Vex or Mindstorms NXT

TMT:

The VEX has the following benifits:

   1) VEX has both Radio Control and Microcontroller control.
   2) VEX robots are held together with screws.  While it takes
      longer to build a VEX robot, they tend not to fall apart.
   3) The VEX microcontroller has 6 interrupts, 8 motor
      controls, and 16 I/O's as compared to the NXT's 3 motors
      and 4 sensors (up to 3 NXT bricks can be connected via
      BlueTooth.)
   4) Lot's of metal pieces.

The NXT has the following benifits:

   1) The Lego community is huge.
   2) The new motors have rotations sensors built in.
   3) Lot's of platic pieces.


While I do not have hands on experience with either the NXT
or the VEX, the VEX seems like it has a bit more going for it.
I would tend to steer the smaller crowd (< 10 years) towards
the NXT, and the older folks (10+ years) towards VEX.  I figure
anybody who is 10 years old should be starting to learn how
screws work.

Just my $.02,

-Wayne

Thanks for the response.

Anyone else? I would like to get more opinions before committing
dollars.

TMT

Too_Many_Tools wrote:

If there is any First LEGO League activity anywhere in the kids' area
(do a web search for this or ask at your school), then I'd recommend
going with the NXT, since that will give them a leg up on that
competition.  The FLL competition is a lot of fun and generates a lot of
comraderie, i.e., they'll be able to share their robot skills with their
friends rather than just tinkering away on their own.

For older kids (high school), of course, FIRST uses the Vex system now.  
So that's probably the best approach -- under high school, get NXT; in
high school, get VEX.

HTH,
- Joe

Thanks for the advice Joe....you make a good point.

ANYONE ELSE?

This is the most active robotics newsgroup around, isn't it? ;<)

Santa Claus needs some advice....if you were a kid, which would you
want in YOUR stocking and why?

Thanks for any advice.

TMT

Joe Strout wrote:

For some reason, you did not get as many responses
as you probably should have.


One of the more active and accurate.


If the kid in questions is less than 10, go for the NXT;
above 10 go for VEX.

-Wayne

Thanks again Wayne....again I appreciate the advice.

Being that the kids in question are 11 and 12 of age, I will go with
Vex.

I am a bit concerned with the lack of responses on this question.
Considering the time of the year, I certainly am not the only one
asking what robotics kit one might want to place under the tree for
Christmas morning. The lack of responses does not speak favorably of
the amateur robotics community in encouraging new participants in the
hobby. The more people interested in robotics, the more robotic variety
that will exist for all of us.

TMT

Wayne C. Gramlich wrote:

Well, I could have responded, but didn't because I would simply have said
the same things the other people already said.

But now that you have made me write I might as well try to say something
useful...

I own VEX hardware but have never played with the Lego stuff.  I was a big
fan of Lego as a kid, but that was decades before they had anything as neat
as the NXT stuff.  I built a Van de graph generator out of Lego's and a
coffee can and rubber bands for example.

The VEX is neat because it allows you to build an R/C robot without having
to do any programing.  It comes with a high quality 6 channel R/C
transmitter (real R/C quality, not cheap toy R/C quality).  The controller
will act as an RC receiver by default complete with a few different options
on how it maps R/C commands to wheels so you can build both 2 and 4 wheel
drive bots.  It also supports a few default switch behaviors such as
killing forward motion when you hit the front bump switch.

The connectors I believe are all non-standard so you can't plug and play
with non VEX servos unless you build your own cables, and the R/C
signalling I believe is also non standard (and not documented) so expanding
beyond VEX hardware is hard.

The VEX programming environment is minimal and a bit stupid.  It's a flow
charting paradigm which produces C code - which you can see - but not edit.
It's got one genetic flowchart block type which allows you to hand type one
line of custom code.  If you know C, this allows you to hack a little more,
but you still can't write subroutines.  It's god for very basic stuff like
programing a simple response to a bump switch but that's about it.  There's
an upgrade I think that you have to pay more for that gives you a version
that lets you write subroutines.  I've not played with that.  It looks like
the programming kit the vexlabs sells might be the upgraded version.  Radio
Shack programming kits are the old version that doesn't allow subroutines.

But, if you want to get serious, you can just buy a C compiler for it ..

   http://www.vexlabs.com/vex-robotics-downloads.shtml
   C-BOT-COMPILER  $49.99

and do anything the PIC chip is able to do.  But then you quickly get to a
level the typical kid isn't likely to want deal with unless they are a real
engineering type.  You have to master all the complexities of both C, and
the PIC micro controller chip.  The chip is a PIC18F8520 running at 40 Mhz
which is 10 MIPS and includes 32K bytes of flash program space and 2048
bytes of ram and 1024 bytes EEPROM for variable space.  You can download a
version of the default C code from vexlabs which makes it act as the R/C
controller and then just modify it.

There's a good number of connections from the micro controller (16 A/D
ports, 8 motor ports and 6 interrupt ports) so if you do get serious about
the programing there's a lot to work with for adding more servos or
sensors.

The starter kit comes with enough to build a basic bot, but you find you
want to buy more hardware quickly to do anything interesting beyond
building a basic R/C bot to drive around, and the hardware is pricey so it
can add up quickly.  I've probably spent close to $400 and that was buying
everything at RadioShack's 50% off price.  For example, it doesn't come
with batteries so you have to power it with with AAs - but they tell you
you should only use the nicads.  Buying the battery kit is very useful, but
that's another $50.  The extra hardware pack is useful (duplicate of all
the metal parts from the starter kit), but that's another $80 at full
price, etc.

Checking the radio shack web site, it looks like all they have left are
light sensors on line - everything else seems sold out.  But you can use
the store locator to find stores that still have it in stock - I see the
starter kit is still available in two stores in my area for example (DC).

www.vexlabs.com has everything including selling all the individual parts
so you can get anything you want but it's all at the full radio shack
retail price before they started the 50% off sale ($300 for the starter kit
for example instead of the $150 you can still get it from Radio Shack if
you can find them).

--
Curt Welch                                            http://CurtWelch.Com/
curt@kcwc.com                                        http://NewsReader.Com/

I don't know what you're talking about.  It seems to me that you've
gotten a lot of responses.  This IS Usenet, after all -- hardly anybody
uses it anymore, except for old die-hards like us.  :)

Best,
- Joe

Joe,

If you check I got responses from four people...and I DO appreciate
each and every response I got...thanks guys.

My point is that this IS Usenet which is read by many
people....including the comp.robotics.misc group...and four responses
on two of the most popular robotics systems commercially available to
the public is not overwhelming.

If Usenet is not the place to ask robotic questions then where? Note
that I did ask earlier where else to ask. And in the past I have asked
this very question whether Usenet was the proper place to ask robotics
questions and was assured that Usenet is the place to do it.

I have noted in the past that it seems like pulling teeth to get
robotic information from this group which makes the contributions of
those who DO contribute even more valuable.

And yes I check the archives before each and every question I have ever
posted.

I have seen other hobbies die off because the membership does not
encourage new comers to the interest. Robotics in particular is a
difficult hobby to pursue because it requires the knowledge of many
disciplines. If we want manufacturers to provide robotic components and
tools, they need to have a ready and knowledgable audience that is
willing to spend money...and membership that is ever renewing. This is
accomplished by encouraging the young among us which is what I am
trying to do....which is why I am asking the advice of the group as to
Vex versus NXT for the holiday shopping season.

Again guys, thanks for the advice that was given...by contributing you
have helped encourage a new generation of robotic experimenters.

TMT now proceeds to trip and fall off his soapbox <grin>

TMT


Joe Strout wrote:

I don't think you're aware of how you're coming across. By continuing to
ask for more input after getting several responses that pretty much
covered all the cogent bases, by asking for even more opinions you make
it appear as if you don't trust or believe the answers you already got.
That's how it looked to me anyway.

Besides, a multitude of responses is no indicator of community support.
Since you asked for a comparison, your question explicitly requires that
posters have experience with both systems, out of literally hundreds
that are available. Just how many people have experience with both,
especially considering NXT is new? I've never even SEEN one, let one
owned one to make a comparison. (Yeah, maybe I should get out more
often, but that's besides the point...)

-- Gordon

My two cents.  Go with the NXT.  Building is simple enough that you'll
have time for programming.  NXT is very new.  This is it's first
Christmas.  The in the box programming language, NXT-G, is easy enough
that a 4th grader can use it, complete enough that adults can work with
it.  Outside the box, various programming choices are almost complete
(C, java).

Of course I'm completely biased.  My kids grew up on the Lego RCX and
RoboLab.

They know what a subroutine is.

Doug

I agree go with the Nxt.

There are c and java compilers for the Nxt as well.
http://www-education.rec.ri.cmu.edu/robotc/

Another option is botball  www.botball.org
Same bot as used in the first contests.
Uses a gameboy as the brain(with addition of an addon card)
Also lego based.
http://www.botball.org/educational-resources/web_course.php

All of the systems dicussed in this thread can be used by people of all ages
and at
all levels.

That said lego would be easier to use for those with no programming
experiance.
I've "played" with a wide range of bots and embedded systems and find lego
the most fun
and the most flexible .

To see whats possible with lego
http://mindstorms.lego.com/
http://mindstorms.lego.com/NXTLOG/default.aspx
http://mindstorms.lego.com/NXTLOG/news.aspx
http://www.norgesgade14.dk/legoSider/mindstorm_en.html


Can also program the Nxt controller using web services from the microsoft
robotics studio
in c++, c# or vb.net http://msdn.microsoft.com/robotics/


Alex

IF you are on a budget, the Mindstorms sets can be found on eBay or
elsewhere for around USD$100. There are HEAPS of books and resources for
Mindstorms on the web, and as well as having a programming toolset based on
icons which is good for kids, there are free third-party programming tools
including C/derivatives, Java, and Visual Basic.

There are also heaps of resources available showing you how to make your own
'home brew' sensors - a great way to learn about electronics.

And the Technics parts go well with Mindstorms, especially like cool
pneumatics kits!

The Lego FIRST robotics groups/competions are big in the USA I believe.

The NXT set looks tempting...

Cheers

|- ]

Dale ( I'm back.........)

[snip]


Gordon:

By the way, I posted a response to TMT's question without having
hands on experience with either system and I stated my lack of
experience in the post.  An informed response is all that he
needed.

Realistically, if TMT had asked "What is the best introductory
robotics system for children for this Christmas?", it would
have narrowed down to the VEX vs. NXT systems pretty quickly.

Anyhow, back to robotics before I take some time out to
participting in national over eating day.

Enjoy,

-Wayne

Possibly, through an alternative answer is "none." Turns out the
children in question are 11 and 12, and without knowing anything more
about them, or whether there will be an older sibling, parent, or
teacher to promote use of the kit, there is a good possibility a Vex or
NXT or anything else will become just another expensive closet stuffer.
Kids are all different, of course, but this is an age group when Guitar
Hero is a lot more interesting and fun than messing around with a robot.

My advice, were I to give it, would be this: get the kit that interests
the parent. For this age of kids, you buy  for the adult who will in
turn engender the kids' interest. If there are no adults or older
siblings in the house that will take up the interest in a robot building
set, go for the iPod or something.

-- Gordon

On Wed, 22 Nov 2006 17:57:20 -0800, Gordon McComb


   I try to "get out more often", and now that you prompt me, I recall
seeing the NXT demonstrated a few months ago, and what I saw may help
the OP make a decision.
   A "rep" from Lego (I forget her name, I could ask if you really
want to know) came to the Atlanta Hobby Robot Club to demonstrate the
then brand-new NXT. Her usual target audience is teachers (ISTR she
works for a separate educational distribution system for NXT that has
its own educational pricing for schools), but she held her own with
this room full of amateur roboticists of all ages. After she
demonstrated many of the abilities - sensors, drive motor control,
'block' visual programming on a PC and such - someone asked her to do
his "standard test", to program it to go in a circle. She went to one
of the blocks, set the drive motor control so one turns faster than
the other, had to go through the program download procedure a few
times before she remembered everything else to do (something about
activating something else so it would run), and the NXT bot was on the
floor going in a circle in less than five minutes after the request.
Not bad - the audience applauded.

   I don't know if the VEX has a graphical programming system, but as
others said a C compiler is available, and from what I've seen of it I
can second all the VEX-vs.-NXT statements.

   The next monthly AHRC meeting is tomorrow at 10 AM in north metro
Atlanta, and there's no telling who or what will show up. ;-)

http://botlanta.org/  

or just put robot club in Google.com and click "I feel lucky" :-)

I have both systems.

Both are well designed, and both are great kits for kids.  For non
programming, I'd recommend the VEX.  For beginning programming, I'd
recommend the NXT.  For more advanced programming, either is good.

VEX:
  - Has the remote control, so it actually appeals more to younger kids
since they don't need to do any programming.  The remote control even
allows for a few extra motors (6 channels), and has some limit switch
behavior built in for cranes etc.
  - The programming environment is good - graphical, but shows the C
code next to it, so you see both views.
  - Note that the programming does not allow for subroutines - you need
to pay to upgrade it ($50, I think).
  - Radio Shack will eventually sell out the 1/2 price stuff, and after
that, you will be paying full price online for parts etc.
  - They have curiously not opened up the protocol, so adoption in the
hacking robotics community may be limited.  Also, the programming
environment was outsourced, so it may be stagnating.

NXT (vs Mindstorms):
  - Still has only 3 motor ports, and only one more input (4 total).
but that does help a lot, and one of the input ports may be expandable
in the future.
  - Graphical development enviroment is much more sophisticated than
the Mindstorms was.
  - Lego has really opened up the protocols, so there should be a lot
of hacking and alternate dev environments. (see
http://www.roborealm.com  for adding vision with very little
programming)
  - The bluetooth allows for control by phone etc.
  - The parts are fairly arcane technics, and though you can use any
bricks with them, the design of the motors etc., are so non-block
oriented, that connecting them all togteher takes some serious
thinking.  Really not well suited to young kids IMHO.

- CFS

(check out www.teletoyland.com - allows you to control robots from the
web)

Too_Many_Tools wrote:

great questions! great answers! I am in the exact same situation and I
think I am going with the NXT for ease of programming and building with
ability to expand,  as well as, using existing LEGO parts.