Apr 30, 2009

Calibrating Motors

Techbrick.com's Marco emailed me the following:

As we all know, one the endearing qualities of LEGO robotics is its inherent imprecision.

As good as the NXT motors are (and other components), they are, at their core, basic DC motors with gears. All of our motors (about 20 of them) all work slightly differently in terms of acceleration, power, braking, etc.

Yet it is essential that your motors (particularly paired driving motors) be as close as possible in performance specs.

So how do you do this without torque gauges, tachometers, etc.? Leu Beach, one of our new mentors, along with our programmers, Jonathan, Doug, Nate, and Cole, came up with the most amazing, simple, calibration system ever.

It took us about 15 minutes to test all our motors. The resultant matched set vastly improved the robots directional consistency and performance.

Read to be amazed? Read on....


FLL 2009-2010 signup

I received an email from James T:

Just want to remind everyone that registration for the 2009 Smart Moves begins Monday May 4th at noon.

You can go to the site now and create your new user account before the May 4th date, so you are all set to get started once the registration is open.

There is a new site for team registration this year so be sure to check out the site and the new process so that your registration process goes smoothly.


Grab your passport...

(CAD Building Instructions created by Christopher Smith.)

Apr 27, 2009

More NXT books coming...

Sorry, no details, but I can tell you that more NXT-related books are coming. For many of us who write these books, however, there are always pluses and minuses.

I was reading through some reviews of the last book, One Kit Wonders, and the latest review caught my attention... and made me realize that when it comes to NXT books, you just can't win :)

Feedback on Idea Book (both in reviews and from emails and blog comments) was supportive, but there seemed to be a larger group of readers who felt that the book was heavy on theory and needed more robots - "less talk, more building" seemed to be the consensus.

So... One Kit Wonders got rid of the theory and focused on just robots and the programs to run them. The latest review was 4-stars and stated "This book shows you how to build and program 10 robots . . . that is pretty much it" - - - 10 robot BIs and PIs and "that is pretty much it."

All these comments beg the question: What does the NXT robot owner want in a book?

Any my response: Whatever it is, it cannot be satisfied with one book. (And according to Malcolm Gladwell in his book "Blink," the consumer really does NOT know what he/she wants most of the time anyway.)

Readers want color -well, color will either raise the price of the book (fewer sales and less incentive by publisher to do more) or reduce the page count (fewer robots, fewer sales, and less incentive by publisher to do more).

Readers want more robots - BIs take up a large portion of pages, reducing the number of pages for text/discussion/training.

Readers want more discussion/training - Screenshots of NXT-G software take up a large portion of pages, reducing the number of pages for robot BIs.

I enjoy writing books on NXT and I think many of the other blog contribs feel the same way... but it's very difficult to gauge what our readers want because NXT users are such a large and diverse group in both skills and interests.

True story: I had someone (an adult) come up to me about 6 months ago at a robotics gathering in Atlanta - this person told me "I didn't like Mayan Adventure because it was too short. You need to write the next one and have maybe 10 or more robots."

I bit my tongue because what I wanted to say was "Mayan took about 6 months to write, went through numerous tech reviews for accuracy, and 10 robots would have taken over a year to get done. Oh, and it was written for kids. You write the next one."

Okay, enough griping... my goal with this post was to share with our readers that more books are in the works, but also to inform that we can't make everyone happy. We'll do our best, though... and hopefully you'll like what we come up with...

Apr 24, 2009

FTC World Championships #2 - How the Game Works

I'm waiting on some videos to post more about the FTC World Championships and our robot, but in the meantime you can see a video our team put together of our experience at the competition here.

I also thought I'd post a description of this year's game so that readers can understand what's going on in the videos. You can click here to see an animation from FIRST that explains how the game works.

At a tournament, teams first participate in several qualifying matches. During each qualifying match, two randomly selected teams ally with each other against two other randomly selected teams. The two winning teams gain 2 qualifying points, while the two losing teams don't gain any. After the qualifying rounds, the team with the most qualifying points is ranked #1, and so on. But what happens if multiple teams have the same number of qualifying points? In this case, a somewhat-confusing tiebreaker is used. After each qualifying match, the four participating teams recieve the score of the losing alliance as ranking points. So if one alliance scored 130 points in a match and the other scored 95 points, all four teams in the match would recieve 95 ranking points, the score of the losing alliance. Then, if two teams have the same number of qualifying points, the team with the most ranking points takes precedence. For example, in Atlanta, Power Surge won all six of our qualifying matches, thus gaining the maximum number of qualifying points. However, there were three other teams who also won all their qualifying matches. But since we had the most ranking points, we were still ranked #1.

After the qualifying matches are over, a certain number of the top teams advance to the elimination rounds, where the winners are determined. At the World Championships this year, the top four teams in each division advanced. Each of these teams (called the alliance captains) pick two alliance partners to form a permanent alliance in the elimination rounds. The #1-ranked team picks an alliance partner first, then the #2-ranked team, and so on. Then they start over, with the #1-ranked team picking their second alliance partner and so on until there are four alliances composed of three teams each: the alliance captain and two teams they selected.

These alliances then compete with each other in a series of semifinals and finals. In each elimination match, alliances send two of their three teams to compete. In the semifinals, the #1-ranked team's alliance goes up against the #4-ranked team's alliance, and the #2-ranked team's alliance goes against the #3-ranked team's alliance. The two alliances which win at least 2/3 matches against their opponents advance to the finals, where they compete against each other. The alliance which wins 2/3 matches in the finals is the winner. At the World Championships, there were two divisions this year, each of which had their own elimination matches. So after the elimination rounds were completed in each division, the two winners of the divisions went up against each other for the overall finals.

Wow, long post... it's pretty simple, isn't it? :-)


Interesting flyer and website

This flyer was being handed out at the LEGO MINDSTORMS booth in Atlanta. It talks about the "SuperNXT", of which various rumors have been circulating around recently. It also links to this website: http://www.mindstormsprojects.com/

Interesting stuff...


Apr 22, 2009

FTC World Championships

Power Surge had a great time competing at the FTC World Championships this year. Congratulations to the teams on the winning alliance: the RoboRaiders, Longhorns, and Jr. Bomb Squad! My team was ranked #1 in our division after winning all of our qualifying rounds, and made the highest score in both divisions (222). In the elimination rounds, we made it to the finals in our division (Edison), but a strange problem hit our robot and kept us from winning them. I'll be making some posts later on with pictures and videos of the event and of our robot.


I want my iLEGO!

Okay, so I just finished a four day visit with various LEGO staff, MCPers, and other people of interest at WorldFest... and some of the conversations got me thinking. One discussion in particular caused me to immediately re-read "The Long Tail" by Wired magazine Editor-in-Chief, Chris Anderson. There's so much stuff in there, it's hard to know where to start, but it got me focused on the concept of micro-commerce. Years ago, the LEGO MINDSTORMS division had a well-known piece of paper hanging in an office that said "What Apple is to music, LEGO will be to robotics"... or something like that. What did they mean?

Some might say the obvious answer is iPod, but for me, the answer SHOULD be iTunes. Yes, the iPod is everywhere - in all colors, shapes, and storage capacities. It could be argued that we now have the NXT in white, gold, and black, but inside it's the same NXT. So let's look at iTunes. iTunes started out selling individual songs for 99 cents each. We no longer had to buy an entire CD with 15 or so songs, half or more of which we rarely listened to. (Has anyone else noticed that the music industry has changed to a One-Hit-Wonder model? The days of super bands is really over - we buy this song from Band 1, that song from Band 2, and on and on... I can't remember the last time I bought a full album.)

Anyway, let's try and fit the iTunes model to LEGO. It's not easy. Yes, we have the LEGO Factory where you can build your own designs, upload them, and others can select them and purchase the pieces needed to build their own. But the software is extremely limited - I'm held to a few small collections or groupings of similar parts and I can't stray. I'm not impressed.

"The Long Tail" says that we're niche consumers these days... and it's completely true. But not when it comes to LEGO. We are stuck, really, buying whatever pre-packaged models they choose to offer us. Many of them sell a ton, but LEGO appears to be missing out on The Long Tail of the market. Yes, we have Bricklink if we wish to purchase individual pieces, but there's some real issues with costs on that site... while many pieces are cheap and can be bought in bulk, other parts that might be considered "rare" are priced sky-high and out of reach of most consumers. We're talking about plastic here! Just like the diamond market, LEGO controls the flow of parts and this in turn affects pricing. I don't know what the difficulty would be for LEGO to make every variation of molded plastic it sells available for individual purchase - but this is the age of the Internet, folks... there's some talented programmers out there that could probably figure out how to create an online catalog of every item LEGO sells and a whiz-bang shopping cart system to boot. Maybe LEGO only sells 1 piece of Part#123456 a month, but if 100,000 people each buy 1 unique piece at a reasonable price, now LEGO is dipping into The Long Tail - more variety of parts sold in smaller quantities. As Chris says, a large number (the total # of parts LEGO makes) multipled by a small number (the number of people purchasing each part) is still a LARGE NUMBER!

Chris talks about Producers - about how the tools to create are democratized. Well, this doesn't exactly happen with LEGO because of intellectual property. You can't go make your own molds and sell your own LEGO-compatible parts - you'll have lawyers camped on your doorstep tomorrow morning. (But Producers do exist in another area of the LEGO world, especially when it comes to MINDSTORMS, and I'll address that in a separate post soon.) So, unless LEGO offers to make parts available for individual purchase, consumers will be held to purchasing big kits (Technic kits, for example) at big prices so they can have that one special part included in the package. Yes, LEGO is making money on the sale of that kit, but I'll bet you that they'd sell more of that ONE SPECIAL PART at a reasonable price than they will of the BIG KIT... and still make a nice profit. At least that's the argument in "The Long Tail" and I can't find a hole in the claim. My Calculus is rusty, but the area under the curve of The Long Tail is still a hefty volume (or profit) of sales compared to the "Hit" section that is basically all of LEGO's packaged kits.

The question, ultimately, is this: What do I want? (And by "I," I mean ME... the lone consumer.) I want to expand my ability to design cool robots by shopping online and purchasing those specialty items that I lack. I like Bricklink, but I'd really prefer to buy from LEGO - no offense, Bricklink sellers. I can buy 30 or 50 or 70 unique pieces from one place rather than 30 or 50 or 70 individual sellers... I have a place to ship a part back to if something is damaged and KNOW that I'll be taken care of... and I know I'm not being gouged with an unrealistic price. If LEGO monitors its sales, it'll know when something is priced too high and can immediately fix it and watch sales start to grow.

Chris has a new book coming out in July 2009 called "Free" - it's based on an excellent article he wrote for Wired magazine a while back. I won't even get started in this post to address how LEGO might take some of his concepts there and implement them - yes, another post for later... sorry.

NXT 2.0 Box

While at WorldFest, the 2.0 kit box was being shown around... eye catching colors and graphics. Our very own Laurens has his name and a robot he built using the kit's parts featured on the back of the box (a little hard to see in the photo, but in lower middle area of box).

The Betarex (is that the right name?) seems to be an improvement over the Alpharex... but the poor fellow had his new Color Sensor "borrowed" early in the event... fortunately LEGO brought a replacement and he was repaired.

Apr 21, 2009

WorldFest Update 2

Joe Meno (www.brickjournal.com) provided the following links with tons of photos... thanks, Joe!

FLL Opening Ceremony:

FLL Day 1:

FLL Day 2:

FLL Awards:


LEGO and LEGO Ed Booths

This year LEGO and LEGO Ed had booths side-by-side - this made it easier for anyone with questions to get a quick answer from the proper group. Here are a couple of pictures of the booths - MCPer and NXT Step blogger Chris Smith did a great impersonation of the new NXT 2.0 mascot.

Apr 20, 2009

WorldFest Update 1

I met an interesting team at WorldFest this year - you can read about them here.

They're the "first all-deaf team to place in a top slot at a FIRST Robotics Competition in Georgia."

How cool is that?!

Meeting and watching the team was great, but what I'm really wanting to do right now is to start learning sign language... I think I may add that to my To Do list for this year.

WorldFest 2009 Updates coming...

I'll be adding some various posts today and throughout the week - plenty of stuff happened and was discussed during the events, so I'm not quite sure where to start. I'll be posting some pictures, too.

I'll invite any of our readers who were attendees and who'd like to share some comments or pictures to email me and I'll try and get your feedback posted as well.

Apr 19, 2009

NXT Wheel: remote control for mobile robots

Remember the NXT Switchboard, the NXT-based remote control I posted some weeks ago about? It allows you to remotely control each motor of a NXT robot independently. However, it turned out that it's better suited for immobile robots as it's usually pretty difficult to actually steer a mobile robot when you need to control each of the driving motors on your own.
So I decided to create another remote control particularly aimed at such car-like mobile robots, called NXT Wheel; as a consequence, it has a large hand wheel and a speed throttle:

The response time is somewhat low, though...

Apr 18, 2009

Are there local Robotics events near you?

I live in Maine.  There is a Maine based non-profit that is pushing to teach Robotics to students.  It's a great way to get people interested in robotics (specifically using LEGO Mindstorms and VEX systems).

They organize and run the FLL competitions (usually two for the State of Maine).  They have other events, such as a Track Meet (a series of challenges for the NXT or RCX bots) and they also run robotics camps.  There are several of these camps every summer.  Each one is one week long, and they have beginner, intermediate and advanced classes.

You can read a bit more about Maine Robotics here, or check out the Maine Robotics website.

Are there local robotics groups where you live?

Apr 15, 2009

More information on Mindsensors devices

A while ago, I posted about new Mindsensors.com sensors: here and here.

Rob McGlade was one of the beta testers of the NXTHotShoe sensor, and used to create high speed images, as shown here. You can find more information and applications (such as a time lapse video) on his youtube profile

I have recently been working with the PFMate: a device, used to control up to four Power Function receivers (eight motors) from one NXT sensor port. I've used this sensor in a robot arm, as shown in this video.

Furthermore, Xander has made a movie of a line follower using the NXTLineleader. You can find it here.

Apr 12, 2009

World Festival 2009 - Atlanta, GA

If any of our readers are going to be in Atlanta, Georgia this next week for WorldFest, please try and come by the LEGO booth to say hello. A few of The NXT Step contributors will be there as well as a number of MCPers (MINDSTORMS Community Partners).

I know a lot of teams have emailed me (coaches and students) letting me know they'll be there - I'm looking forward to meeting all of you. See you next week.


Apr 11, 2009

Overview video on WeDo

Recently, I got a WeDo set and played around with it. One of the results that have been spinning off is this little video that provides some initial overview:

Apr 10, 2009

NXT on Sale

Blog reader Michael B. emailed me the news that Amazon.com has the NXT on sale... for $203.00. I'm not 100% certain this is a new price, but it does sound like a reduced price, so I'm posting just in case...

Here's the link - thanks, Michael!

Apr 9, 2009

Paint your easter eggs with the NXT

Easter is at hand, and in time MCP Mike Brandl from Austria has adapted his 2008's christmas bauble painter to use it for painting easter eggs:

At the bottom of the assiocated web page, you can find a LDraw file that can be used as building instructions as well as the archived NXT-G program (including the required MyBlocks and a small ReadMe for usage).

Go for it and show us your best easter eggs you have created with it!

Apr 8, 2009

Non-NXT, but still awesome: The Brick Artist™

Something for grazing in-between: I ran about the web site of this guy named Nathan Sawaya from New York who is creating tremendeous pieces of art solely from LEGO® bricks.


Apr 7, 2009

14º 04' N / 90º 09' W

Communicate with the NXT over a network using the standard BT protocol

I have just completed a program that makes it possible to communicate with the NXT over a network using the LEGO Bluetooth protocol. The idea is simply to have a server between a number of network clients and the NXT. This makes it possible to forward messages from TCP/IP to Bluetooth and vice versa. I have also updated my C++ communication library so that it supports network communication. This makes it easy to send commands to the server. But wait there is more... if you don't want to write your own program to communicate with the NXT over the internet you can download a network client that will allow you to set and read all four sensors as well as control the motors.

Please place a comment - maybe tell what kind of cool projects you want to build with these tools. Happy Easter


Apr 6, 2009

NXT Trailer Pull

I've had a few requests and questions about using the NXT to pull a lot of weight, so I decided to do a little study on trailer towing, using a single NXT set, which resulted in this NXT Trailer Pull project. I got it to pull about 45 lbs (20 kg), which is about 30 times the weight of the vehicle, and also over 20 lbs (9 kg) up a 10% slope.

To tow a lot of weight, you need three basic things:

1. Structural strength to support the load
2. High torque to the drive wheels
3. Traction

So I attemted to address all three of these, within the limits of a single NXT set. For strength, the trailer is built extremely strong, with all the load taken by beams in compression (no load on any of the pegs), and the axles are supported on both sides by the shortest spans possible to reduce bending. It is quite strong, you could probably stand on the thing, but I didn't try that...

For torque at the drive wheels, I used all 3 motors geared down 3:1 to a common axle, nothing real exotic here, and this turned out to be plenty to work with. You could obviously go more aggressive with the gearing here, but it was not the limiting factor in my tests.

Traction is the trickiest component of towing a lot of weight (on an unpowered trailer). As many of you probably already know, if you simply try to tow a lot of weight using something like a string from the vehicle to the trailer, the drive wheels will just slip on the surface since there is not enough weight over them to get any traction. On a real trailer, the rigid tongue is designed to transmit part of the load weight to the rear axle of the tow vehicle (10% is recommended, as I remember from my days towing a car carrier), which gives you the traction you need. To demonstrate this, this NXT project includes two different hitches, a flexible one and a rigid one, so you can experiment and see the effect of the weight transfer on the traction.

With this design, the limiting factor then becomes how much weight the rear axle on the tow vehicle can hold. Here, the tow vehicle axles are not supported on both sides, so they will eventually bend quite a bit, to the point where I was not comfortable trying more weight, although there was enough motor torque and strength in the trailer to handle it. With extra parts to add more support here, or more axles, or a different placement of the load (e.g. "fifth wheel" configuration) who knows how far you could go...

Here is a video of the project and some test runs:

Apr 5, 2009

Building instructions for Raven and NXT Switchboard

Finally, I've found the time to create building instructions for The Raven, my Black NXT model, and for the NXT Switchboard, a NXT remote control, both of which I posted about recently here, thus following a popular demand.

Apr 4, 2009

Que-boid, a cube-shaped NXT robot

Mark C from Ireland has published a neat video on a cube-shaped mobile NXT robot, called Que-boid:

Very nice!

Do not forget to visit Mark's web site which is a true blossom in the NXT web garden; a multitude of very interesting NXT (and other LEGO®) projects can be found there, alongside with detailed building instructions.

FIRST World Championship

The FIRST Championship event, held at the Georgia Dome in Atlanta, GA, is coming right up. The FRC Championships, FTC World Championships, and FLL World Festival will all be held there during April 16-18. You can find more information about the event on FIRST's website, here.

My FTC team, 2945 Power Surge, has been very busy for the past several weeks preparing for the FTC World Championships, and we're finishing up the final preparations on our robot, team shirts, pit banner, etc. We hope to see you there!


Apr 2, 2009

NXTLog Climate Connections Challenge!

Using the missions from this year's FLL challenge, Climate Connections, solve them and enter your robot in this NXTLog challenge.

Don't have the missions? Make up your own, and build a robot to complete them!

Full details: http://mindstorms.lego.com/nxtlog/ProjectDisplay.aspx?id=b1c98d61-dd7c-49bc-83c7-f77ac83bc062

Enjoy and good luck! Richard

Apr 1, 2009

More of Jim's Random Musings

I recently finished reading "Outliers" by Malcolm Gladwell. A very interesting book.

As a parent of a two year old boy, the book really grabbed my attention; if you're a parent of a child (or possibly considering having a child), this book will amaze you. I probably can't do the overall theme justice, but I'll try - the book basically asserts that much of our success (or failures) in life are not necessarily linked to just IQ but in our overall environment and the roadblocks or opportunities that life throws at us.

It's a huge concept to get your arms around. As I read the book, I remembered back to my freshman year of high school - I was one of 12 kids in a class size of 320+ that had a home computer - my dad purchased the brand new Apple Mac - yes, the VERY first model - and I was hooked. It's not that having the computer influenced my studies or what subjects I chose to study later in life, but just having that computer was a major positive influence in ways I probably can't even number.

Let's jump to today's world and talk about the NXT kit for a moment. This is cutting edge stuff. For under $300US, a child, a family, and even a class (or school) can have some of the very latest in robotics technology readily available. Whether a child "gets it" is not the question here - it's the access. Does your child have access to this technology?

We take for granted, I'm sure, that every child has access to a computer, but that's completely untrue. Some schools may have 2 or 3 computers for the entire school - how much actual hands-on time do we truly expect children at that school to get at the keyboard? Probably not much. And I'm fairly certain that not every kid in the USA (let alone other countries) has access to the NXT kit. I'm continually amazed at the parents and kids who tell me they just learned about MINDSTORMS - and this is a kit that's been around since 1998! Over 10 years and many parents and teachers are still unaware that this level of technology can be purchased at the local toy store and even at Amazon.com.

"Outliers" was an eye-opener for me - it made me realize how many opportunities I had in my early years that influenced my education, my hobbies, my skills, and my career. And it made me realize just how easy it is to stifle a child's success in school and life. I'm not speaking lightly here, either - after reading the book, I found myself very upset and down as I thought about all the kids out there in school who may hold the cure to cancer in their heads or the next breakthroughs in energy technology but, for lack of opportunity, may find themselves discouraged or even completely cut-off from reaching their true potential.

The book has some adult language, here and there, but nothing super offensive - it's mainly found in some interviews with key individuals who have found success or failure in life and can explain how they got where they are. Entertaining stories of the succcesses of Bill Gates, Steve Jobs, and others are better understood once you get a background of their childhood and see what opportunities they had - not much was denied these guys, as you'll read about if you pick up a copy of the book.

Now, not everyone agrees with all the assertions made in the book, and I'm doing some of my own digging to verify some things covered by the author, but it's definitely worth a look if you've got the time. For those of us adults (teachers, parents, and AFOLs) who look at the NXT as a hobby and a fun experience, this book may very well open your eyes to a new idea: Just as there were certain periods in time of explosive growth in the economy and technology areas, there were also those who encountered just the right mix of chance and luck and opportunitites and were able to do some incredible things. The NXT, a toy it may be, is opening the eyes of kids everywhere to learn and try new things. It's encouraging math and science but it's also encouraging non-measurable things such as self-confidence, an acceptance that it's okay to fail sometimes when a lesson is learned, and discovering that there's almost always a solution if you look hard enough, study, dig deep, and experiment.

I realize this post is a bit "out there" but unless you've read "Outliers" it's a bit hard to explain just how much of an impact that book may have on a parent or teacher who has the ability to influence one or more children. Teachers are probably already aware of many of the concepts in this book, but not all of us are teachers. Some of us are just coming around to understanding that when we limit the opportunities given to our kids, we're limiting the opportunities they'll have later in life.

There's no real answer and I'm not asking for one - do we put an NXT in every classroom? That's not feasible and even so, it's not the best solution. Programs such as the OLPC (One Laptop Per Child) are just starting to scratch the surface of changes that need to be made, here and abroad. I wonder what kind of impact ONPC (One NXT Per Child) might have if it were even remotely possible...
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