This mindstorms robot checkers can play checkers against itself, with a person, another robot, or with a computer.
Language: Matlab (robot vision), C (checkers engine), NXC (inverse kinetic done here, could have done in Matlab)
Hardware:
Microsoft webcam
2 motors for x and y (inverse kinetic)
1 motor for linear actuator (low or raise the piece)
1 motor to switch the pneumatics (grab the piece)
1 motor to provide air pressure to the tank
1 NXTMMX mux to control 2 additional motors.
The two sensors are connected facing each other with a shield around them to block out ambient light. Each sensor is connected to a different NXT. One NXT sends data to the other by blinking its light sensor on and off, which the other light sensor picks up. The key advantage I found was that these blinks can be picked up over very short intervals of time (~30 milliseconds). This makes simple communications quite fast - perhaps faster than Bluetooth.
Here's a video demonstrating the "LightComm" cable. One NXT sends the position and power level for the motor to the other NXT, and then both NXTs move their motors accordingly. In the video, the NXT beeps when it starts sending each message, to give you an idea of the speed of the communication link. In the last part, I opened the casing around the light sensors so you can see the blinks.
One advantage of this cable is that you can customize the method of communication to be the most efficient for each application. One method would be to have the light blink on and off like a digital link to send "bits" of information. In the above video, I used an analog method, where the data is sent by the time duration of each blink. The light blinks a total of two times. The first blink gives the target position of the motor, and the second gives the power level. Amazingly, the recieving light sensor can accurately measure the duration of the light to milliseconds! Thus, each millisecond in the duration of the blink represents a degree in the target position or a unit of power. As you can see in the video, the message is usually transmitted with an accuracy of about +/- 2 degrees, which should be ample for most applications.
-Jonathan
Monster Chess went over wonderfully at Brickworld, drawing large crowds, playing multiple games, and winning acclamation & awards. It was so well-liked that LEGO requested it almost immediately... but other venues (such as Makerfaire in Detroit on 31 Jul & 1 Aug, 2010) had also already booked it. With a double-booked tour schedule, what's a Monster Chess set to do?
LEGO was interested enough in having it at some events that they were able to dig up parts to make a copy of this huge creation. But with less than a week, the challenge was to assemble more than 73,000 individual pieces into a single master creation: no easy feat. So when a shipping pallet with 412 pounds of LEGO arrived at Steve Hassenplug's door, he did what came naturally to him: called on his friends. Over the course of the 17 Jul weekend, more than two dozen people* participated in a mass build to restructure the random pieces into another full functional chess set. Slightly under 48 hours later, it build was done. Steve estimates it took roughly 300+ person-hours (we could have done it a little faster, but we did sleep some, and play a game of RoboRally).
er that much better than I can here, and they will be expanding). It's about two other aspects in the LEGO and NXT world: community, and really massive builds. Monster Chess looks impressive as all get out, but for the folks that actually produce things like this, a good bit of the "fun" is in the doing, not the finished product. Getting a bunch of people together to build a copy was an amazing amount of fun. In our case, my son Ben & I walked in about halfway through at 5 PM on Saturday, and asked what we could do - we were handed two large boxes of parts, and one of the original knight pieces, and asked to make four copies (2 white, 2 black). It was a wonderful treat, turning roughly 1300 parts (420 of them pins) into four elegant sculptures while chatting with friends... not to mention the fact that I got to race a 12-year-old
in a speed build of a model that we certainly never had a chance to build before (I won on the knights, but lost on the rooks later that weekend, so we called it a tie). About five hours later, we switched to building four copies of the rooks, which are completely different in structure and design philosophy. Where the knights are graceful, curved, complexly angled constructions, and very organic, the rooks are a sharp contrast: solid & angular, with some parts so amazingly strong and reinforced that Ben had to ask my help to drive the axles into their places, and using reinforced gearing systems to transfer the large torques needed to fire the Zamor sphere launchers built into them. For stress-relieving breaks, we would take "time out" to cover 48x48 baseplates with 2x2 tiles to make the board (with more than 570 tiles on each baseplate and an 8 by 8 board, close to 37,000 tiles had to be applied during this "speed build"). Another group of people formed an assembly line to produce the 32 
identical robot bases that the "shells" sit on to make the completed pieces. 32 NXTs. Almost 100 NXT motors. More than 120 color sensors (and of course the more than 220 wires that were needed to hook all this together, and we've not even begun to talk about the actual LEGO pieces). And through this all, we had fun - talked to new people, reunited with old friends, and learned about others building styles and techniques, as well as just talking with a bunch of people that share a common passion (or obsession).
Huge multi-hundred-pound build opportunities are rare. They've got to be; most of us can't afford anything like enough LEGO to do this sort of thing. But the community aspect... that can be shared by anybody. From 7 to 70, anywhere in the world, you can usually find someone to interact with in the LEGO universe... hopefully in person, but if not, on-line. For some of us, we had to drive a significant distance to participate in this... but it was worth every last minute. If you ever get the chance to do a large build, do it... and even if you don't, find other people to form a community with out there. You won't be sorry, and will learn much more, much faster, than you may have ever dreamed of.
*To those two-dozen-plus folks: a really huge thank you, as this wouldn't have happened without all of your contributions. So let me quickly thank, in no particular order, John, Steve, Heather, Matt, Kurt, Ron, Zoe, Bryan, Kathie, Brian, Ben, Tom P., Chad, Brenda, Steven, Kate, Bunnie, Barbara, Aaron, Stacy, Tom B., Linda, Tom T., Jennifer, James, & David, and a huge thank you to LEGO for providing the parts, & shiping massive amounts of LEGO in a rapid fashion.
The NXTLog Challenge this summer is to build a robotic pet! Real and made up animals are all allowed. Awarded categories will be: Domestic Pets, Exotic Pets, Creative Pets, and Interactive Pets. The deadline is August 31!
Full Disclosure – I am an employee of Microsoft Corporation with an interest in robotics and also am a big fan of Lego Mindstorms and Lego Technics and am patiently waiting for my two young boys to get a bit older so they can discover the fun of building with Lego Technics.
You may have heard that Microsoft has a robotics systems of their own which is now free to download and use at http://www.microsoft.com/
You may have also heard that it also comes with a simulator so that you can simulate robotics in many different simulated environments such as a house, factory and city. Recently we have ran competitions where contestants were required to drive a simulated Mars rover and drive a car through a simulated city whilst obeying all the rules of the road.
However did you know that since its initial release Microsoft Robotics Developer Studio has supported Lego Mindstorms? Yes its true, you can build robotic applications for your favorite Lego robot with a freely available development system from Microsoft built on .NET.
Ahaa I hear you say, I have to be a C# developer before I can use this system. I have just bought my new Lego Mindstorms kit from the Lego store and now you want me to learn a new development language?
Well actually the Microsoft Robotics Developer Studio team has made it easy to build robotics applications for Lego Mindstorms and you do not have to write a single line of code. The tool I am talking about is Visual Programming Language. With this tool you basically drag activities and services onto a page and link them together. Think of activities as commands like IF something happens and Services as talking to hardware such as a Lego Mindstorms motor for example or a compass. We have services for motors, sensors from both Lego and Hitechnic and more. In no time at all you will have built your first Lego Mindstorms robotic application using Microsoft Robotics Developer Studio and with no coding required.
However if you decide you want to get into .NET programming with C# you can look at the source code behind your new robotic application. Just rest assured that the decision is yours to either stay in the visual programming world with Microsoft VPL or delve deeper and work with the generated code.
One question we always get asked is where does my robotic program run? With many tools for writing applications for the Lego Mindstorms robot the final program is downloaded to the robot directly. Microsoft Robotics is a .NET system so requires a Windows based PC. This means your program runs on your home computer for example and talks to the Lego Mindstorms robot either over USB or Bluetooth. While some hobbyists may see this as a limitation there is actually a huge positive to the story. Let’s assume you keep working with your Lego Mindstorms robot but then start wondering what it would be like to control a larger robot that costs many thousands of dollars. Well for most of us there is no way to do this. However with Microsoft Robotics Developer Studio we even give you a simulated environment with simulated robots including a simulated Lego Mindstorms robot. So as your skills grow you can test them out on larger, more expensive robots without buying them. Microsoft Robotics Developer Studio lets your skills grow from being a hobbyist to a professional in the future world of robotics. In addition because the brain of your robot is running on a PC you can write much larger and sophisticated programs.
You can find more about Microsoft Robotics at this location and here is a screen showing what a Visual Programming Language application for Lego Mindstorms looks like.
Thanks for reading and you can learn more about Microsoft Robotics by watching this video - http://channel9.msdn.com/
