Jan 31, 2010

Deconstructing the dSwitch

Dexter Industries was kind enough to send me a dSwitch to try and so I anted to post some of my impressions and tests with it. First, it's seems fairly well built - up to and including tripping over it (OK, I'm a klutz) I had no problems with the casework of connections falling apart... something I'm actually rather concerned with in any device that potentially is carrying household current. Using it could not be easier - you can use a single custom block to toggle the switch "on" or "off" in a very natural way (power users - you can also just use a Motor block in NXT-G to do the same, this is not complex hardware to control).

My first use for this, after just testing it out, was as a Christmas Tree "driver": plugging the tree into the dSwitch with the NXT & sound sensor in control allowed me to make a sophisticated "clapper": one clap to turn on, two claps to turn off, three for a random pattern of flashes, and four claps to "set the trap". When the NXT detected four claps, it shut off the tree and monitored the ambient noise in the room... if it went above 50% of the ambient value, the NXT started flashing the tree. This allowed for a neat "ghost in the Christmas tree" effect. You could set up the tree to surprise the first unsuspecting person to enter the room, which is more than a little surprising. From this it's a short jump to a "surprise" system for folks breaking into a house (open the door and the radio goes on, or light flash... even in distant rooms, with multiple NXTs and BT connections)... or a little sibling detection system (have the NXT not just monitor when somebody entered your room... but have it actively startle them with a light or loud sound. Dave Astolfo's use of an NXT-controlled thermostat system in a aquarium is another good innovative use for this... and I'm sure there's a lot more.

I was also impressed by the speed it could toggle. To be honest, I wasn't expecting much - after all, you don't flick a light switch rapidly most of the time, and relays are often not the fastest things. But in tests, I could shuttle the dSwitch between off and on with an interval of just about 0.01 seconds... roughly 100 Hz (faster than this it "locked up", evidently not completing the opening of the relay before the command to close it again was sent). This allos a lot of nice fast applications for it, especially with rapidly responding lights (like LEDs)... the dancing lights example on the dSwitch page is but one example. You could essentially use ganged LEDs like this as a poor-mans computer-controled strobe light, which certainly could be interesting.

The only real cautions I'd mention here are it's size (it's big, too big for most mobile robots... but if it's mobile, what are the chances it would have something that needs to be plugged into a wall anyway), and the same caution I'd use when plugging anything into a wall socket. When you start messing around with houshold current, you need to be aware of shock hazards, and the same should apply here. But the dSwitch seems well made in this regard too - using UL listed components appropriate for the current and voltage limits, and grounding the system.

I'll be curious to see what folks come up with using "sensors" (actuators?) like this. I'm starting to look at my toaster, or my wife's automatic towel warmer, with a new eye towards DIY ideas... let the user beware!

Jan 30, 2010

Follow the Line, workshop

Last Tuesday I gave a workshop at a group of 15 7-9 year olds at the school Wittering.nl. The kids already participated in the FLL and won places for the country final on February the 6th. The asked if I could help them in doing more with sensors, in their FLL robot.

So we did a workshop in building and programing the 5 minute robot from NXTprograms.com.
we also added an Ultrasonic sensor to detect the end of the line (actually the wall of the playing field) in the Smartmove mission.

It was great fun and all groups build and programmed a good working robot, with the new color sensor, some even adapted the smooth line follow program to an old style lightsensor.


Jan 28, 2010

NXT - Snow Crawler

Here is another great robot from long-time reader bazmarc.

"Take an 8263 Snow Groomer alternate model, mix it with an NXT kit, wait for a sunny winter day and you get this great little Snow Crawler -- i really had fun filming it and i felt like a kid again (ok so i often do :) "

Damien Kee

Streaming Audio into a NXT

Now here’s a really cool idea. YouTube user “gloomyandy” has devised a way to stream audio directly into the NXT using Bluetooth and leJOS. I had no idea that this was possible, and it opens up all kinds of ideas. Good Job!

Jan 27, 2010

More Technologies for You to Explore

There's a video at the end of this post... watch it. It's narrated by the Editor in Chief of WIRED magazine, Chris Anderson. Many of us have met Chris at WorldFest where he demo'd his DIY Drone (complete with NXT). Chris and his kids are LEGO fans, too!

The latest issue of WIRED (issue 18.02) is titled "The New Industrial Revolution" and it's a great issue. Kids (and adults): Find a copy of this issue and read the article. This is your future. DIY fabrication, on-demand 3D printing, metal cutting, and milling. Dream it - design it - build it yourself (or with some help via outsourcing the work). (The latest issue isn't yet available online - keep checking here if you'd like to read the online digital article when it becomes available.)

Also this month, the latest issue of Make: (issue 21) is out - it, too, is all about DIY Home Fabrication. Want an open source plasma cutter (I do!)? You'll find an article on it and links to build your own. Want more info on the MakerBot? It's in there. (There's also a short article on a new book that shows you how to build your own CNC machine - written by some guy names James Floyd Kelly - the article's a bit amateurish but you might like it). There are also links and an article for building your own 3D scanner. Definitely an issue to grab.

What does this have to do with NXT robotics? Not much. But how cool would it be to build and operate a LEGO CNC machine that can cut plastic and foam? What about a LEGO 3D Printer that prints its own plastic bricks that you design? (LEGO - send my commission checks to the address on file.) I'm totally serious - as prices drop on these items, it's not unreasonable to think that one day LEGO may offer the LEGO MINDSTORMS Home Fabrication Kit, complete with CNC machine, 3D scanner, and 3D printer. I don't care how much - I'd buy two.

Anyway, enjoy the video below - and definitely hunt down the magazines and grab a copy of each if you can. If all these machines are totally unfamiliar to you, now is the time to start learning about them... like I said - this is your future.

Jan 26, 2010

RobotChallenge 2010 in Vienna

On 20th and 21st of March, in Vienna the RobotChallenge 2010 will take place, Europe's biggest robotics contest.
Form a press release of the hosts:
"Participants from all over the world will compete against each other with self-made, autonomous robots. As a novelty this year, the European Robot Sumo Championship will coincide with the RobotChallenge 2010; celebrating its premiere in Vienna.
On March 20 and 21, 2010, the Vienna science auditorium will transform into a setting of one of the biggest robotic competitions worldwide. Participants aged 12 - 60 years will compete with their robots in eleven disciplines on 2,000 square metres. The Austrian Society for Innovative Computer Science (InnoC), in cooperation with the Austrian Ministry of Science, expects more than over 200 robots from all over the world. "During the last few years the RobotChallenge has established itself as an international event in the area of robotics. "Participants arrive from over 15 countries every year," says Roland Stelzer, organiser.
The RobotChallenge 2010 consists of eleven disciplines, offering suitable contests for beginners as well as for experienced robot designers. Aside from the traditional contests Line Follower, Line Follower Enhanced and Puck Collect, so-called humanoid robots - modelled after the human form - compete in two disciplines.
This year, the European Robot Sumo Championship will be held together with RobotChallenge and European Championships will be awarded for six Robot Sumo weight classes for the first time. As in the traditional Japanese martial arts, the robots try to push the competitor off the ring.
Extraordinary and particularly original robots can be admired in the Freestyle Exhibition. Considering the creative diversity displayed in previous years, numerous oddities in the world of robots can again be expected this year.
Aside from the benefit of free admission, the audience can expect a suspenseful and varied show, as well as the odd chance to look over robot designers' shoulders during last minute preparations."
Deadline for free registration of participants is February 28,2010.

Guest Blog - Dr. Bartneck

I received the following from Dr. Dr.Christoph Bartneck at Eindhoven University of Technology:

Here at the Eindhoven University of Technology, in the department of
industrial design, we completed another edition of our master class "Lego
Beyond Toys". The student build a WiFi bridge, a parachuting robot, a color
LED brick, a suction cup climbing robot and a infrared positioning system.

Read more about the project here.

Thanks, Dr. Bartneck, for the information!

Regulating an aquarium's temperature with a NXT

Dave Astolfo is pretty productive presently: following the DualGrip NXT Rover from last week, he has published a new NXT creation of his: the dSwitch Aquasaurs Temp Monitor.
It monitors and regulates the heat in a aquarium, using the dSwitch from Dexter Industries:
"The NXT is programmed to monitor the temperature using the LEGO temperature sensor and the dSwitch NXT-G block is used to turn the light on and off based on temperature thresholds.  My current setup has the dSwitch turn the light on when the water temperature is below 72F and turn it off when it hits 79F.  With NXT-G I am also able to control how often it polls the temperature to ensure that the granularity of monitoring is over a longer period of time."
Interesting application!

Jan 25, 2010

The Polar Bear from "Endangered Species"

Here's the fourth animal-like robot I have built from Fay Rhodes' book "LEGO© MINDSTORMS NXT Robots Alive! Endangered Species": the Polar Bear.

You might have already seen Damien Kee's nice video on it; like him, I love particularly Fay's idea of making the front legs looking like they're walking.

Building time: around 90 minutes.
Programming time: 10 minutes.
Difficulty level for children: advanced.

Jan 24, 2010

Side Show Alley Clown

Here is a version of the popular sideshow alley game where you pop the balls into the clowns mouth and try to get them lined up in the same slots.

It's made just from a single NXT2.0 Kit.

My wife thinks it's a scary looking clown (Think Stephen King's 'IT') but it's best I could do with limited parts :)

Damien Kee

Jan 22, 2010

SUPER size ballsorter

Ronald mcRae, creator of some impressive models, build this supersized MINDSTORMS 1.0 ball sorter.

Check out some if his other models too.


King's Treasure Parts List for Education Set/Resource Set

UPDATE: Although the PDF files here show the Color Sensor as a required component, that is not the actual case - the Light Sensor can easily be substituted and the challenge modified to work with grayscale. Sorry for the confusion.

Chris Smith has been hard at work putting together two PDF files:

1. A list of parts required for King's Treasure but not found in the Education Base Set


2. A list of parts required for King's Treasure but not found in Ed Base Set plus Resource Set

Click on a link above to download the PDF.

LEGO Education created and sold a parts pack for The Mayan Adventure that provided parts for Education Base Set owners so they could build the robots in that book... I have no word or idea whether LEGO Education will do the same for The King's Treasure, but I'll be inquiring and let you know when I know something.

Thanks, Chris - I know many teachers who have been anxiously awaiting this!

Jan 21, 2010

NXT 1.0 Line Following and Light Sensor Calibration

I have updated the original NXT 1.0 Line Follower project at nxtprograms.com to improve the original programs a bit and include a new "proportional" line following program. I also included some separate light sensor calibration utility programs and some discussion of light sensor calibration, as calibration can be a somewhat confusing concept in practice (although it can simplify your programs and/or make your robot more flexible once you understand how to use it).

Comparing this to my new NXT 2.0 Line Follower, with essentially the same program, I notice that it doesn't perform as well. I think this is for two reasons: NXT 2.0 programs execute faster than 1.x, and my older 1.x robot design is inferior. In particular, I think the light sensor is too far ahead of the wheels. Making the wheel track (left-to-right) wider would probably also help. Give a try at making it better!

Line Following with NXT 2.0

I have received a lot of questions and requests about line following over the last several months. Some requests are coming from the FLL direction and such, but also users of the NXT 2.0 retail kit are wondering how to do line following using the color sensor, which is somewhat harder and/or less obvious than with the (NXT 1) light sensor.

So I have posted this NXT 2.0 Line Follower project to show two ways to do this (there are many other approaches), a simple "Two State" line follower program, and a more complex "Proportional" line follower, which is smoother and faster. In addition, the Proportional version includes an automatic calibration sequence, where the robot automatically scans the line and surface to determine the minimum and maximum expected brighness values on its own. These programs will only work on NXT 2.0. I will follow up with some info and programs for NXT 1.0 users later.

Although under good conditions you can make a simple line follower using the color sensor in "Color Sensor" mode (if it will read, say, black for the line and white for the floor), you are better off using the color sensor in "Light Sensor" mode, where you can get a numeric brightness value from the sensor, so both programs here use it this way. However, two complications arise out of using the color sensor in Light Sensor mode. First, "calibration" of the sensor (determining the minimum and maximum expected light values) is not supported by the NXT software. The Calibrate Sensors menu command as well as the Calibrate programming block only support the original (NXT 1) light sensor, not the color sensor in Light Sensor mode. So you need to do your own calibration. But then the other issue is that the "View" feature on the NXT brick menu (e.g. View Reflected Light) again only supports the old light sensor (the View Color choice will only show the color sensor in color sensor mode). So while doing your own calibration, you will also want to use your own program to do this.

To keep the simpler line following program as simple as possible, the "Two State" line follower program requires you to sample the light values and modify the program as necessary. As a tool to help with this and similar uses, I have posted an NXT 2.0 Light Meter project (you can use just the program if using it to calibrate another project such as the Line Follower). The Light Meter program also allows you to change the sensor option of red/green/blue/ambient, which makes it interesting for other experiments as well.

As a more advanced approach to the issue of calibration, the "Proportional" line follower also includes an automatic calibration sequence to eliminate the need to calibrate manually or modify the program based on the conditions.

WorldFest - April 2010

So, who's coming to the party!?

Once again, teams are heading to Atlanta for WorldFest... I'm looking forward to this April's competition - the FLL challenge this year just seems more difficult. And more fun to watch. I've yet to see a perfect score (not saying they don't exist), so I'm hoping to see a few during the event.

Are you coming? Introduce yourself and your team! LEGO will once again have a booth with plenty of robots, books, and giveaways (I'm guessing on that last one, but they rarely disappoint). Come by the booth and say hello to the MCPs and LEGO folks who make the trip. I'll try to get a list of all the MCPers and/or book authors who will be there... bring your books and get them signed.

Be sure to look me up and say hello!


Jan 19, 2010

International Translations for the Classroom

It just occurred to me that, as a self-publisher, I can give anyone the right to translate and share the text portion my Endangered Species book. Therefore, I want to officially post this notice:

Any non-English-speaking person who has purchased my Book, Robots Alive! Endangered Species, has my permission to translate the text portion of the book into another language---with one stipulation. The stipulation is that you send me a copy of the translation, so that I can make it available on the book's website (and other websites you recommend).

It can be offered in Word or PDF form---though I recommend PDF form.

I also request that you have your translation reviewed by other people who are fluent English-speakers and that you identify yourself as the translator, so suggested corrections can be sent to you.

The documents may be sent to author@thenxtzoo.com.

New NXT Inventions/Contraptions

While browsing some of my favorite sites today I ran across a couple of videos.

The first is from Xander Soldaat is the completion of an enormous NXT construction that was first shown at Lego World in Zwolle. This is the High Bay Storage warehouse. Xander just completed the programming of the huge crane that is a part of the system. You can read more about it on Xander’s BLOG, I'd Rather Be Building Robots . Here is video of the crane.

The other that I found was on NeXTSTORM’s site

It is a NXT project called just Tube IT!

Congratulations to Xander ans NeXTSRORM for such wonderful inventions/contraptions.

If life gives you LEGO®, build ROBOTS,


Jan 18, 2010

The Gorilla from the "Endangered Species" book

So here's my next build of an animal-like robot from Fay Rhodes' "LEGO© MINDSTORMS NXT: Robots Alive! Endangered Species" book: the Gorilla.

Again, Fay did an extraordinary job of implementing the animal's appearance and way of moving.
My favorite robot from the book so far!

Building time: around one hour.
Programming time: 10 minutes.
Difficulty level for children: advanced.

Jan 17, 2010

Quadruped Robots

Walking robots have always seemed fascinating to me. There's something amazing about a robot walking like a real person or animal. That said, I've never actually built a walking robot of my own. I tried a couple times when the RIS was around, but didn't succeed. However, recently I've been thinking about how to make a quadruped robot using the TETRIX system with the NXT to get a larger and more powerful robot that could be capable of navigating the outdoors. Right now I don't have enough TETRIX materials to build one (they're pretty expensive), but I'm hoping to get them sometime in the near future.

It's amazing how complex walking motion is! I may be wrong about this (I certainly can't prove that I'm right), but it seems to me that a quadruped needs at least 12 motorized joints to achieve full animal-like walking capabilities. Now, I know that many people have found great ways to achieve quadrupedal walking motion with much fewer motors, but I think these robots have limitations that prevent true animal-like motion. One possible setup of motorized joints in a quadruped could be eight "shoulder" joints and four "elbow" joints, as in the following figure:
The type 1 shoulder joints and elbow joints are, of course, for lifting, extending, and lowering the feet during steps. The need for the type 2 shoulder joints is a bit more subtle. Take a look at an above view of a quadruped, showing its center of gravity (COG):
The square formed by the feet represents the "support zone" of the robot. As long as the COG is within this zone, the robot should stay balanced. The closer the COG is to the center of the zone, the more stable the robot will be. Therefore, the current pose is a very stable one. Now, if we lift the front-right foot up to start taking a step, look at the position of the COG relative to the new support zone (the triangle) formed by the remaining three feet:
Now the COG is right on the edge of the support zone. This means the robot is just on the verge of tipping over, and is very unstable. In order to fix this problem, we need a way to shift the COG inside the triangular zone. One way of doing this is to use the type 2 shoulder joints to side-shift the robot away from the foot being lifted. Although there are other ways to shift the center of gravity that use less than four motors, the type 2 shoulder joints would also enable the robot to realistically turn and do other animal-like motions.

One amazing example of an animal-like quadruped is the "Big Dog" by Boston Dynamics. You can see a video of it here.


DualGrip-NXT Rover

MCP Dave Astolfo has published a new NXT robot of his: the DualGrip.
As the author states:
"The idea was to have a treaded robot that could navigate varying terrain, turn quickly and of course, climb.  Based on my experience with my other robots using the same tracks (eg UNV and DynaTrax), I found that they were not very good when it came to inclines.  I figured that the LEGO rubber wheels have great traction on most surfaces, so why not slap a set of them along with the treads."
The point with the DualGrip is that it switches from tread drive to wheel drive when it encounters an incline - pretty good idea, isn't it?

Have a look at the three web pages associated to the robot - there's a lot of information on the DualGrip to be found, including two more movies.

Jan 14, 2010

HiTechnic LDraw parts are here!

Philo's been hard at work again! Check out a writeup on these new LDraw parts of the HiTechnic sensors and motors and multiplexors. Click here for the link.

Thanks, Philo!

Haiti Needs Help

I have a friend here in Atlanta who is from Haiti... he is not able to reach family back home.

I'd like to ask all our readers to, if possible, make a donation to the Red Cross or other organization that will be providing assistance to the citizens of Haiti after the horrible earthquake yesterday.

Keep all those people in your thoughts and prayers.


Jan 13, 2010

NXT 2.0 Dial Remote Control

I have posted an NXT 2.0 Dial Remote Control project, which is an updated version of the NXT 1.0 version posted last year. This is a simple-to-build and sturdy remote control designed for NXT-to-NXT Bluetooth control, which has a somewhat unique feature in that you can get very smooth and progressive movements based on the way that the dial control works (the speed of the dial rotation maps to the robot motor speed instead of the usual dial/lever position technique). This control works particularly well to control the Forklift project.

In addition to the Bluetooth programs (one for the remote and one for the controlled bot), the project includes a program that shows how you can use the Dial Remote Control to control two motors via wires, with only a single NXT kit. Along these lines (wired remote control), I also posted a separate Mini Rover with 3-Button Remote project that shows a much simpler wired remote program using only the 3 buttons on the NXT.

To throw in something new for the Dial Remote Control over the 1.0 version, I added a touch sensor to give you five total actions to choose from, and also a bar to prevent you from accidentally pressing the dark gray program abort button by mistake when using the remote.

The NXT 2.0 Dial Remote Control is similar enough to the 1.0 version that I didn't make a new video, but here is a video of the 1.0 version controlling the 1.0 Forklift project.

Where to get more parts.

This is the follow-up to “Not Enough Parts” published here on December 23, 2009.

Many of you are content and build some interesting and wonderful things using just one NXT kit. There are numerous books published (like the ones listed over there on the right side of this page) about constructions requiring only one kit and web sites that also concentrate on building with just the parts included in just one NXT set (like nxtrograms.com). Some folks like to see just what they can do with the limited quantity parts included in one set, others just want to save a few dollars (euro, whatever) by only using one kit. But for others, this is enough.

It is my contention that the commercial NXT kit (either the original 8527, the newer 8547) or the Education Base set (9797) are just starter sets. You can build many things with one NXT kit, but if you want to build to the limits of your imagination (assuming your imagination is bigger than a standard set) you are going to need more parts. The question is… Where do you find more parts? Believe it or not there are lots of places to buy more parts!

Start with a little research. What do you want? What do you need? The first place I go is peeron.com (http://www.peeron.com/). I look up a set that I know has the part I want/need for example a 15 bean in the NXT 2.0 set number 8547. When you select the link for the part you will be presented with a new page that lists LEGO sets that have the part, and on the right hand side of the page you will see a box with listings of places that have the part for sale and the country where the vendor is located, some different colors for the part and even some estimated prices for the part. You know the drill, just select the link of the price and you will be transported to the vendors store. Many of the stores are on an unofficial LEGO Marketplace called Bricklink (http://www.bricklink.com/). I understand that you can buy almost any LEGO part currently in production and some no longer in production from Bricklink. You can scour Bricklink for any part you want and find multiple vendors for the same part. Choose your part, choose your vendor. Some vendors charge a shopping charge for each part you order, but most will combine parts orders for multiple different parts an give you a break on shipping.

Another place to find parts is the auction site we love to hate, eBay. eBay has gotten a bad reputation because of a few unscrupulous individuals who will take advantage of others. I use eBay all the time, for different things, but I (now) always, always, always check the seller ratings. If they have a low rating, I buy from someone else. I bought from a person with no rating once, got burned, but not as badly as I could have. Moral, check the seller ratings. Lastly, make sure you know prices. Sometimes folks on eBay will charge outrageous prices just because someone will pay them. Sometimes the item has a low price, but the shipping is outrageous. Compare the full price including the price of the item and shipping charges.

There are several ways to find parts on eBay. You can search for LEGO NXT, LEGO Mindstroms, or LEGO Technic (and several others) and you will be presented with a list of parts and sets for sale by various individuals and vendors. You can find sets and packets of parts for almost any part you want/need. I like the “Buy It Now” option because I know what I am going to get and what I am going to pay. Bidding on popular items often gets out of hand and you can wind up paying much more than an item is worth if you get caught up in bidding. Some folks like the thrill of the bid, some folks get good deals, I seldom get good deals with bidding.

Also on eBay there are eBay stores from several vendors, some items are “Buy It Now”, some are up for auction. One store that looks like it has many parts at what seems like reasonable prices is Specialty Bricks & Robotics (http://stores.ebay.com/Specialty-Bricks-and-Robotics); they look like they have a good selection and good prices.

Another very good resource is the online LEGO Education store at: http://www.legoeducation.us/store/ from there you may search for parts and purchase single motors, sensor or multipacks of sensors and almost anything LEGO has for sale. I find the store not the easiest to use, but I did find one link to a section of the store one link to a section of the store from which you can browse many NXT parts. Frequently you need to buy packages of parts. For example if you want some beams, you may find a package of beams. You can buy individual parts from Bricklink. For example at the LEGO Education store you can buy packages of beams that includes 5 beams each in sizes from 3 to 15 studs in length. A total of 35 elements for $12, a good price, but if you only need a few 15 length beams you might want to try Bricklink or eBay instead.

I have bought a few individual parts, but I prefer to buy a Technic set to get parts. The advantage is that I get a variety of parts, and a model to build before I use the parts to build other things. You can get sets from eBay, Amazon, LEGO and many other places.

If you buy from eBay, Amazon or any place that other than the LEGO store, make sure you know what the retail cost (and shipping) is before you buy. On eBay, if you are bidding you can get caught up in the moment and overpay just to get the item, or some of the “Buy It Now” options are listed for more than retail prices. On Amazon, if the item is sold directly by Amazon you can usually get it for less than retail or no more than the retail price. Be careful with Amazon Marketplace vendors, as some of them sometime sell for prices I feel are way out of line with the retail price. If you find the price is too high, just go elsewhere. The key here is to do your research in advance so you know what is a reasonable price to pay for the item.

These are just a few places to find more parts; I am sure there are more places. Do your research.

Research is the key to finding more parts!

If life gives you LEGO®, build ROBOTS,


Jan 12, 2010

Amazing Art

The creator describes this piece as a spider. But it with the music it reminds me of a violin. Whatever you think it looks like, you must admit it's very clever.

Remember the TV show, Battle Bots?

While looking around YouTube the other day I found this video of how some folks in a Russian(?) office let off steam. It is a form of “Battle Bots” and no ROBOTS were injured in the making of this video.

Be sure to turn down the volume! It is quite loud!

I hope you enjoy it.

If life gives you LEGO®, build ROBOTS.


Jan 11, 2010

First NXT book in German

After having blogged on THE NXT STEP's German sister blog Die NXTe Ebene about David Perdue's list of NXT books, I was told by a German publisher that, finally, the first NXT book written in German has been published (already three months ago): "Roboter programmieren mit NXC für LEGO® MINDSTORMS NXT" (which means Programming robots with NXC) by Daniel Braun.
It's a book for beginners on the NXT and on programming it with NXC; for further information, see my according post in Die NXTe Ebene.
Soon, I will receive a copy and subsequently will look into it in detail.

I'm happy to see the first NXT book appearing also in German and am hoping for other ones in the future.

Jan 10, 2010

New(er) Style Tread Links

A friend of mine, John Brost, recently asked me if I had noticed that there were two types of the new tread links out there. Surprise surprise, it seems LEGO has modified the mold slightly. The new tread links will work fine with the old ones - there's no difference in the parts that connect link to link. However, some small new "bumps" on the new treads do change a few things for robot builders. First, they tend to make the side-to-side stability a little better (a good thing). Second, it means that using them "backwards" to form large wheels now works only with still larger diameters. Mixing them in an alternating fashion makes small "old style" (?) tread link wheels work... but you'd have to pay very careful attention to make sure multiple "new style" links aren't adjacent, or you might end up with flat places in your wheels. As to the why for this, it might have been to increase the side-to-side stability, or it might have been to allow better flow in the molds and less rejects due to bubbles (suggested by Bryan Bonahoom, who knows much more about these things).

Now, if they would just come out with a rubber "shoe" for these links...

Jan 8, 2010

NXT Polar Bear

I just got my copy of Fay Rhode's 'Robots Alive!' and have put together the Polar Bear.

It's a great little build and I love how she's got the front legs to look like they're walking.

Damien Kee

Guest Blog - Alban

Reader Alban (from France) is pitting robot against robot in his video:

NXT V1 Scorpion vs NXT V2 Robogator!

Let's Get it ON!!!

Jan 7, 2010

Thank you, King's Treasure Book Buyers!

I want to say a special thank you to those of you who have purchased my latest NXT book - LEGO MINDSTORMS NXT 2.0 - The King's Treasure. I got word today that it's currently SOLD OUT and is being reprinted. (Amazon still has a few copies left, however...)

It took less than 2 months to sell out of the first run (compared to about 6 months or so for Mayan Adventure)... a pleasant surprise.

If you have ordered a copy and haven't received it yet, please be patient... the reprint order won't take long and Apress is likely to increase the size of the reprint order as they have in the past.

Thanks again for your support o

Another view on Fay's Komodo Dragon

Finally, I have found time again to resume my review of Fay's new book "LEGO® MINDSTORMS NXT Robots Alive! Endangered Species". After the NXT Frog, I've built the Komodo Dragon:

Being somewhat fragile and delicate in regard to the type of underground it is running on, the model is a very nice and elegant implementation of a reptile and mimics wonderfully the particularly reptant pace of this kind of animals.

Building time: app. 30 min.
Programming time: 3 min (the program is very simple)
Difficulty level for kids: medium

Jan 5, 2010

High Bay Warehouse Video is FINALLY here!

Back in October, there was a post here about the incredible Lego Mindstorms High Bay Warehouse

Joe Meno has posted an incredible video of the warehouse in operation at LEGOWorld Zwolle in 2009.  Incredible stuff, and I think we all want to see more video!

Updated Book Listing

David Perdue has updated his NXT Book Repository webpage with some new additions and some fixes (dead links, 1.0 vs 2.0 notes, etc).

Thanks for the updates, David!

Jan 4, 2010

Off roading at it's finest?

The video speaks for itself.  The "digital dashboard" is phenomenal, and the suspension is impressive.  This uses 2 NXTs, differentials PF motors, and more... just watch the video...

Here is the video (approximately 4 and a half minutes long):

And here is the website:  http://bouwvoorbeelden.nl/home_eng.htm

Jan 2, 2010

Beyond the Box: "Endangered Species NXT"

Below are two photos taken from the book, "Endangered Species NXT". They illustrate how you can creatively embellish the models in the book, using materials "outside the box". (Click on the photos to see larger versions).

The above photo shows how you can transform the book's "Komodo Dragon" into a dragon from classical mythology, using common Bionicle parts.

The photo above shows the book's sloth with "fur", using a feather boa from a local craft store.

These photos (and others like them) are included in the book, in order to spur the imaginations of builders. Kids, teachers and parents can then use their own, unique materials and parts to transform their animal robots into something new.

Jan 1, 2010

NXT 2.0 Forklift

I have posted an NXT 2.0 Forklift project, which is a variation on my original NXT 1.0 version. The NXT 2.0 version adds the use of the color sensor as a "warning light" to shine three different colors depending on what the forklift is doing (e.g. light flashes red and NXT beeps when backing up).

The forklift can do autonomous tasks with the help of the ultrasonic sensor, and you can also control it via Bluetooth remote control. The built-in remote control feature in the NXT 2.0 software can be used to drive the forklift, but it is inconvenient to control the lift because you cannot easily reverse the 3rd motor on the fly using the built-in remote control. Fortunately, Anders Søborg has provided this free PC Bluetooth Vehicle Remote program, which is more flexible, so instructions for using this are included. Anders' program works fine with either NXT 1.0 or NXT 2.0, so it is a nice upgrade for 2.0 users or a great new tool for 1.0 users (PC only, sorry no Mac version).

Instructions and programs to control this forklift by Bluetooth from another NXT will follow in my next project post.

Here is a video of the forklift in action:
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