Jun 29, 2007

This weekend: Fana' Briques 2007

Hi there,

for all of you who are located around the Alsace (France), the weekend next ensuing provides a particular dainty: in Rosheim the Fana'Briques 2007 event will take place on Saturday and Sunday. Exhibitors from France, Germany and Belgium will show their stuff on the theme LEGO locomotion. There will be a GBC, trains, walkers, a track with remote-controlled LEGO race cars, ...
The particular highlight will be the building of a life-sized Bugatti T35 classic completely with LEGO bricks.

Go there!

The address is
Halles au Marché (à côté de la Mairie)
Alsace, France

NXT Coyote

Menno Gorter, or ‘the walker Dutchman’, has created another wonderful NXT walker.
If you want to see it in action, you will need to come to LegoWorld 2007 (In Holland). Menno never shoots videos of his robots.
Check it out here:

The Mayan Adventure Parts Pack

For those of you who want to build the robots in Jim's book The Mayan Adventure but only have an Education NXT Kit, keep an eye on LEGO Education's website. Apparently they're going to be selling a "Mayan Adventure Parts Pack" which will include all the extra pieces needed to build the robots in The Mayan Adventure with just the Education NXT Kit. It's expected to sell for only $7.00 plus shipping.

Even for those of you who already have the neccessary pieces, this pack may be useful in other ways. Many people have noted how useful Hassenpins are and how hard they are to get - these things are selling for $5.00 a piece on Bricklink! In this Mayan Adventure Parts Pack, however, quite a few hassenpins are supposed to be included (the source thought it might've been six, but isn't sure). So this might turn out to be a good way to simply get more hassenpins if you really need them - 7 bucks isn't a bad deal.



Robert sent over news about his new robot, LHEX. Check out the video below.

From Robert: "There are no operational sensors other than the encoders, but work is in progress. The bot has tilt and compass from mindsensors that will direct and help the bot. The idea is that this bot will learn how to 'best' walk using acceleration & tilt readings. The server master was a challenge (comms speed wise) but after many hours I managed to get both sides talking at the speed i needed (30ms). Programing is being done in labview with NXT toolkit You'll notice it is based on RHEX."

New Contributor!

Hi! This is my first post as a contributor of the NXT STEP blog.

I have had Mindstorms sets for about one and a half years now. My first was a RIS 2.0 kit. I liked Mindstorms so much that I bought another second handed RIS1.5 kit. And in January this year, I couldn’t resist buying the NXT set…

The robots I have built with these kits can be found here. Also, together with the people from the official Lego message boards, I launched a website featuring building instructions for NXT robots.

As some of you may have noticed, I am fascinated by LEGO brick sorting robots. I have built three of them so far. As you are reading this, number four is under construction…
The first and second used the RCX, the third was made of the NXT kit. The fourth will use both NXT and RCX.

This machine should sort 10 kinds of bricks. (5 colours and 2 sizes) To ‘see colour’, it uses a photocell and the LEGO lamp. This way the NXT is able to see the difference between black, gray, white, red, yellow, green and blue. This is impossible for the NXT light sensor.

When the folder is public, you can find some pictures via my Brickshelf.

I hope to provide some useful posts to this blog!

Jun 28, 2007

Happy Birthday, nxtasy.org

NXTasy started on June 28, 2006. With so few blogs dedicated to the LEGO MINDSTORMS NXT, we're glad to see that nxtasy.org has survived and continues to provide regularly updated content. Congratulations on your first year, NXTAsy.

Power Functions Details Available

As promised by Philo, the PF motor specifications are now made available. They can be found in BrickJournal 8. A total of 5 pages are dedicated to the new PF system. Thank you Philo, Didier Enjary, & BrickJournal.

UPDATE: Power Function sets are now available! Here are the set numbers to look up at LEGO.com: 4957 (the "Ferris Wheel") and 4958 (the "Monster Dino").

NECC 2007 notes

I was able to attend the NECC 2007 on Monday and Tuesday (June 25-26) and visit with many of the LEGO Ed representatives there. They had a very nice booth area setup and were demonstrating many robots, including Brian Davis' LNE and some Tribots using the new HiTechnic sensors. HiTechnic also had a representative, Steve, who was available on Monday to answer questions and show off some of their products.

One of the highlights of my visit there occurred on Tuesday. The LEGO Ed rep for Texas, Betty, knowing I was going to be at the conference, arranged to have a video conference using one of the NECC vendor's real-time video conferencing systems, setup right there in the showroom. I was told 4-6 teachers would be there and it would be a Q&A session about the Mayan Adventure book... when the video popped up, I was looking about around 30-40 teachers in Temple, Texas. We had a nice discussion for about 20-25 minutes before I had to run. (This technology is really opening doors and plans are being made to have more of these distance-discussions.)

This conference focused on technology and math/science services and products available to the education field and I was amazed at the 500+ vendors there with all kinds of things to show off... looking forward to next year.

Jun 27, 2007

Website with Building Instructions!

Many of you have been looking for robots with instructions that can be built with one NXT kit. Brought to you by the members of the Official Mindstorms Fourm, a website of 5 GREAT robots has been set up, which four of the robots can be built with one NXT kit including a grayscale scanner! This website features a difficulty status, and NXT-G programs, can be found at http://www.freewebs.com/legorobots/

We hope to see more great models soon!


The Amazing Mr. Woo and His Astonishing Robots

Here's a British news report of an untrained peasant farmer who builds working robots. The robots get more fantastic as the video proceeds, especially when you consider that he builds these things from junk that people throw away. With formal training, this guy would be running Carnegie-Mellon.

He burned his house down while building robots. His wife thought of leaving him because of his obsession with robots. This guy needs an NXT.

Jun 26, 2007

Help Us Create an NXT CAD Dictionary

If we're going to create a body of knowledge about NXT CAD software, we need some clear and accurate definitions of terms used. If you have some of that knowledge, please go to our CAD forum and share the wealth. Here's a link to the specific thread:NXT CAD Definitions

NXT "Rope-Walking" Monkey

Jun 25, 2007

Crimp tool now available from Mindsensors

There is now a crimp tool available from Mindsensors. So you can buy the NXT jacks, and crimp your own cables (there are many materials available that make good cables).

They cost a bit more than regular crimpers, but hey... they aren't regular crimpers. These are for the NXT jacks! :)

Curses to Motocube.com for bringing these to my attentention... now I have to go buy some.

Block Robotics Learning

Here's the most comprehensive, year-round set of robotics courses for kids that I have ever seen. (Click on the above graphic to see the detailed schedule of courses).

The center is located in Windsor, Ontario Canada. Their web site is here.

NXT Gramophone

This one is not high-fidelity, but it gets a "10" for style points alone. See if you can name the song that the gramophone is playing.

NXT Slot Machine

Amazing construction, both inside and outside.

NXT Quantum Computing

A 14 year old student uses the LEGO NXT to demonstrate her research in programing matrices, quantum computing and quantum Braitenberg Vehicles:

Link Here

Brazilian Robot Fans

I received an email recently from Marcello Campos who lives in Niterói, Brazil. Some excerpts from his email:

"We have meetings every other Saturday, and I try to teach the kids a little bit about robotics, computers, network, team work, etc. We meet only every other Saturday, and the kids need time to play, explore, and develop their programming skills.

In the picture, from left to right are: Marcello, Gabriel, Pedro (my son), and Lucas. Or, as we call ourselvesduring our sessions, Mr. M, Mr. G, Mr. P, and Mr. L."

Marcello and team: We LOVE to hear from teams in and outside the USA, so thank you for emailing the pictures and keep us informed about your projects.

Sample Page from Idea Book - whatsit


We must both be extremely clumsy. I spilled motor oil all over my sample page and the scanned image doesn't look that great... but I'm sure readers will still be able to make out the details... they're a smart bunch!


In Memory of...

A special request has been submitted for the LEGO community and I'm including a link here to read more.


Jun 24, 2007

Sample Page from Idea Book - ScanBot

On the left is a section of the building instructions for ScanBot, the robot I contributed to the LEGO MINDSTORMS NXT Idea Book.

As you might deduce from the name, ScanBot scans black-and-white images, and you can build and program it completely from the contents of one Retail NXT base set #8527 (along with a computer that can run NXT-G, of course).


Jun 23, 2007

CAD rendering discussion

Fay Rhodes is one of a small group inside the blog contributors responsible for rendering the CAD drawings for our soon-to-be-released book. While there are many options available, Fay has started a discussion over in our Forum section by providing readers with her own steps for rendering drawings for our book.

Have something to contribute to the discussion? Tips? Alternative solutions? Head over there and add to the conversation. We're hoping to increase the body of knowledge available on CAD and building instructions for NXT and asking our readers to help contribute.

Sample Page from Idea Book - A Bot Chapter

I like games… Do You?

Here is yet another sample preview page from - The Lego Mindstorms NXT Idea Book: Design, Invent, and Build.

Unfortunately, I splattered paint all over my PDF file when I was mixing the new color for my budget space rocket. Silly Me. I’ll have to remember to keep my PC away from the shop. I apologize for the mess but this is all I can offer at this time.

So, what can you figure out from reading the full-sized image?

The first person to figure out the subject of the chapter AND the function of the bot wins a wonderful opportunity to be the test pilot on the maiden voyage of my rocket when I complete construction. The keenest investigators will carefully examine all of the available evidence for any clues. Be careful! Each person is limited to 1 guess. However, if a correct answer is not posted by Monday morning I will throw in a hint and allow each person one additional guess.

Everyone is welcome to talk about it... But try not to give away any answers before you post 'em yourself!

Have fun! (splatter)


Jun 22, 2007

CLARAty software for robots

This doesn't appear to be compatible with NXT, but I can't say that for certain... what did strike my interest was some text that appeared on the website:

CLARAty is a framework that promotes reusable robotic software. It was designed to support heterogeneous robotic platforms and integrate advanced robotic capabilities from multiple institutions. Consequently, its design had to be portable, modular, flexible and extendable.

Sounds like a nice solution that should be made available for NXT, huh?

Jun 21, 2007

Octopus Enthralled with LEGO DUPLOS

Way off-topic, but fun nonetheless.

Video and details here.

IRSeeker is available now...

HiTechnic will begin shipping the IRSeeker sensor on Friday, June 22nd. More information on the sensor can be found here.

The sensor will be very useful for teams wanting to develop robots to participate in Robocup tournaments.

The sensor is compatible with NXT-G (firmware version 1.3), RobotC, and NXC. The sensor provides feedback in the form of a number between 1 and 9, indicating direction of a detected IR signal.

Jun 20, 2007

Marty Video Submission from 4th Grader

Earlier in the Spring, The NXT Step conducted a small beta test of one of the robots showcased in The Lego Mindstorms NXT Idea Book due out this August. The following video is a submission from Jacob, a 4th grader from Ashburn,VA who built Marty the Performance Art Robot and successfully got it to render a pentagon.

More videos from the book can be found in the video section of this blog.


BrickWorld 2007

Just 2 days left to register for BrickWorld 2007. Held in Chicago, Illinois, June 21-24.

From the site: "BrickJournal™, BrickStructures™, Team Hassenplug, Team Possible, Team B-squared and Fun Time Technologies have joined forces and are pleased to announce Brickworld'07 to be held in Chicago. Brickworld™ is a chance to showcase your creations right here in the Central Midwest.

Brickworld'07 will be held from June 21st - 24th 2007. We are excited to bring this show to the public during a time of year when school is out and sunshine & good weather are in.

The floor organization of BrickWorld™ will be designed to accommodate large collaborative displays, such as the Great Ball Contraption, Moon Base, Castle and Train Layout, in the center of smaller, individual displays where each AFOL has their own creations on their own table(s). Of course, there will be certain displays that don't even need a table."

NECC 2007

The 28th National Educational Computing Conference is being held June 24-27 in Atlanta, Georgia. LEGO Education representatives will be there.

From the site: "Join more than 18,000 teachers, technology coordinators, library media specialists, teacher educators, administrators, policy makers, industry representatives, and students from all over the world who'll gather June 24–27 at the Georgia World Congress Center in the heart of Downtown Atlanta.

Our purpose? To help shape the future of education. How? By bringing together the best Ed Tech has to offer. NECC 2007 boasts more than 700 presentations in a variety of program formats that:

* highlight promising practices for leadership and school transformation
* showcase the impact of 21st-century learning environments and virtual schools
* demonstrate the impact of technology on student achievement and school improvement
* emphasize the ethics and equity issues involved in all these topics

This year we're especially focused on technology's role in developing 21st-century learners. What's our collective 2020 vision? How do we carry that vision forward into reality? Can we develop an intentional course toward that better future?

Greater opportunities for all 21st-century learners—let's keep our eyes on that prize as we explore educational horizons and discover together a better future."

NIWeek 2007

If you're going to be in or near Austin, Texas in early August, NIWeek might be of interest to you. The annual gathering of companies and products related to or doing business with National Instruments, including LEGO, will be demonstrating all kinds of new software, devices, etc.

From the site: "Join engineers, scientists, educators, and exhibitors from all over the world. NIWeek 2007 features three full days of interactive technical sessions, exhibitions, and workshops on the latest developments for automation, manufacturing, design, and test."

You can get more information here - LEGO and some of its reps are scheduled to be there along with some MUP/MDP/MCP members. More information as I can get it.

Jun 19, 2007

"Advanced NXT: The da Vinci Inventions Book": A Brief Review

This may be Matthias Paul Scholz's magnum opus, a book that combines history, art and NXT technology.

The heart of the book is building and programming instructions for five of da Vinci's contraptions: the armored car, the catapult, the revolving bridge, the aerial screw and the flying machine. Matthias provides five ways to program each of his five NXT models, using NXT-G, RobotC, NXC, pbLua and leJOS NXJ.

In addition, Matthias provides a detailed installation and configuration guide for each of the aforementioned programs. In my opinion, this guide alone is worth the price of the book.

Matthias provides a wealth of other material, including the historical background behind da Vinci's creations, as well as ideas for building other "NXT" da Vinci inventions.

A prediction: Matthias' NXT catapult will be standard equipment for office cubicles around the world.

Jun 18, 2007

New Book - July release


* 26 chapters + 1 Appendix
* Covers all the blocks that come with the retail/education software
* My Block coverage
* Chapter dedicated to data hubs and data plugs/wiring
* Introduces concept of pseudo code early and uses it throughout the book
* All blocks used in sample programs to demonstrate concepts

I originally wrote this as a tutorial for Atlanta-area teachers but it turned into a full-fledged book - 40 pages became 200. I'll post some chapter excerpts for download as soon as I receive them from my publisher. Table of Contents is included here as an image.

NOTE: This book is completely different in structure and style than my "Mayan Adventure" book; I still use an informal writing style, but this book does not include a fictional storyline to break up book sections. Chapters are short and suitable for short classroom schedules. All chapters cover one NXT-G block with the exception of two chapters that cover 2 blocks each.

Jun 17, 2007

Voice control for the NXT


The German company CLT Sprachtechnologie GmbH offers Dialog OS, a product for controlling technical devices by voice. The interesting thing here for the NXT-Community is the in-built support for LEGO MINDSTORMS NXT. Next to voice recognition, i.e. control of the NXT by words spoken by the user, there's also speech output on the NXT "in supreme quality" (as CLT states) .

Sounds interesting - have a look.

Jun 15, 2007

Sad News: Eric Brok has passed away

Today I was left in total sadness, hearing the sad news that the AFOL Eric Brok of the Netherlands, the designer of the new 10190 LEGO set, has passed away.

According to his wife Seby, Eric passed away peacefully on Monday 11th of June in the morning at 1 o’clock, after 1.5 years of fighting the cancer

Eric was one of the first persons in the Netherlands that actually showed the power of the LEGO MINDSTORMS set, released back in 1998. He was a remarkable personality, always building impressive models and proudly showing the new tricks. We used many of his
examples, in our own models.

I’m sure that the results of his participation in the LEGO community will be alive for a really long time.

For now my prayers and thoughts will go to Eric's family and close friends.

Farewell, Eric.

Help me light a fire...

I received an email from LEGO about the WISH LIST that was put together with the help of our blog readers back in March/April 2007. Well, LEGO has informed me of two pieces of information and I need your help with one of them:

1. LEGO is using the WISH LIST as a source for a potential future product... HINT HINT


2. LEGO told me it would be sending me notes/comments on the WISH LIST items shortly.

So, I need your help. Post some comments and let LEGO know that you're as anxious as I am to see their comments on the items we submitted. Some friendly pressure from our readers might help light a little fire...

(Keep it clean, polite, and short... this is just a friendly little 'poke' to see if we can get a response from them...)

Sample Page from Idea Book - Debug chapter

Our Idea Book doesn't contain just building and programming instructions for robots. We've also tossed in about 8+ chapters (I call them "theory" chapters - you can call them what you like) that cover various topics related to NXT robotics.

In addition to contributing a robot to the book, I've also written an introductory chapter on debugging programs. I introduce various methods that can be used in a pesky NXT-G program to help you track down bugs and fix issues. I provide sample programs that demonstrate how to use blocks such as the Sound block and Wait block (and a few others) with your debugging efforts.

Another sample page of our upcoming book

So here's another sample page of our upcoming The LEGO MINDSTORMS NXT Idea Book to water your mouths. ;-)

It's from the chapter that introduces the building and programming of a fully working slot machine.

Note that the book contains very detailed building instructions for each robot. In the case of the slot machine, it's more than 100 steps!
You will need not only two NXT bricks for this robot and five motors, but will also learn a lot from the programming instructions in terms of inter-brick communication.

Got interested?

LEGO MINDSTORMS NXT Software on Vista?

Every now and then, I get questions on the support for the LEGO MINDSTORMS NXT Software on Microsoft's Windows Vista operating system or reports on problems with connecting to the brick (even with an USB cable). As far as I know, the present version is only supported on Windows XP and Mac OSX (and not on Linux, which is a shame!).
What are your experiences here? Does it work for you on Windows Vista?

Jun 14, 2007

Our book - available in three weeks hence?

Have a look at Barnes & Noble: they list the book written by the contributors of The NXT STEP already, and it says to be available at 7th of July!
It's the first public appearance of the final cover also, I guess.
How do you like it?

Jun 13, 2007

Request for Programming Samples

I've enjoyed some of the last week's posts containing questions from readers regarding programming. Reading Brian and David and others' comments about other ways to handle things is a great way to learn... as Brian stated "There is no 'correct' answer."

I'd like to invite teachers/coaches/parents/students to submit their programming questions - either by email or (preferably) on our forum. We can't promise to provide working programs for every question, but some of us may pick one or 2 of our favorite questions and try and give you a programming example (and then let others provide options).

Book Review - Getting Started in Electronics

I try to keep 90% of my posts on the topic of NXT, so I hope you'll forgive me for getting slightly off topic here. MAKE magazine had a great review of this little workbook and I bought a copy. If you are a parent or teacher with a child or student who is expressing an interest in electronics, THIS is the book you need to check out.

It's written in the format of a lab book (the text looks like hand-written notes) and is VERY easy to read and understand. I wish I had found this book years ago when I was a student. It's got 100+ projects in it that are fairly easy to build using common electronics components found at most Radio Shack or similar-type stores.

I've read reviews in other places of books by Forrest M. Mims III and am very impressed with his style of writing and I can see why students are a prime target for this book.

While it isn't a true NXT book, any student interested in furthering his or her studies with robotics is going to have to invest some time in learning more about electronics - this book will jump-start you in that direction.
This 128 page book is $20US and can be ordered here.

Jun 12, 2007

Bridge-Building NXT

This NXT lays down a bridge, drives over it, retrieves the bridge and then lays it down again.

(Courtesy of nxtasy.org)

Programming Question from our Forum

The following question was posted to our forums by Itry:

"Hi. I'm new to NXT, and trying to figure out the basics of programming. I need a light sensor to detect change in ambient light levels, and if above a certain range to activate rotation of a motor in the forward direction 4 turns & stop, and if below a certain range to activate rotation of the same motor in the reverse direction 4 turns and stop. The motor needs to complete its assigned 4 rotations before being allowed to reverse. The program needs to run continuously, forever, so that once the light level changes beyond the threshold in either direction, the motor will react. HELP?"

Well, here's a screen capture of my solution. My comments in the image should be sufficient to comprehend the program. Maybe other readers can offer up their own ideas.

Jun 11, 2007

Restoring Firmware Files for NXT-G

"Gary" has asked how he can restore system files on his NXT brick if they're inadvertently deleted. Here's how:
1) Open up your NXT-G software and connect your brick to your computer. Make sure that you're connected to the internet.
2) Go up to the "Tools" menu and drag down to "Update Firmware".
3) In the new window that pops up, click "download".
4) After a few seconds, you'll hear a multi-toned sound. That means that all of your original system files are now back on your brick.

Jun 10, 2007

LPub Reconciliation

Since I reported on this blog that LPub has not worked on my new Windows computer, it's only fair to report that I tried it again today and it now works! (Thank you to Kevin Clague, God, or whoever is responsible.) Version 3 Alpha, however, still will not allow me to set a minimum distance. (My pins appear to be the size of watermelons---or larger.) I also ran some models in ldglite, and Philo is correct---it does render faster, albeit with a different appearance than POV-Ray/Mega-POV. Publishers may not accept that quality, but it's certainly acceptable for most purposes. (This test dummy was rendered in ldglite.)

NBC Beta 30 Released

John Hansen released another update to NBC/NXC, Beta 30, on his website.


NXT Trashbots

Some very creative,trash-collecting robots, using NXT components housed in artistic casings.

(Courtesy of nxtasy.org)

Jun 9, 2007

Books people really want?

The comment by Meefus the Great in Rick's last post on this blog makes me wonder... Just what are people really looking for in an NXT book? Do people want theoretical instruction (words with illustrative figures), models to build, or hacking ideas? Personally, I'd like one thorough handbook for various mechanisms that could be used in any robot, but I'd also like "cool" models (not too complicated) that teach me to use those different mechanisms. Are you game for an informal poll?

Here are some response options:

A. Traditional robot-building education (words with appropriate illustrations) including subjects like complex mechanisms, robotic theory, advanced programming for LEGO MINDSTORMS NXT...
B. Simple but cool models with detailed instructions for building and programming.
C. Complicated models with clear building steps and complete programs.
D. Models with a mechanism theme---walking robots, advanced wheeled robots, grabbing robots, learning robots....
E. Robots that show some artistic creativity---characters from stories, models with non-LEGO materials added...(I'd put Jim's Mayan Adventure book here)
F. Hacks, hacks and more hacks!
G. A handbook for creating digital versions of NXT models (I had to throw this one in : )
H. Your own wish list item---Please explain!

Feel free to elaborate.

I haven't posted for this purpose, but assuming that NXT publishers (and authors) are reading this blog, this is your chance to tell them what you are really interested in. Who knows, you just might get it!

Sample Page: LEGO MINDSTORMS NXT Idea Book

Here's another sample page from our upcoming MINDSTORMS NXT Idea Book, published by No Starch Press. (Click on the graphic for an enlarged view).

While the book includes an introduction to the NXT as well as chapters on theory and design, its main focus is on detailed building and programming instructions.

Over the last few months, we've received lots of feedback from youth, parents, teachers, beginners and others who say, "We need more detailed building and programming instructions!" This book aims to meet that need.

Several readers of this blog have asked for more details about this book. More information will be forthcoming soon. In the meantime, you'll see more sample pages like this one in the weeks ahead.

Jun 8, 2007

Control a Pneumatic Valve from the NXT.

Courtesy of Jim German of Motocube.

Using the Sensor Building Kit for NXT with PCF8574 IC, the SN754410 from Texas Instruments and some fancy wiring, Jim was able to control a Pneumatic Valve from his MINDSTORMS NXT.

While Jim mentions that this design could be improved (it requires a 24v power supply for starters) it is a good proof of concept. I can see a new range of home-grown pneumatic robots taking over the world... or the living room.

The full writeup is found here: Pneumatic Valves via Motocube

Fair: GAME ON Bluetooth remote with W300i

5 and 6 June, were Daniel and I attending the fair: GAME ON, in the Netherlands, this was a fair mend for students to see what they can do with technic in their future.

We had a large LEGO MINDSTORMS stand. I was showing the photo robot coco5 and I discovered that the NXT did work with these Sony Ericsson models: K510i, W300i and Z710i.

Looking at the list in the NXT Mobile Application Documentation.zip I noticed that this W300i is missing.
But I can confirm that if you put the version mend for the K510i on the W300i you can use that phone to remotely control the NXT.
Click here for the link to the bluetooth page.

NXT designers deserve a break

Remember the recent discussion on this blog about whether or not it's legitimate to sell building instructions?

A well-designed model can take days (and weeks) to design, build and rebuild.

Creating CAD models with MLCAD, POV-Ray and LPub ( is tedious, hard to do right and SLOW, SLOW, SLOW! I'm not sure people understand how much time it takes to create accurate and understandable CAD building instructions. Yesterday, I set LPub running on a rather simple robot and it took over two hours! (I have a 1.66 GHz processor) If I only had to run the program once, it might not be so bad, but every modification requires running the entire file again. It's not uncommon to run the instructions 10-12 times before they come out right. Perhaps, if I could use the newer versions, it might be a bit faster, but I can't. After the instructions are "done", Rick tries them out and then I have to address every problem he finds---some of which require significant changes in my MLCAD files.

After the building instructions are ready, then there are programs to write and test, screen shots to take (and retake). Then you need to explain the program. Don't forget, all the building instructions and programming screen shots then need to cropped and assembled in some kind of desktop publishing format. (I use Photoshop and InDesign.)

It's no wonder we don't find many accurate NXT model directions on the Web. They require a LOT of long tedious hours of work. Anyone who takes the time to create good models with accurate and clear building and programming instructions deserves to be paid well for his or her efforts.

"Building Robots with LEGO MINDSTORMS NXT": A Review

This book is out this week. What follows are some first impressions. Readers, including the book's authors, are encouraged to add more detail:

One of the book's strong suits is its non-intimidating style. The book is easy to understand and follow, with clear explanations throughout.

Beginners will appreciate the primer on NXT's basic elements: sensors, motors and Technic parts. Beginners will also appreciate the book's overview of building techniques, including an in-depth examination of NXT gearing.

Advanced users will enjoy the chapter on pneumatics, and the brief but fun chapter on building Sumo robots. Both beginners and advanced users will appreciate the chapter on building animals, as well as the chapter on building robots that walk.

There are no complete building instructions in the book, which is probably deliberate. The book focuses on construction principles and design theory, leaving it to the reader to design their own creations. That said, there are a few design ideas offered to get the reader started.

The chapter on programming is only an overview, without detailed instructions. A more in-depth look at NXT-G would have been helpful for the beginner. However, there are brief overviews of RobotC, NBC, pbLUA and LeJOS NXJ for the advanced user.

All in all, the book is a great reference work, especially for those new to the NXT. Teachers will be able to adapt the material for classroom use as well.

Email question from a student Part 2

Okay, here's one method for determining if the sensors are returning all True values or all False value or a mixture of values.... This means in my previous post that we're talking about a condition of (1 - 1 - 1) to get the Switch block to execute a True path - any other combination will have the Switch block execute the False path.

One of the easiest ways to do this is to use a Logic block configured to do an AND operation. Read over the Logic block's help files to learn about the other options (OR, XOR, NOT), but for now all you need to know is that the Logic block will take two logic values (one in data plug A and one in data plug B). The AND operation simply looks at the two values and returns a logic value of its own (coming out of the last data plug, called Result). If both values (A and B) are True, then the Result is True. If both values (A and B) are False then the Result is False. If one or the other (A or B) is False, then Result is False. So, the only way you'll get a Result value of True from a Logic block is if both A and B data plugs have a True value coming in.

Next, we take that Result from the first Logic block and run it a second Logic block (data plug B in my picture) configured to do an AND operation. I take the final sensor's logic value (the Touch sensor in my picture) and connect that sensor's Yes/No data plug to data plug B on the second Logic block. I then run a wire out of the second Logic block's Result data plug into a Switch block's data plug.

See if you can figure out what happens now that you understand that both Logic blocks are performing AND operations on the A and B values sent to them. By using just two Logic blocks, you can check to see if all 3 sensors are reporting True or all 3 are reporting False. All it takes is one sensor to report a False and the Switch block will receive a False signal. Follow along and test this little bit of programming and you'll figure it out.


Email question from a student

I received an email earlier today from a 7th grade student in Utah. Here's the (edited) question:

"How can I program my robot to make more than 1 yes-or-no decision. I have a robot that looks at 3 different sensors but I'm only using sensor logic values and not numbers. The switch block only lets me do one True or False condition."

Great question! And I certainly understand why you're confused. Rather than email the answer, I figured I'd share this with others because if one person is asking, I'm sure there are others. So, here's one option (option #2 will be provided in a separate blog post):
I don't know the details of your robot, but let's just assume that your robot's 3 sensors are Touch, Sound, and Light. You've configured the trigger values for each sensor (For example, does the Light sensor detect a light value less than 20 - true or false?) and are using the logic data plugs to take the True or False response from each sensor.
You didn't state whether all 3 sensor logic values must all be True or all be False, so this example will show you how to make decision based on a mixture of logic values, okay? Let's look at the possible options that can be returned. I'm going to write down all the possible options that could come from 3 sensors in the following format: Light - Sound - Touch with a 1 indicating True and a 0 indicating False. For example, if the Light sensor is True, the Sound sensor is False, and the Touch sensor is True, then I would write 1 - 0 - 1. Got it?
Okay, next we need to look at all the possible options?

Light - Sound - Touch

0 - 0 - 0

0 - 0 - 1

0 - 1 - 0

0 - 1 - 1

1 - 0 - 0

1 - 0 - 1

1 - 1 - 0

1 - 1 - 1

Verify that I've got them all, but I think you'll find that that's it... I've provided everything from all False to all True and everything in between. Now, count them up. There are a total of 8 possible combinations.
Using this, I need to figure out how to program a decision-making procedure that can account for 8 possible combinations. And to do that, I'm going to use the Switch block that you talked about in your question. You are correct that the Switch block only provides 2 possible options when using a Logic value - True or False. What I think will surprise you is that you can place a Switch block inside a Switch block inside a Switch block. Yes, that's 3 levels deep. By doing this, you can check the status of each sensor, one-at-a-time - based on True or False response, another Switch block will be used to check the status of the next sensor (True or False). A final level of Switch block will be added to test the last sensor.
Take a look at the image I've provided here and you'll see how this is done. Starting from the left, you'll see the first Switch block (SB-1) with True or False path. Follow it and you'll see 2 new SBs (SB-2 and SB-3), one in the True path of SB-1 and one in the False path of SB-1. Follow these and you'll see 4 new SBs, 2 in the True path of SB-2 and 2 in the False path for SB-3. And because each of these SBs have a True/False path, you will find that you have a total of 8 possible paths that can be traced.
If this is confusing you, just trace each possible path with your finger and keep count. Use the circles in the right image to represent each switch - blue lines are True and red lines are False. If you're still confused, the best solution would be to duplicate my image in NXT-G and experiment - it'll make sense if you think about it for a while. Thanks for the question - and option 2 will be posted shortly. In that option, I'm going to show you a way to use logic values to determine if all sensors are True or all sensors are False.

Light sensor

Sound sensor

Touch sensor

A polite request from LEGO

I received a polite request from LEGO... and being that I'm just as guilty as the next person for doing this, my apology will be in the form of a post to fix the requested problem. So, LEGO, here is my way of saying... "I'm sorry" :)

1. It is LEGO, not Lego. All caps. All the time.

2. It is not Mindstorm (singular) or Mindstorms (plural)... it is MINDSTORMS. All caps. All the time.

3. It is not MindStorm or MindStorms... again, MINDSTORMS. All caps. All the time.

4. It is not Rcx or Nxt or rcx or nxt. It is RCX and NXT. All caps. All the time.

Now, LEGO, that said... I will NOT correct, edit, and/or delete posts and comments that use them incorrectly... I don't have the time and, quite honestly, people type fast (myself included) and frequently these little errors are going to pop up... sorry. But for the record, I have now posted a "general use" policy and have done my little part to try and educate our readers. You're welcome ;)


Jun 7, 2007

RoboGames - San Francisco June 15-17, 2007

If you live near San Francisco and may be looking for something robotic to do that weekend...head on over and take a look at the world's largest open robot competition. The 4th annual RoboGames is sure to "spark" some interest for builders and spectators alike. There will be many different classes of robots from LEGO MindStorms to fire-spitting behemoths...and featuring competitions in over 70 different events: combat robots, walking humanoids, soccer bots (Robot World Cup), sumo bots, and even androids that do kung-fu. Some robots are autonomous and some are remote controlled.

LEGO Challenge (Line Running Challenge)
LEGO Open (Robot Design Contest)

If you go send me some pictures! I'll post them here.


World Robot Olympiad 2007

The previous blog brought up the World Robot Olympiad (WRO), a LEGO Mindstorms competition, which will be in Taipei, Taiwan November 17 & 18, 2007 (thanks Rick).

There are regular competitions for primary school, junior high school, and senior high school students: "Robo Rally" and "Robo Puzzle Race" for primary students, "Robo Ambulating Rally" and "Train of Alishan" for junior high school students, and "Robo Sorting" and "Alishan Timber Loader" for senior high school students. There is also an open competition with the Theme: “Civil safety, security and emergency response” (sounds exciting, but this link has yet to provide the details).

Since many of the readers of this Blog are only familiar with FIRST LEGO League, could those readers that have been to the WRO please share their experiences with the rest of us. (You may include links to your own picture & videos you have taken at previous WRO competitions, and to your team's website.)

Jun 6, 2007

NXT Used for Helping Jamaican Innercity Children

Marvin Hall is using the NXT in a robotics program to educate inner city Jamaican children to help keep them away from the streets.

More information about Marvin Hall and this program can be found here.

Which One is the Robot?

The robot is the one on the left. :-)

Read more.

NXT Telescope?

I saw this photo on Flickr. Does anyone know how it works?
Some related photos are here.

Jun 5, 2007

Winners of the NXTLOG Challenge #1

Winners have been posted for NXTLOG Challenge #1... read about them here.

CHAMPION'S AWARD to Newsboy912505 for the Nanobot: An Entry In NXTLog Nanoquest

ROBOT DESIGN AWARD to BSomerville for the BSomerville's FLL robot!

ROBOT PERFORMANCE AWARD to r01000 for the FLL Robot


CREATIVE USE OF NXTLOG AWARD to Kang the Searat for the The Nano-Brickyard

Steve Hassenplug was given an Honorable Mention award for being the first to submit a challenge entry... Team Hassenplug's Nano Quest FLL '06 bot

Jun 4, 2007

Grandparents and NXT

I wonder if LEGO has ever considered actively marketing the NXT to people nearing retirement (Baby Boomers)? According to USA Today, this is the wealthiest group in the U.S. NXT is almost the perfect product for grandparents---more brain-stimulating than crosswords or Sudoku, and a very high "cool" factor with the grandchildren. Are any of you grandparents out there using NXT with your grandchildren?

Winners Announced for the First NXTLOG Building Challenge

More details are here.

Problems with the LEGO Education Web Site?

As of June 3rd, you can still order from Lego's Education web site, but there's no availability information about ANY of the products on the site. In other words, you can't tell which products are in stock and which are not. The site is here.

Does anyone out there know what's going on with the site, or when a "fix" will be forthcoming?

Jun 2, 2007

NXTLog Building Challenge #2: Quadruped

NXTLog just released the next NXTLog building challenge. This time the challenge is to design and build a quadruped: a robot that walks on four feet. Once again, there's no limits to the sensors, motors, etc. that you can use, and judging is based on how innovative the design of the robot is, how well it works, and how well the robot is documented on NXTLog.

You can read the announcement here.


Jun 1, 2007

NXT Idea Book - Second Look (Jonathan Daudelin)

The LEGO Mindstorms NXT Idea Book isn't just for people who already have the NXT! For those readers who don't yet have the NXT but are interested in getting one (or for those who are interested in getting a second one), I wrote an Appendix about the differences between the Retail base set and the Education base set. It explains some of the exclusive features of both versions, and gives advice on which one to get.

Above is a screenshot of one of the pages in the Appendix - click on it to see a larger picture.

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