18, 1999 7:35 PM
> > > Subject: Re: Head circuits
> > >
> > > Wasn't Phillips point to make a robot that would be able to do some=
thing
> > > !else!
> > > than walking towards the light? Isn't that what you are suggesting?
> > >
> > > Cheers + goodnight (it's 2:34 here in Denmark)
> > >
> > > - Thomas
> >
> > --
> > ---
> > "Stj=E5lne tusser skriver bedst."
> > Yvonne Miller
8556 Wed, 22 Dec 1999 14:05:19 -0600 [alt-beam] Variable Voltage Solar Cell "beam@sgiblab.sgi.com" Kelly Petriew Cruising the web and ran across the following:
http://solarhut.com/home/369panel.htm
Its a 3,4.5,6,9 volt selectable solar panel with alligator clips and a
recharging compartment for 2 AA batteries. 100ma for 3 & 4.5v and 50ma
for higher. Not only could you test your solar engines, but recharge
your batteries for your walker. Wicked price too. Almost worth buying
just to scavenge the panels, heheh.
I am in no way affiliated with the company, but am seriously considering
purchasing one of those units.
Please don't lash out at me, I'm new to the BEAM scene and this list.
Just thought I'd try to help out a bit..
I intend to have my first bot (a 2 motor, 4 legged walker) built by
Christmas so I can show off my new hobby to family (and try to get my
brother interested as well, heheh).
--
Kelly Petriew
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