Alt-BEAM Archive
Message #01975
To: beam beam@corp.sgi.com
From: Richard Piotter richfile@rconnect.com
Date: Thu, 01 Apr 1999 20:46:02 -0600
Subject: [alt-beam] Re: a simple challenge
That's what I want to do with Quadrapod. Basic BEAM controller that
interperets a simple remote input.
While I'm at it, is there a circuit that can determine if an input
matches a particular frequency? I need to decode a DTMF modulated
signal. To do this, I need to have the circuit represent 8 specific
tones (2 at a time, since the DTMF is made up of 2 tones mixed on each other).
I COULD buy a DTMF decoder, but I'd still like to know how to build the
decoder. I kinda like the challenge of discrete circuits over large
scale devices. It's fun! Hehe! BEAM fit's my hobby perfectly!
Bob Shannon wrote:
>
> Sean wrote:
> >
> > To say that a robot cannot do something without a CPU is simply
> >saying that one lacks the necessary knowledge to build a robot without
> >a CPU that performs the desired task. After all, all a CPU is composed
> >of is simple logic gates. The advantage a CPU has is that it can be
> >easily modified, and its function can be changed. BUT! Even the most >complicated computer program can be hard wired, that is, built out of
> >logic components, without a CPU. As long as there is no necessity to
> >load a different program, there is no necessity of a CPU.
>
> Its not quite this simple.
>
> CPU's were originally designed because it would take less electronics
> than a fully hardwaired machine designed to perform the same function
> (ballistic trajectory calculations originally).
>
> The CPU gets to use the same logic and registers over and over again,
> where the hardwired machine may need a larger number of physical
> registers.
>
> Very often the hardwired machine needs to alter its operation as part of
> its normal function. In these cases a CPU can easily be far more
> efficient (in terms of power and weight) than hard wired logic.
>
> In many cases a small CPU is the most minimal solution! Simply put, the
> CPU is the best choice for a BEAM robot with complex behavior.
>
> Look at Terry Newton's Picbot II, and with no more circuitry than a 2
> motor walker here is a robot thats head and shoulders above any BEAM
> robot in terms of behavioral complexity.
>
> I suspect that with some slight gear reduction and larger wheels, this
> class of solar robot will be far more efficient than even the 1381 based
> SE (which it really is, if you think about it!).
>
> The 16LF84 CPU chip Terry used can draw less current than a 74HC14 at
> slow speeds.
>
> And here's the best part:
>
> If we all started to use something like Picbot II, we could EXCHANGE
> behavioral sets! If a standard hyper-beam robot like Picbot II was sold
> as a kit of two, we each could have identical 'home-team' and a
> 'vistor's' team bots. We could compete in each others jurassic parks
> after sending a file by modem or internet.
>
> Then we would have some real evolution in stimuli-response based
> robotics!
>
> Lets get past this anti-CPU hype, its not contributing to BEAM
> evolution.
--
Richard Piotter
richfile@rconnect.com
The Richfiles Robotics & TI web page:
http://richfiles.calc.org
For the BEAM Robotics list:
BEAM Robotics Tek FAQ
http://people.ne.mediaone.net/bushbo/beam/FAQ.html
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