Jan 31, 2007
Frequently I get asked where to find building instructions for NXT robots in the web (and in particular, for such that can be built with a single NXT kit).
Well, one location I know of (in addition to the two ones on the official LEGO page; NXTLOG has a huge collection of robots, but for almost none instructions are available) is my own site - yet, there certainly are other ones. But where?
Would be nice to compile a list of such pages.
If you know of stuff the likes of that, please tell us.
Jan 30, 2007
It was a big event, and everyone had a great time!
We also have our team website up at: http://www.teambuiltontherock.org.
You can take a look at it here - the URL is http://gelisimrobotkulubu.blogspot.com
Thank you, Ömer Şiar Baysal, for the link.
I'm teaching an undergraduate course in the design program at the University of Washington this term that is using robotics in a multi-disciplinary environment. The course employs Mindstorms (using both Robolab and NXT-G, on Macs and PCs) to introduce designers to the world of technology systems, basic programming, and collaborative projects. We have students from visual communication design, computer science, technical communications, and experimental digital art programs working together in the class. It's called Designing Behaviors.
We won't see the results of their projects until March, but it's fun so far. The UW student newspaper (The Daily) just did a little story on the course that might be of interest to other educators. I'd be happy to hear from anyone else doing similar kinds of things.
Jan 29, 2007
I had a significant number of requests for more information on my LEGO PackBot implementation, so I pulled together some more information. First, I took it all apart and documented the process with a series of 15 images ("lnebuild1" through "lnebuild15" in my Brickshelf Folder). Take a close look (in one step, pieces apparently change color; it's just something I did to highlight the pins you needed to pull), and you might be able to reproduce it. You will need at least one extra studless turntable and six of the new treads, plus I'm sure other studless pieces. In rebuilding it I was able to reinforce the structure some more, add the US sensor and a HiTechnic accelerometer, as well as place the minifig driver in a much safer spot.
I also put together a better video of unit LNE in action, (embedded below, hopefully) showing it climbing slopes, crossing gaps, "swimming" in packing peanuts, etc... as well as a couple more "interesting" activities. Let me know what you thought of the video - I've not edited together a lot of videos like this, so be gentle :-).
Jan 28, 2007
(NOTE: Volume I of this curriculum teaches students to apply measurement and geometry to the NXT. It is not covered in this review).
This is a complete curriculum for teaching students about NXT hardware and software. (NXT-G is the only programming language covered).
The curriculum teaches students to build three different NXT models, to program them to do different tasks and to reflect on their experiences. The three models are a caliper, a guard dog and a mining robot that investigates tunnels. Lesson plans for teachers are included.
*Outstanding instructional videos for teaching students to build and program. (The videos are flash files playable in any web browser).
*Detailed worksheets for student reflection
*A wide range of programming levels are covered, from beginning to advanced.
*The price: $225.00
*Some of the worksheets and powerpoints use technical language beyond the range of some young students. (These, of course, can be reworked by teachers).
The curriculum is available from the Robotics Store: store.robomatter.com
TEACHERS: Let us know if you have used this curriculum and what your experience has been. And feel free to post questions if you'd like more details about the curriculum.
Jan 27, 2007
I've received requests for chapter excerpts for my book "LEGO Mindstorms NXT: The Mayan Adventure" and I'm happy to comply.
Below are links to numerous items, including the Design Journal Page that is used in the theory chapters (chapters 2, 6, 10, 14, and 18) to help develop the 5 robots included with the book (and useful for helping design your own robots).
The Design Journal Page is all yours - make as many copies as you like. The PDF file contains 6 blanks for you to print out and I hope you find it useful. If you're not sure how the Design Journal Page works, be sure to check out the Chapter 2 excerpt below - each section of the Design Journal page is covered in detail in those theory chapters (mentioned above) and by the time the reader has completed all 5 robots, the Design Journal Page will be very familiar territory.
Click here to download Chapter 1 and Chapter 2 - The fictional storyline starts (Ch1) and Theory Chapter with Design Journal Page (2)
Click here to download an excerpt of Chapter 3 - Building Instructions for a robot
Click here to download an excerpt of Chapter 4 - Programming Instructions for a robot
Click here to download the Design Journal Page
Click here for bundled excerpts of Chapters 2, 3, and 4
and finally click here to download the Table of Contents
Jan 25, 2007
"I am teaching a group of students immgrating from the RCX to NXT. We have been working on buidling a line follower using the NXT set.
We have decided to use the robolab 2.9 program to work on this project as they are more familiar with robolab software.
Would appreciate it if you could help to point us in the right direction with regards to the following:
1) How do I calibrate the NXT light sensors? I understand that the NXT-G software has a calibration function but not the robolab 2.9 software. There is no calibration file in the NXT brick as well so we can't use that.
2) Can 2 NXT light sensors be used to build a line follower robot? How different would the program be via-a vis using a single light sensor?
Thanks for the help."
Jan 24, 2007
If you're not a subscriber to ROBOT Magazine, you might have missed a great article in the latest issue on "Teaching with Robotics" - fortunately, ROBOT Magazine has posted the article (with some extra content) on their website for all to read.
Not only is the article very informative, but it's got a TON of reference links... this article might make a great addition to a proposal to a school (or school board) for funding a robotics program.
Take a look at the article here - if you find it of interest, be sure to send the editor, Tom Atwood, an email and thank him for making the article available to the public for free...
Jan 23, 2007
With the NXT I had a much better start: higher-torque motors with more control, as well as a studless system that encouraged connections that would not come apart easily. After a couple days, I came up with Unit LNE (LEGO NXT Explorer) of the Dinochrome Brigade (10 pts if you catch the reference ;-). Based on the PackBot design, it can climb a steep slope (30° or more), scale mountains of dirty laundry (or RCXs, or minifigs), and climb up steps taller than the robot itself. It can also flip itself back upright if it finds itself upside down (an accelerometer from HiTechnic is very handy in this regard). The first hurdle was getting one motor to drive both the belly treads and the flipper arm tread on one side, while still allowing the "shoulder" to freely rotate 360°+. The harder part was actually making the structure strong enough to take the resulting loads and torques without twisting apart.
Sometimes looking at the world around you can give you some very challenging ideas for a robot. LEGO is "just a toy", but as an engineering tool it can be used to model some very impressive creations... but of course, I probably don't need to tell readers of this blog that :-).
More images can be found in my Brickshelf folder as well.
Brian "Bolo" Davis
The Lego NXT Direct Commands required to poll the sensor were almost identical to the accelerometer. The Mindsensors datasheet identified which I2C command codes and memory addresses to use, and they just so happened to be the same as the accelerometer part. I did not need to calibrate the compass, and was able to get readings from it right away. I was impressed with how accurate it is, even when using an 8 bit value. ( default 10 bit values ) I was able to poll the compass every 40ms with no problems whatsoever.
Using the compass together with sonar and wheel encoder values should make it possible to have the NXT perform more advanced autonomous behaviours such as navigation and mapping. I would be interested to find out if any users have had success in getting the NXT to autonomously navigate itself around an real world environment, such as an office floor, without getting stuck?
Note: I have heard from a few users who have not checked out the Lego NXT Direct Commands yet, so I'll post some quick examples in a few days. The Commands are supported natively by the Lego firmware, and can be sent to the NXT over Bluetooth from external programs like my roboDNA Dashboards. It allows you to control the motor speeds, and obtain sensor values for telemetry. Details are in a PDF file found in the Lego Bluetooth Communication Guide: http://robodna.com/roboDNA/downloads/NXTDirectcommands.pdf
Great idea, Philo! I always wondered if someone would do something like this.
Jan 22, 2007
1. A noticeable lack of using sensors - I would estimate that 75% of the robots I saw did NOT use sensors, other than the built-in rotation sensor on NXT bots and encoding/rotation sensors on RCX bots. The Light sensor was the most frequently used with the Touch sensor coming in 2nd... what I found interesting was that most of the bots programs were pretty much 90% or more MOVE blocks and all movement was based on table positioning and lining up the robots (either using jigs or aiming visually).
2. Aiming - as mentioned earlier, most robots (probably 80% or more) were aimed using a visual point-and-aim method. Interestingly, when asked about the lack of consistency in test runs and competition runs, most teams admitted that their aim was off and very few indicated that using a jig was an option (or other fixed/sturdy object useful for placing the bot in the exact same spot every time).
3. Confusion over turning rates - many of the teams indicated that they switched to "rotation" movements instead of degrees because they couldn't figure out why their robots would be programmed to turn 90 degrees but would typically only turn 40-50 degrees. This told me that there's still not a good understanding (either by students or teachers/coaches) of how a wheel-circumference turn and a motor rotation are not 1:1. Most teams that answered this question about their design seemed to think that programming one wheel to turn 90 degrees in a forward direction and another wheel to turn 90 degrees in a reverse direction would result in the robot spinning in place 90 degrees and were surprised when this wasn't the case- TEACHERS/COACHES PLEASE LISTEN: it is VERY important for students to learn to program using degrees. Using time isn't a good option because it is so easily affected by battery power and rotational movement programming is okay, but it's probably debatable if the accuracy is the same as with using degrees.
4. Teamwork - one of my questions that I liked to ask was this: "If I were to pick one of the team members at random and ask him/her to run the robot on every challenge, would that person be able to do so?" - I was basically trying to find out how many of the team members were cross-trained - many of the teams consisted of individuals who ONLY knew about the physical robot, some ONLY knew about the research portion, and others ONLY focused on the programming. While this is probably typical considering time constraints and interest amongst students, I cannot imagine that any team will benefit from not knowing a little of every aspect of the competition. It's just my opinion, but I think that any student participating in the FLL challenge should have an opportunity to contribute to robot design, robot programming, and the research portion. We all tend to focus on our strengths, but coaches and teachers need to encourage those students who might tend to "blend into the background" and get them more involved.
5. Programming - I would sometimes encounter a team where only 1 or 2 was handling the programming. They typically would do all the talking and were very good at describing their work. But when asked if they had cross-trained their team and demonstrated the program in its entirety so the entire team understood the programs, most of them were at a loss for words. I asked one team where the SOLE programmer had all the information what would have happened if that member were sick or stuck in traffic and couldn't make it? Keep in mind that we did NOT allow the coaches/teachers into the Technical presentation. Teachers/Coaches need to make certain that ALL the team members have at least a cursory knowledge of the programming environment - even better, having every team member trained on each program and able to EXPLAIN how each program works is even more impressive.
6. Tactical Planning - Only seen in a couple of teams, I was overly impressed by some teams that had done a sort of comparision on which challenges they wished to attempt compared to points awarded. Some teams were able to explain clearly their reasons for NOT attempting a challenge OR for leaving a challenge for last (typically, not enough points to go after since time was limited). Other teams were able to combine challenges in a way that I hadn't seen before - when asked, they also were able to explain WHY they chose the path/route they did - very impressive. Some teams were SO FOCUSED on doing all the challenges and then couldn't complete 25% of them successfully!!! One team in particular had worked on combing 3 of the hardest (IMO) challenges in one run and were able to nail it almost EVERY TIME!
I had a great time - met some GREAT teams and coaches and saw some extremely well-designed robots. I saw professionalism, sharing, courtesy, and respect exhibited. I hope all the teams had a great time. I'm hoping they're seeing how working on a team can be fun. I also hope they see that math and science can be interesting and challenging and rewarding.
Lastly, I need to say hello to some teams that I met and spoke with - Nifty Muffins of Doom, Girls in Black, RoboChiefs, and Radioactive SPAM - I hope all of you had a GREAT TIME!
Jan 21, 2007
I just developed a really useful and user friendly library to allow NXC users to
use Bluetooth functionalities without problems (and I assure you, for a common user or a child, are huge problems!)
The library is called NXC BTlib and can be downloaded here.
This "how-to" article chronicles Nat's efforts to teach kids to program using NXT-G (and other software). The article includes comments from teachers re: methods they use to teach kids programming. Read the article
Teachers: besides the obvious (e.g, FLL), what languages and methods do you use to instill a love of programming in kids?
Jan 20, 2007
Jan 19, 2007
It was great fun to use an other NXT as a remote and try to put the ball in the goal.
I had programmed the keeper so that it would come out the goal when it saw an opponent, defending like in real live. For more pictures look here:
While adding this, I saw this nice robot, Built by Laurens200, he has also built a walker and more RCX models, looking forward to see more from his creative mind...
Somehow that robot did remind me of a very old one, back in 1986. it used the old 4.5v motors and a wired PC-interface, this was about the time that I started with computer based LEGO.
Nice work Laurens200
Jan 18, 2007
Then on Friday evening Jeroen and I repaired the workshop by creating 4 Tribots.
We took the grippers and sensors of and kept them aside then we created 3 boxes each containing all the parts needed to build 1 base Tribot.
Saturday 13 January 2007 I started with a demo of my new NXT model that I build for our NXTSTEP book and with the remote controlled NXT truck. The kids loved it.
Then it was time for them to build and program. I setup 3 laptops and divided the group of 12 in smaller groups of 2 kids. 6 of them started to build the model and 6 others started to learn NXT-G and program the base steps. After half an hour I switched the groups.
I was amazed by the speed. Within my two hour time frame the kids managed to build and program all the Tribot steps (even the last locate the ball).
The kids did not want to go home anymore.
see this link for the other pictures.
Steve Hassenplug has tried to collect as much information as possible about the (many!) programming options availible so far for the NXT, and put up a nice comparision table. He's gotten input from a number of us on this, although some cells in the table still need to be filled out or updated (for instance, we're still trying to figure out the "best" way to compare and contrast the speed of the different offerings). If you can think of something else to add to this, please feel free to comment here and I'll try to get the suggestions to Steve. Notice that this table already lists 9 different options for the NXT, less than a year after its release... and that's not including off-brick remote-control type applications a yet! Impressive growth. Anybody want to comment?
Jan 17, 2007
Now everyone will be able to explain to non-technical people what SOA is henceforth (and moreover, why LEGO in fact isn't a toy (only)) ;-)
Well, I guess now we actually have to write this thing...
Kidding... the team is probably over 50% completed on the book - we have a mid-to-late February deadline to meet and the listing states it'll be available June 1st! Yikes. I've still got a little more to do... back to work.
(The picture is wrong, too - the title is "The Lego Mindstorms NXT Idea Book: Design, Invent, and Build" and this cover will most likely change... )
Jan 16, 2007
It's just starting up, but watch this site for future updates and developments. As it stands pbLua (a version of the Lua language targetted to the NXT) is still being fleshed out, but Ralph Hemple (one of the original four MUP members) has really made a nice start at a neat and clean language for the NXT. Take a look at the web page - Ralph even has a code example up (written originally by Steve Hassenplug) so you can see what a little line following routine looks like in pbLua. Personally, this is a new firmware I've been looking forward to for some time, ever since I heard it was being developed. Lua just... seems like an ideal language for this sort of thing. I've not tried it yet (I need to work out the install under OSX), but it looks good. Can anyone else out there speak up about experiences with Lua, and how you think it should port to the NXT?
Jan 15, 2007
This is a gearless steering mechanism found in Yoshihito's book, "Lego Mindstorms NXT".
The steering mechanism has its limitations; for example, it can only steer in one direction. (The steering direction can be changed by moving the "swivel" pin to another point on the chassis). Despite its limitations, it's a good model for students and persons new to the NXT.
Jan 14, 2007
First, I looked up what Lego NXT Direct Commands were needed to read the sensor's values over I2C. I checked the Mindsensors datasheet to determine what I2C command codes and memory addresses to use. Reading single axis registers worked well, however, when I started polling the sensor at 40ms intervals, NXT was timing out. It appears the NXT uses a software driven I2C, and there were some issues with glitches being introduced. I can confirm this has been fixed in Lego NXT's version 1.04 firmware released a couple of weeks ago. Downloading and installing the new NXT firmware fixed the problem for me, so anyone building home-brew I2C sensors should try the upgrade!
The colors and other properties can be edited, but here are the pitch and roll gauges I ended up with and included in the sample roboDNA Lego NXT dashboard:
My publisher has posted Chapter 1 of "The Mayan Adventure" on their website. This chapter opens the fictional storyline that continues throughout the book (in chapters 1, 5, 9, 13, 17, and concludes in 21). I've had some people ask for a sample chapter or 2, so I hope this helps. I'm going to try and see if they will print some excerpts from chapter 2 (Theory chapter), chapter 3 (Building instructions) and chapter 4 (Programming chapter).
You can download the PDF file for Chapter 1 here.
Jan 13, 2007
Using the Lego Mindstorms™ system, build an autonomous robot and teach it to navigate an obstacle course and interact with other robots and kids. Follow your curiosity to learn mechanical design basics, computer logic and other abstract skills you don't normally use in everyday life. Working in small teams of two or three, students focus on areas of personal preference and collaborate on solving problems. Offered session 1 only. The class is five-weeks long and meets on Sundays at the South Campus from 1-4 pm. Salary: $25/hour Spring term dates: Sunday, Feb. 4 to Sunday, March 4.
If interested, please contact Paula Goodman, Director K-12 Programs (626) 396-2347 (626) 396-4219 (FAX) email@example.com "
The Color Sensor is now ready and available... you can purchase it either from HiTechnic or LEGO.
You can also download the Color Sensor's NXT-G block from their website by clicking here as well as the block for their Compass Sensor.
Jan 11, 2007
Look at this 7 minutes long video of an impressive car factory build in Germay.
knusel111 (a 31 year old teacher) built together with several 14 to 17 year old schoolkids of the robotik group of the VHG, a German grammar school in lower Bavaria a working car factory. It took them about 1 year to build. The machine weighs around 25 KG and holds 10 RCX units and 50 motors. The 2000 parts will have an estimated cost of 3000 Euros.
He says: "I'm sorry the factory doesn't exist any more. We had to destroy it , because we needed the bricks for our new project. I have to admit I was astonished by the great interest. If I had known that, I would have made better and more videos. Also Youtube has a 100MB limit, I'm sorry for the low quality. The original version has 1,6GB ".
Gerrit and I built something similar back in 2003, but unfortunately didn't have a video camera at the time to capture our achievement on tape. Here are some photos that we took, however.
Brickshelf the factory
Brickshelf the total line-up
This is realy Fantastic, a real show of what Mindstorms is capable of, and with the new NXT, even more.
The above design is found in the book, "Lego Mindstorms NXT", by Yoshihito Isogawa. Others have created "inchworms", but Yoshihito's inchworm design is unique for its creativity and efficiency.
As seen in the above close-up, Yoshihito has used a rubber band and NXT parts to create a locking mechanism for both rear and front wheels. This locking mechanism engages and disengages as the worm moves forward, resulting in smooth movement with a minimum of motor thrust.
I know many people have been awaiting this big step forwards from iCommand. (Which runs a Java program on your PC to remotely control the NXT.)
Details from the leJOS home page:
leJOS NXJ is ready for download. leJOS NXJ is a full firmware replacement and works for Windows and Linux. This is a technology preview of things to come. At the moment there is no Bluetooth, I2C (Ultrasonic sensor), or sound support and we do not have a basic menu system. You can write Java programs and upload them to the NXT brick via USB. (see readme for more information)
Congratulations to Brian Bagnall and everyone who has been working on this, and thanks for letting us know about the release.
Please leave a comment if you try it. (I have not installed it yet, and I probably will not have the time before the weekend.)
- Tony N
Jan 10, 2007
I thought the idea of the robot bringing up the sign instead of displaying text on it's display was a pretty neat idea.
Jan 9, 2007
Well, it looks like iRobot is getting into the robot building arena - a recent announcement from this year's CES shows that iRobot will be releasing a new robot called Create, similar in shape to the iRoomba but with the vacuum attachments (brushes and fluid container) removed. Users will be able to connect devices like cameras and robotic arms - some purchasable from iRobot and others probably home-brew.
Not much more news yet, and I post this only because I think we all see that the home robotics field is growing fast and everyone wants to get in... maybe if enough of us request it, they'll include BlueTooth so our NXT bots can interact with the iRobot device.
Steve at HiTechnic was kind enough to send me the beta block for the new Color Sensor. I was able to import it with no problems and tested the data wires and they worked, too. I've labeled the data plugs in the image - as you can see, you can set a range using the A and B import data plugs and the block will also provide output of a color with Red, Blue, and Green values, each individually available as an output data plug.
The Compare drop-down menu offers "Inside Range" and "Outside Range" options and you can either set values for A and B manually or by dragging the small bars, with A having minimum low value of 0 and B having a maximum upper value of 17.
Okay, readers - what kinds of uses can you think of for the Color Sensor?
Jan 8, 2007
Like many of you, I've been brought up on Lego, and own the RCX and NXT robots.
My work has involved robotics related programing, networking and electronics, but I spend most of my time writing code to remotely operate and run telemetry for Microchip's PIC microcontrollers as well as the Lego NXT.
Some of you may be familiar with the roboDNA Lego NXT PC Dashboard I'm currently working on, and made available for download a couple of months ago. If anyone needs help setting up a dashboard for their bots, just send me an email!
One of my current projects is with the Lego NXT RoboDome here in Ottawa Canada. RoboDome is a fun-filled Lego NXT themed classroom that offers elementary students a chance to design, program and have competitions using a dozen NXT robots. The theme includes everything from Lego specific colors, part bins and cabinets, and even desks designed for Lego building. The RoboDome project was initiated by Jim Dale and Janis Kam at the Ottawa Carleton Catholic School Board back in 1999 for the Lego RCX, and they have recently finished upgrading everything to NXT. They have asked me to help setup 2 RoboDome classrooms with the roboDNA Dashboard software, and I will soon post more details for educators who may be interested.
I have recently been testing a few different Lego NXT parts, including Mindsensor's compass, accelerometer and pressure sensor. I'll be posting my findings soon, and will also add a sample dashboard for these so others can try.
Jan 7, 2007
Jan 6, 2007
Watch the video here.
Jan 5, 2007
The Washington Research Foundation administers patents relating to research done at the University of Washington. Just before Christmas the Foundation filed suit against Nokia, Samsung and Panasonic (Matsushita) saying that they had sold & imported infringing technology.
The companies involved all use Bluetooth chips from Cambridge Silicon Radio (CSR). Lego also uses CSR Bluetooth chips in the Lego NXT. Lego is unlikely to be directly involved the court case at any point, (the number of Bluetooth devices it has sold are relatively small), but may be affected by the outcome.
Over 1 billion (1000 000 000) Bluetooth devices have been sold and CSR is considered to have over 50% of the market. Rival Bluetooth chipset maker Broadcom has reportedly licensed the Washington Research Foundation patents.
Happy New Year to all Lego NXT fans from Cambridge, UK.
- Tony N
Jan 3, 2007
"My daughter (who is two and a half years old) loves to play with Legos (both Duplo and NXT) and she was next to me the 3 days we were building this.
Of course the whole thing can be 100% automated, I just want it for my daughter to play with it, so I used the PSP-Nx sensor from mindsensors so she could move the lift up and down with a PS2 control."
Thanks for sending, Mauricio... I'm sure your daughter loved it.
Well, The NXT Step had a great 2006... we ended the year with over 36,000 visitors - a total of 17,928 of those visitors were unique and from 109 countries.
Thank you ALL for your continued support of our blog and for your emails, questions, and comments. Now that many more of you have received an NXT, we anticipate seeing a lot more innovation from our readers as well as receiving a lot more questions and comments.
It's now been a year since this blog was started... time moves fast. Many of the contributors here are still participating in the LEGO MCP (Mindstorms Community Partners) program and we hope to keep you informed and up-to-date on what's going on, both at LEGO and elsewhere.
Have a great 2007!
The new NXT book that we, The NXT Step blogger team, have been working on is in full-swing. We can't comment (yet) on any specific robots that will be included in the book (there will be 9 of them with full building instructions and programming steps in a CAD format), but there will also be 9+ chapters from various blog contributors on different topics that readers might find of interest.
My chapter is on debugging and includes some tips on troubleshooting your NXT-G programs. Many of these will come as no surprise to experienced programmers, but newcomers to NXT-G (and programming, in general) will hopefully find some helpful stuff in there for helping with pesky programs.
We're working hard on this book - no expected due date yet, but it won't be too long. Some of my fellow contributors might chime in and give some hints about their book material, too. There are some things we can't talk about yet (such as the robots) but we'll answer the questions we can if you've got them...
I hope everyone had a safe and Happy New Year - now it's back to work!