Review: Lego Mindstorms NXT lets you design, build, and program robots… with claws!

Photo by Michael Trei

I've always found building stuff to be incredibly satisfying. Whether it's a something I've hauled home from Ikea, or just a ham and swiss on rye, there's always just a little sense of achievement that makes me feel good. Back when I was six it was Lego blocks, but even the most awesome Lego creations like airplanes and cars would move only if they were propelled by my one-kid power drive system, me. Unfortunately, pushing your toys around just won't cut it anymore for anyone who's been raised on a diet of high-action videogames, so a few years back Lego introduced a robotics system called Mindstorms RIS that let you bring your Lego creations to life. After downloading a set of operations from your computer to the RCX controller, the RCX would then control the various motors and sensors to make your robot perform various simple tasks. This was all great fun, but now the system has finally received a long-deserved update with the arrival of Mindstorms NXT.

When it comes to indoor activities for older kids, or even adult kids with a little spare time, it seems like a lot of them these days tend to involve a computer. What's great about Mindstorms NXT is that it lets you use those computer-savvy fingers to develop a project, and then transfer it into a hands-on practical functioning robot of your own design and construction. Lego suggests a starting age of 10, but it would take a pretty focused and detail-oriented ten year old to figure out some of the subtleties of putting the component parts together. The software used to create all but the most basic control programs did seem needlessly complex at times to my own middle-aged brain, but then I'm sure most 12 year olds will find the programming part to be a piece of cake.

I, Robot Master
The manual includes a couple of relatively simple projects to get you started, and I would suggest starting here to get your feet wet, while learning how all of the different constructional and programming functions work together. Once you've covered the basics, you'll find that there's a wealth of online communities and websites to help you explore the limits of what can be done. Third-party suppliers are also starting to pop up with alternate sensors and other hardware for the system. One nice new feature is NXT's Bluetooth capability, which not only makes for a nifty way to upload your control programs wirelessly, but also makes it possible to control your robot directly with a Bluetooth-capable PDA or cell phone.

I built a basic three-wheeled vehicle that Lego calls a TriBot, then added a set of grabber arms to pick up a ball on command, move it to a different spot, and release it. Because this was a test piece to check out the different components, I added an ultrasonic sensor to allow it to "see" the ball, a bumper that would push the touch sensor to stop the robot if it encountered an obstacle, a light sensor so that the robot would stop on a specific line to release the ball, and a sound sensor to hear the clap that would tell it to pick up the ball.

Putting it all together involved lots of sifting through hundreds of tiny parts, many of which are quite similar to each other, and taking extra care to ensure that you assemble them in exactly the right position and orientation. All of the details needed are there in the instructions if you study them carefully, but if you find building Ikea furniture to be a challenge, NXT robot assembly might drive you to drink. Once you have the physical robot built, the next step is to create the program and then download it to the NXT controller. The programming interface lets you graphically string together a series of commands, with a number of options determining exactly how each command is carried out. The scope for customization is pretty mind numbing, but it's easy to keep things simple until you get the hang of things.

Finally, the moment of truth arrives when you put your creation down on the test pad and let it rip. I found I needed to tweak some of the sensor adjustments a bit, but on about the third try, bingo!

The Raw Bot
In addition to the NXT controller, the kit gives you three precision motors, along with sensors for light, sound, ultrasound, and touch to act as your robot's eyes, ears, and fingers as it finds its way around. You also get a whole slew of Lego Technic pieces (571 in total) to create your robot, including various wheels, claws and cogs, and you can even expand your options further with any number of compatible standard Lego pieces. I was particularly impressed by the precision with which even the tiniest pieces went together.

The NXT brick runs off of six AA batteries and has a built-in display that lets you to set up basic operations. An integrated speaker allows you to give your creation some suitably robotic sounds. All of the cabling and software you need to get up and running is included — all you have to provide is a compatible Mac or PC.

At the End of the Day…
While the Lego name might lead you to conclude that the Mindstorms NXT system is little more than a toy, in truth it's far more than that. The prior generation of Mindstorms inspired a highly dedicated community of (mostly adult) users that stretched the possibilities of the system, and Lego went to them for help in developing this new version. The upshot is that the new NXT is vastly better sorted and more capable than the old system, although less-than-expert users like myself without a handy 12 year old to assist, might find it all just a bit daunting at times. Assembling a cool robot required some pretty intense concentration, but the childlike sense of accomplishment I got once the final result was working was definitely worth the effort.