Subject:
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Re: Is Robotics Discovery Set good?
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Newsgroups:
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lugnet.robotics
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Date:
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Thu, 26 Oct 2000 03:50:19 GMT
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Original-From:
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Steve Baker <sjbaker1@airmail.net#Spamcake#>
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Reply-To:
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sjbaker1@airmail.[ihatespam]net
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Viewed:
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782 times
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> Bradley Dale wrote:
>
> > I got a catalog today from a science store in Toronto, and it has relativley
> > low priced Mindstorms. There are Droid Developers for $105.00, and Robotics
> > Discovery for $159.95. This is quite close to the American price, so I think
> > it is a better value than they would be elsewhere. Invention System 1.5 is
> > $299.00, like it always is.
RIS is still selling in the US for US$180 or so - RDS has dropped A LOT in price
and our local 'Fry's discount electronics warehouse has them at US$68.
Droid developers is hopeless - except perhaps as an add-on set once you have
one of the others...and even then, I'd buy a RDS set as an addon first.
> > I like the Robotics Discovery Set, and it says
> > that you can create over 3,000 different behaviours for the robots. Is that
> > true?
Well, I presume that 'advertised' figure for the Scout controller in the RDS set
comes from:
7 different ways to have it drive the motors (Forward, Zig-zag, Circle-left,
Circle-right, Loop A, Loop B, Loop AB).
4 ways to have the touch sensors affect that (Reverse motors, Avoid touch,
Wait for touch, Brake on touch)
5 ways to have the light sensor operate (Seek dark, seek light, Avoid light,
Wait for light, Brake if light)
3 different motor power settings
4 different sets of sound effects.
So 7*4*5*3*4 = 1680 ... I don't know where they get the other factor of two...maybe
because you could connect just one touch sensor or both...something hokey like
that...but you get the idea.
In practice, 99% of these combinations are useless/meaningless...in practice, the
scout has maybe a dozen 'interesting' pre-programmed behaviours...and it can be REALLY
frustrating when you can't quite get it to do the exact thing you want.
Also, the scout has only TWO motor outputs and TWO interchangable sensor inputs
(the third is permenantly assigned to the built-in light sensor) - it can't make
use of sensors other than touch sensors - so no rotation sensors for example.
The RCX (in the RIS set) has THREE motor outputs and THREE sensor inputs
that can be light sensors, touch, heat, rotation, etc.
Three motor outputs is almost a 'must' because you need two outputs to
make your robot able to move around (one to steer and one to drive - or
one to drive each of two wheels/tracks) - so if you want your robot to
do something "interesting" as well as just drive around, you NEED that
third output. (Actually, you could use a dozen output sometimes - but
that's another story).
> > I think a toy like that would keep me contantly amused for years. But
> > the TLC catalog says microscouts have only 7 programs. Can this be correct?
Probably - the Microscout is MUCH less capable than either the Scout or the RCX.
The bottom line is this:
* If you actually want to program your robots from your computer and do most
of the complicated and interesting things we talk about on this list, then
you need to start with an RIS set. That gets you the top-of-the-line
RCX brick and the Infrared tower that lets you program it from your computer.
This is a great set - it has enough parts to let you build a LOT of interesting
things - although the instructions that come with it will force you to think!
* The RDS is interesting only if your main interest is in building with Lego and
not with making *real* robots that behave as you want them to. I think you'd
lose interest in the Scout's "3000 behaviours" within a couple of days.
The instructions that come with RDS allow you to build a handful of amusing
things (A light seeking insect, an automated basketball hoop(!) and a burgler
alarm that can shoot a rubber-tipped dart when you turn the light on) - but
you rapidly discover that although you can make robots that *look* different,
your limited ability to control them makes this less interesting than you
might hope.
* The RDS set with its Scout controller (at US$68 at least) is a useful SECOND
set to buy IMHO. Once you have the tower from the RIS set, you can actually
send *SMALL* programs to the scout - making it behave more like a mini-RCX - but
you need the tower (and probably the software) and you don't get that with RDS.
The scout also has some quirky restrictions that can make it hard to control
complex robots using it (the inability to read rotation sensors is a particular
pain).
* One cool thing is that if you have both RCX and Scout, you can send instructions
to the scout from the RCX - this makes it useful as a way to get more motor
outputs and more sensors into more complex robots. With the RDS set being
*SO* cheap now, this is a very attractive proposition IMHO.
* The Microscout is pathetic - don't bother with the overpriced Starwars themed
sets unless you really want to build R2D2 or the ATAT and very little else.
Those are truly "toys".
> > think that this is what for Christmas. I will ask for this set anyway, since
> > it is bound to be more interactive than the Freight & Crane Railway train I
> > was previously wishing for (and no, nobody has bought the train yet). PS: I'm
> > 13 years old and don't have any previous experience with robotic programming.
Lego is a **GREAT** way to learn - and don't let anyone tell you that you aren't
old enough. My 9yr old has managed to have a LOT of fun programming our RCX.
The cool part is that you get this really simple 'visual programming environment'
in the RIS set that lets you drag and drop little chunks of 'behavior' to make
a program - it's *REALLY* easy and there is essentially no typing to do.
Once you've mastered that, you can progress to NQC (Not-Quite-C) which is a full
programming language - just like "real" computers use. This is not a great leap
from the visual programming environment - and NQC is a free download.
If you ever aspire to the status of a true computer geek - then you can progress
on to LegOS - which gets you about as deep into computing as any other kind of
programming that I can imagine...yet it's not that big a step from NQC.
If you can master even NQC, you won't be a long way from being able to write
programs for your PC, etc, etc.
> Brad, if you can, go for the RCX (RIS) It will be usable for MANY years to come as
> you grow.
That's good advice.
As an intelligent kid who wants to do something more than watch TV and use the
net for IRC, you can't beat the RIS set. You can have fun with RDS too - but it
won't keep you interested for long.
If you have to convince parents to buy the RIS, I'd tell them this:
Life of the Microscout sets: The time it takes to build R2D2 and the other
things on the box lid...a week maybe.
Life of the RDS/Scout set: Many weeks - a month or two tops.
Life of the RIS/RCX set: Well, there are adults on this list who are still
getting a LOT of educational value after a couple of years. If you
have an active mind, you may never lose interest in this set.
In terms of $$$ per hour of amusement, you can't beat the RIS.
--
Steve Baker HomeEmail: <sjbaker1@airmail.net>
WorkEmail: <sjbaker@link.com>
HomePage : http://web2.airmail.net/sjbaker1
Projects : http://plib.sourceforge.net
http://tuxaqfh.sourceforge.net
http://tuxkart.sourceforge.net
http://prettypoly.sourceforge.net
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Message is in Reply To:
 | | Re: Is Robotics Discovery Set good?
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| (...) Brad, if you can, go for the RCX (RIS) It will be usable for MANY years to come as you grow. I have all three units and I can tell you that the RCX (RIS) is the best. There was another message group that discussed all this in detail. (URL) the (...) (24 years ago, 25-Oct-00, to lugnet.robotics, lugnet.loc.ca.on)
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