Jan 31, 2008
On gizmodo.com, there's a nice article in connection with the 50th anniversary of the LEGO™ brick that features a timeline with milestones like the LEGOLAND, TECHNIC, Star Wars or MINDSTORMS sets. It also contains a lot of curiosity facts on LEGO™ (did you know, for instance, that one could reach the moon with stacking on each others only a tenth of the bricks that have been produced so far? Or that there are no less than 55,600 LEGO™ videos on YouTube presently?), the official anniversary video and a link to the "best LEGO sets ever" (a classification that certainly depends on the eye of the beholder to some extent, though).
I especially like the "Challenges" that are provided for learning more and expanding the functionality of the robots.
Jan 30, 2008
I've been playing a bit more with datalogging (check out the fantastic tips from Brian in the forums) and I've always wanted a robot that could come to me when I called it. The sound sensor is great for 'detecting' sound but no good for deciding where the sound came from. One way to figure out where the sound is coming from is to use 2 sound sensors.
So I built myself a little NXT head that had 2 sound sensors and a bit of foam in between.
"Sure it's pretty" I hear you say, but whats that foam in between the ears for?
Well I figure that if I had 2 ears, with some sort of dampening material in between, the ears would hear the same sound source, but at different volume levels.
ie. If I clapped my hands very loudly on the left hand side, then the left 'ear' would hear a certain volume and the right 'ear' would also register a sound, but at a much quieter level.
So I set up my head and start writing sound readings from both the left and right ears to a text file as fast as I can. I'm not too concerned with the sampling rate, as I'm more interested in the difference in sound levels for the same 'clap'
I take the results and put them through Excel where I subtract the value of the right ear from the value of the left ear to give me a difference.
Now if the clap happens directly in front (or behind) my NXT head, then the sound levels will be the same and the difference will be 0. But if I clap off to the left hand side, then the left reading will be higher than the right reading and my difference will be a positive number. If I clap on the right hand side then I'll get a negative number.
This graph shows the difference between the left and right ears with 3 test claps, once on the left, once in the center and once on the right.
From this I can see anything under -40 is a definite clap on the left and anything over +40 is a clap on the right.
So now I can write a program that takes the two sound sensor readings and subtracts one from the other. If the result is more negative than -40, I turn clockwise a small amount. If it is greater than 40, I mover counter-clockwise for a small amount.
I think with more sound dampening, I could probably get it to respond a little more accurately.
So I was wondering if maybe this construction could be used for something like a giant wheel or gear (turntable?), since sprockets can mesh with the outer rim of the circle to rotate it. And since the links have peg holes in them, you can put supports inside the circle:
You can also use the peg holes to put an axle hole or something similar at the center of the circle, so it can attach to a robot (i.e. actually be useful :-) ).
Any ideas for how to use/improve something like this?
This is just a design I came up with while working on another project, which I'll post about if successful. Ultimately, this robot was a failure because it's not powerful and can't steer (the treads are too close together), but it looked interesting. Also, since the treads go all around the robot, it can still drive when it's upside down or on either end, so that was pretty neat too.
Anyway, how useful/practical have you found these treads? I like their size and the fact that you can make them as long as you want, but then I don't like their slipperiness (although people have fixed that with stuff like liquid rubber), and they don't seem to "fit" very well on robots (lots of times they're either too long or too short).
Jan 28, 2008
Today even Google celebrates with LEGO their 50th anniversary!
The 50th birthday of the LEGO brick is in January 2008 and there is plenty to celebrate. Children all over the world have played with LEGO bricks for the past 50 years, and LEGO is still right at the top of many wish lists – just as it always has been. Industry and trade associations also recognize the LEGO success. Just before the turn of the millennium the LEGO brick was voted “Toy of the Century”, one of the highest awards in the toy industry, by both Fortune Magazine in the US and the British Association of Toy Retailers.
LEGO bricks from 1958 will even fit on today’s bricks. Read more.
MINDSTORMS features in Builders of tomorrow
From the website:
"This should run on any MIDP 2.0 phone, provided it supports the JSR-82 Bluetooth implementation.
•Basic settings allow you to easily change the way robots are controlled.
•No musical intros or fixed resolution settings.
Jan 27, 2008
It was a great day, and I hope some of you got a chance to look at the webstream, it was professionally done. I was standing close to the arena and heard a lot of the competition going on.
These are the results:
1st place University Twente Chamions Award: (going to Atlanta!)
Herta-Mechanics fom the Herta-Lebenstein Realschule in Germany (This was one of the cross border schools that were allowed to compete with us)
Second place and second place in Robot Challange:
icNRG as a friendsteam from Eindhoven
De Spaarlampjes from Johannesschool in Hillegom
First place in Robot Function and second place in robot Design:
3T Rox from De Telgenborch in Almelo
First place in robot Design and Programing:
C3PO also a Friends team from Den Haag
Congratulations to you all and I hope you had a great day.
More images will follow soon.
Jan 26, 2008
The Benelux final of the First LEGO League will be held at the University Twente on Saturday 26 January.
You can follow this live online, (just during the games) but you are also welcome to visit us, the 32 best teams of Netherland, Belgium and Luxembourg will show their robots and fight for a place in Atlanta.
There are also several Workshops MINDSTORMS and science demonstrations, I will show several demonstration models and some models from the IDEA book.
See this page for the location.
LDraw.org has a
We'd be interested in hearing from folks who have done successful conversions, especially those involving NXT creations.
(Graphic courtesy of Ldraw.org)
The LEGO Group® has published a document that describes the RC protocol supported by the LEGO Power Functions® RC Receiver.
With this guide, developers will be able to write software that remotely controls the new Power Function elements via an Infrared interface.
Jan 24, 2008
In my experience, the tan axle pin is the element most likely to be damaged when I'm teaching with the NXT or another Technic set.
As best I can tell, my students damage the pin tips when they are trying to remove it from another part, especially if they use their teeth (shudder).
Bent axle pins won't spin freely in a Technic hole, and they won't grip a hole well enough to stay in place.
If the axle side is stuck in a gear or a beam, you can use an axle to push it out from the other side. That's not an option with a number of Technic connectors, like the one shown in the photo above.
Sometimes, I can get a fingernail between the collar of the axle pin and the connector, but not always.
If I put something in the pin, like an antenna, I can grip the pin and pull it out easier. The antenna prevents the pin tips from getting crushed when I squeeze the pin half of the axle pin.
The below picture from the building instruction of box 8842 shows how LEGO recommends to disassemble some constructions, including how to remove an axle-pin. Note how the axle-pin is first stuck in a beam to prevent the pin getting deformed by the thin antenna size insert. This insert pushes the axle-pin firmly in the beam so it will have more friction then the (old style) Technic connector.
Do any of you have another method for separating these parts?
Jan 23, 2008
MCP Daniele Benedettelli, creator of many intriguing robots, has published a preview on his book
Creating cool MINDSTORMS NXT robots that is to appear in March 2008 at Apress.
The Table of Contents looks veeery promising.
"If you have a LEGO® MINDSTORMS® NXT robotics kit, then this site provides free building instructions and downloadable programs for several fun projects.
Projects designed for the young and young at heart!
Full building instructions with color photographs
No programming experienced required! You can simply download and use the programs provided.
Know some programming but want to learn more? Study the fully commented programs to learn how they work, and try modifying them or using what you learn in your own programs.
Check out the site here.
Jan 22, 2008
Vernier constantly comes up with new applications for its sensors, which can be adapted to the NXT. In the above shot, an NXT is using Vernier's UV Sensor to determine which of several sunscreens offers the most UV protection. The
In the above shot, Vernier's magnetic field sensor finds a magnet hidden under a walnut shell. The
While Vernier's NXT sensor adapter is relatively inexpensive ($39), its sensors are not; hence, they are better suited for the classroom (or for those with a rich uncle).
Jan 21, 2008
"I am pleased to announce the release of pbLua Beta 13y - whichis a replacement firmware for the LEGO MINDSTORMS NXT that runs right on the brick. It parses source code files sent to it via the USB or Bluetooth ports and runs the code.
Lua is a powerful general purpose scripting language that is very easy to learn, is fully documented on the web, and is used as the scripting engine in applications like Adobe Lightroom and World of Warcraft, to name just two..."
In the coming weeks and months, look for pbLua distributions that have a standard set of user files already programmed into the user FLASH area so that beginners can get started right away.
One of the more frequent questions involves how to get started or how to stay motivated. I can't offer a one-size-fits-all answer (and my personal motivation techniques would take too long to describe), but I would like to point teachers and students to one resource - NaNoWriMo.org (National Novel Writing Month). Yes, in 30 days this organization will help motivate and push you to get that book out. And they have a STUDENT VERSION! If you're a teacher who has some students who are budding writers, put them on to this site... PLEASE!
Is it crazy? Yes. Can it be done? Yes (and I've done it). Take a look at the site and read its FAQ and you might find the motivation to start writing - NXT book or something else. Good luck.
Jan 20, 2008
To me this is a really amazing and inspiring use of the NXT – as an educational & research tool, & well beyond “a simple toy”. I was once asked if an NXT-based rover could function on Mars, and opinioned that I didn’t know, but doubted it: conditions on Mars are sub-freezing, and the atmospheric pressure is only bout 1% Earth sea level, almost a vacuum... certainly not on the list of environments the NXT was designed for. But here is an example of such “consumer electronics” performing under similar conditions, at least for a limited time. Pressure at 100,000 feet (30 km) is roughly 1200 Pascals… or just 1.2% of the sea level pressure. And temperatures in the payloads hover around 0° C (32° F) (they use small internal heaters to keep it that warm). Not too far from roving around on a Martian sand dune.
An amazing accomplishment for the NXT, especially for the students and advisors in the BalloonSat program. Congratulations!
Jan 19, 2008
1. Rich H. has created a MINDSTORMS-specific Google Co-op for searching all things MINDSTORMS - check it out here.
2. Scott, one of the coaches for the Michigan OxfordEnergy FLL team, sent over a link for his team's latest FLL videos and photos - check it out here.
3. Frederik emailed me about his LeJOS-driven tic-tac-toe robot - view the video here.
4. Mindsensors.com has released its beta RCX Sensor multiplexer for NXT - also called the RXMux. RXMux allows you to connect upto 4 RCX style sensors to NXT and its availability should be late February. Read more here.
Jan 18, 2008
Prof. Frank Zimmermann from the Nordakademie polytechnic in Elmshorn, Germany, has published an Eclipse plugin that allows you to graphically model NXT applications based on statemachines and generate code from it that can be run on the brick (based on leJOS NXJ).
Very interesting approach and the only NXT language next to NXT-G (and maybe the VL contained in Microsoft's Robotics Studio) with a graphical syntax.
As an additional (quite helpful debugging) feature, you can even use the diagram to watch the execution of the program on the NXT!
The whole thing can be seen live also on the OOP in Munich next week at Gentleware's booth.
Update: a video of the plugin in action on the OOP can be viewed here.
Jan 17, 2008
I set up a loop to play a high note, 1 second break, low note, 1 second break and to loop until touch sensor is pressed. Once the touch sensor is 'pressed' it will break out of the loop and say goodbye.
Now if I press and release the touch sensor when it is playing the low note, by time it has finished the high note, the touch sensor is no longer pressed and the program loops as expected. To paraphrase, because the touch sensor has not been pressed at the exact time the loop block is checked, it continues to loop. This is exactly I as expected.
However, if I change the the loop condition to look for the sensor being 'bumped' (pressed and released) it doesn't matter when in the loop I press the button, it will remember it and once it checks the loop conditions after the high note, it will exit the loop.
This also works for the NXT buttons as inputs but not any of the other sensors.
Following the directions in the Jake of All Trades blog, I grabbed a battery box, 3.5 mm miniplug, & project enclosure from Radio Shack (the rest of it I had laying about, but still shouldn't set you back more than a couple bucks) and set to work. Trusting the regulator in the headset was good, I risked powering it at 12V DC (risky), so all I needed to do was power both the headset and receiver from the 8 AA batteries (through a switch for ease of use), and wire the video signal from the standard RCA output the receiver provides to the RCA+power miniplug to hook the headset into. I then hooked the battery box to the side of the project enclosure (with 3M Dual Lock), & the whole thing to the back of the receiver (more Dual Lock), and that was it. The result is a nice little B&W head-mounted display that can be stuck in a pocket or clipped to a belt, and allows me to drive around with a "robots eye view" - without needing a TV, or even a laptop & video card. Even for me, this was easy*, and I've not even bothered cracking open the headset unit to switch it to NTSC format (it is set to PAL video by default, & I'd probably get a better image if I performed the hack shown at Jake of All Trades).
Getting the entire "Spy Video Car" (around $100) might actually be a better option for some hackers - I suspect you could gut the RC car and controller for everything you need, already wired together, and just provide the power & case. But since I already had a camera handy, the fact that Wild Planet has just the video headset available ($25 at this time) made it a much cheaper option... not to mention a lot of fun to hack. And that's coming from a guy who is not exactly hacker-friendly (why do you think I like LEGO electronics?).
Now excuse me as I send LNE/Packbot on a search and destroy mission under my bed. I know I has a fresh pair of socks under there somewhere...
*Well, it was "easy" after I figured out I had cross-wired the power and video signals to the headset, and then fought with the stupid soldering iron for 20 minutes trying to undo the work I'd just done... yes, I'm poor at soldering, but not quite as poor as the lousy resoldering job on the miniplug makes it look. And yes, it still seems to work after my mistreatment.
This 'Sale' pops up now and then...but, a little more always helps!
One thing I noticed after making this robot is that controlling it from the keyboard feels like playing a very realistic video game. :P
P.S. Another thing I did with the keyboard function is make a NXT Messenger. I can type a message on my keyboard up in my room and someone can read it two floors down on my NXT display screen. :-)
Jan 16, 2008
Sibrecht Bouwstra, a Dutch student of Industrial Design, has published her design of a "Natural Animation Extension Pack for LEGO® MINDSTORMS":
"My goal was to create an actuator and brick that stimulate natural animation and are useful forAs you can see from the pdf document, Miss Bouwstra manufactured a custom motor that is much more silent than an original NXT motor and her own (flexible) parts from plastic and latex.
the creation of autonomous robots. Therefore, I explored with the creation of flexible bricks and a silent & small motor. The results and a practical documentation on how to create the bricks, can be found in the following link for those who are interested: [link]
I hope this information will be useful to you! A movie of the result can be found on [link] (Click on Gallery and than on the Lego brick.)"
Do not miss this!
Jan 15, 2008
OK, I've not gotten my Sumo video together, but the people in charge of NXTLog have, and it's rather nice. Some of the final rounds have been edited together into a nice video, complete with soundtrack, and are linked to off the MINDSTORMS Special Events page. I've embedded a link to the video above as well. Really, video tells you so much more about how this event went down - including the spectator reactions you can hear in the background, and how interesting or close some of the matches were by the final rounds. The number of "come from behind" wins was a fun surprise, as in some events the winner is a complete runaway, while other times it's not uncommon to have a situation where "robot A" reliably beats "robot B" which reliably beats "robot C", and where "robot C" almost always beats "robot A" as well in a confusing round-about nobody-comes-out-on-top result. Surprising? That's because some strategies work better against some opponents, and there's always a healthy element of luck (although a good design tries to minimize that of course). In the NXTLog sumo event it was a little bit more clear cut, but still very exciting in the final rounds. Take a look at the video, and enjoy!
Jan 13, 2008
Jan 12, 2008
Jan 11, 2008
Jan 10, 2008
Today, LEGO® has announced a partnership with Codatex Hainzlmaier GmbH & Co. KG, of Salzburg, Austria, to develop and market an RFID sensor that will seamlessly integrate into the NXT:
"BILLUND, Denmark, January 10, 2008
The LEGO Group today announced partnership with Codatex Hainzlmaier GmbH & Co. KG, of Salzburg, Austria to allow the manufacture and sale of hardware accessories certified by the LEGO Group for the LEGO® MINDSTORMS® NXT robotics toolset. This partnership represents the continued evolution of the company's commitment to community-driven innovation and open-source development surrounding its next generation robotics system.
The contract between the LEGO Group and Codatex was signed October 21, 2007 at LEGOWorld, an annual gathering of LEGO fans and community members in Europe, where a prototype sensor was demonstrated to attendees.
The third-party licensing agreement gives Codatex Hainzlmaier GmbH & Co. KG access to official LEGO MINDSTORMS NXT sensor housings to develop and market accessory sensors compatible with NXT that are complimentary to the look, style and function of the NXT toolset. Codatex sensors will integrate seamlessly within the NXT software programming environment and are tested to the same high quality and tolerance standards as the LEGO Groups own manufactured products.
RFID, which is short for Radio Frequency Identification, is a leading edge technology used in many industrial and commercial applications, like all kinds of access control, animal identification, supply chain management and many more. The first version of the new RFID Sensor will read 125 kHz transponders. The number stored in the transponders is of 5 byte length allowing a variety of more than 1 trillion combinations.
Within the LEGO MINDSTORMS NXT world the RFID sensor will allow users, for example, to protect their programs, so you can only start it with an individual key transponder. There is also an unlimited flexibility to program different actions upon identification of different transponders.
"We are thrilled to include Codatex as new licensee and look forward to add the RFID sensor to the LEGO MINDSTORMS portfolio of 3rd Party accessories," said Steven Canvin, Marketing Manager for LEGO MINDSTORMS. "We expect to see many new play scenarios evolve around the RFID sensor, which we believe will expand children and adult enthusiasts' ability to build and program robots that do what they want."
"We are very proud to launch the RFID sensor for the MINDSTORMS NXT platform," said Hermann Hainzlmaier of Codatex. "As an accessory to the NXT, we believe that the RFID sensor will open up for many new play experiences for both young and old users, and this is only the beginning, because we have many more ideas for products and accessories to come!"
About Codatex Hainzlmaier
Codatex Hainzlmaier GmbH & Co.KG has experience in RFID since its very beginning in the mid- 80s. With its small team of experts, Codatex has specialized on developing and marketing RFID OEM products for access control and time and attendance equipment.
NOTE: LEGO MINDSTORMS NXT information and product images can be downloaded from www.mindstorms.com/press.
See http://www.codatex.com/ and http://www.legomindstorms.com/ for more information on coming products and details."
UPDATE: Here's some pictures - I'll post a review a little later today. - Jim
FYI: With the Sensor you get two of the transponders seen in the bag in upper left corner of picture. The rest are extra options that I believe will be sold separately - "watch" transponders for wearing on wrist and bags of 10 clear transponders.
Anyone interested in using the NXT in the classroom will enjoy exploring this program at Wichita State University. The education and engineering schools are working together to provide teachers with both the knowledge and the tools to use the NXT productively in their classrooms.
The challenges for the 2008 robotics competition at Wichita State can be found here: http://wichita.edu/shockermindstorms.
If you are a teacher in Kansas, note that there is a significant grant program to support your use of NXT in the classroom. (http://tinyurl.com/32ch7q)
Do you know of another great program? If so, tell us about it.
Jan 9, 2008
The guys from leJOS NXJ, the Open Source Java platform for the NXT, have published the new beta release 0.5.
Prominent changes and new features are:
- Support for Macintosh OSX (USB only so far)
- Support for many third party sensors and adapters
- Greatly improved Bluetooth support including multiple connections and power
- RCX comms using Mindsensors NRLink adapter
- Garbage collector
- Improved Ultrasonic sensor support
- Execution of code from flash
- Automatic defrag of file system
- Remote monitoring and tracing over Bluetooth
- Remote debugging (tracing) over USB
- Faster and more accurate Motor regulation
- Speed improvements
ps. An updated version of the Eclipse plugin for leJOS NXJ will be provided soon.
This hopping frog is from Fay's book, "LEGO MINDSTORMS NXT Z00".
Can you see what Fay has done to make the frog jump and give it forward propulsion? Can you also see what gives it stability and traction? (The frog can be made from one retail kit and a couple of inexpensive, non-LEGO parts).
(P.S. The small human on the left is our son).
Jan 7, 2008
The class was lead by Stefan, who did a wonderful job. There were 6 teams of 2 kids each -- though we could have trained over 20 adults (if they had only been allowed in the class :). The kids had to program an Education robot to drive a pattern on a little riddle; “Das Haus des Nikolaus “ (the home of Santa Claus).
It is a house that you can draw in one single line, without lifting the pen from the paper, or doubling-back any line. (see image).
The kids learned how to code, and debug their own program. Even different languages are no barrier for these kids, there was a Dutch-German team that worked 2.5 hours, great team work! At the end of class each team demonstrated their robot, then I showed a few models from our Idea book. It was a great day.
more images are in this brickshelf folder
Jan 5, 2008
This first robot I made is the usual track-the-ball robot. I wanted to see how well the software's color detection and tracking worked, and I was very satisfied with the result. Although the surroundings need to be controlled (to keep other objects of the same color out), the software does a great job tracking objects. One disadvantage that is very noticeable in this robot, however, is that the Bluetooth communication takes a little while, so the robot doesn't have very good "reaction time". Hence, I had to make it turn slowly so it wouldn't go past the ball before recieving the command to stop.
The below video first shows the robot following the ball from side to side, and then shows it following the ball forwards and backwards. I had some trouble getting it to do both at the same time, and didn't want to take the time to figure it out. :P
(Of course, the article's link will bounce you back here...)
I'd actually recommend looking over the entries of the 29 finalists for at least two reasons. First, there are a wide variety of strategies and building techniques in the list - they're not all perfect (& some of them didn't work, I'm certain, as intended), but there's a lot to learn from other people's designs. Second, these represent some well-documented robots on NXTlog, which was very important in this contest - after all, if the judges couldn't build them, they couldn't test them. And if the program didn't function, they couldn't run them. Testing I suspect was critical, as some of the programs I looked over clearly either hadn't completely understood the rules (no three second delay was a common problem), or hadn't tested the robot (the program, as written, just didn't work).
Some of the robot were remarkably simple, durable, and functional - DozerBot by LEgoFan65536 was a good example, and a lot of us just picked it up and looked at it due to the contstruction (OK, and the fact that it looked kinda "cute"). Some, like Intelligent Sumo by rjbsfarm, were a blast to watch even if they didn't do quite as well as intended (here, Intelligent Sumo did pretty much what it was supposed to, but couldn't run fast enough to avoid some of the more aggressive opponents. It's also a great example of documentation without an LDD file - the pictures were clear, ordered, and made construction possible. I've got some video of it going against Not-So-Blind-Bandit that is just great, I'll try to get some together later. Not-So-Blind-Bandit by poetryinmotion used a novel sound-based system that didn't seem to function perfectly for detecting the opponent, but it was well-tested and stayed on the ring even when it missed its opponent, allowing it to do fairly well (John Brost built this one at home, so it had by far the nicest color scheme of the day, a red-&-NXT-white shell that just made it a nice looking robot overall). And then there were some that while they had a cool weapon, like NXTardigrade nosepuncher sumo, it didn't function well in the ring... but we had a great time retasking it to punch Jay in the nose repeatedly :).
Hopefully some of us or LEGO will be able to pull together the time to put up some video soon. We do have some, it just takes time to edit it... and it's a lot of fun to watch.
Jan 4, 2008
Here is the contest objective described in the simplest terms (taken from the official website):
"To win the Google Lunar X PRIZE, a team must successfully land a privately funded craft on the lunar surface and survive long enough to complete the mission goals of roaming about the lunar surface for at least 500 meters and sending a defined data package, called a “Mooncast”, back to Earth."
So, a few things:
From Ask an Astronomer: The temperature on the moon varies from -387 Fahrenheit (-233 Celsius), at night, to 253 Fahrenheit (123 Celsius) during the day. Because the moon has no atmosphere to block some of the sun's rays or to help trap heat at night, its temperature varies greatly between day and night.
This leads to some questions:
1. At what temp will plastic (specifically, LEGO NXT Technic plastic) shatter?
2. At what temp will rubber shatter?
3. Can the NXT Brick be insulated somehow to protect it from these temps? Does circuitry degrade at these temps?
I think most of us will agree that sending an NXT robot to the Moon's surface is probably a bad idea. But there's a saying that I'm going to modify a bit - "The only difference between the difficult and the impossible is cost."
So, given some funding, how would a dedicated group of LEGO NXT fans go about building a robot that is NXT based that could participate in the Lunar X PRIZE? Cast components out of metal? Insulate the Brick inside some sort of shell?
(Don't take this too seriously, folks... have fun with it and keep the discussion positive)