Back when we had two incomes, no mortgage, and no kids, I found it scarily easy to succumb to the attraction of the original Lego Robotics Invention System. It was quite the achievement at the time: two motors, a bunch of basic sensors, and a whole heap of Technics. The software was barely stable, but if you worked at it you could create a line-following robot or perhaps a humanoid that could take a couple of steps before toppling over.
Since then, Lego have revised their robotics kit completely with the original NXT, and are now set to release the Lego Mindstorms NXT 2.0 kit. The kit will be available in New Zealand from September, with a retail price of $499, unless you can grab it in a Toyworld sale. So what do you get for your money?
- The NXT 2.0 “brick”. This is the nerve-center of the kit. A chunky brick that takes 6 AA batteries. It has three motor outputs and four sensor inputs. It connects to your PC via USB or Bluetooth to receive program updates, and can talk to other NXT bricks via Bluetooth too.
- The NXT 2.0 software for your PC or Mac. This is what you’ll use to program your NXT brick. Don’t think of it as esoteric code with FOR loops and semicolons. Everything is done via drag-and-drop. Blocks for turning motors on and off, sensing colour, and playing sounds all slot together as easily as physical Lego blocks.
- Three honest-to-goodness servomotors (I’m not positive, but I don’t believe they are stepper motors – can anyone inform me otherwise?). In the old days you had to turn the motors on for a predetermined time, and just pray that they ran at the right speed for the right number of rotations. The NXT kits use feedback to determine how far the motor has turned, so you can command them to turn 90 degrees, or 4 rotations, and they’ll do just that (or churn through batteries trying to).
- Two touch sensors – just basic momentary switches as far as I can tell.
- One ultrasonic distance sensor, designed to look uncannily like a pair of robot eyes.
- One colour sensor (including a tri-colour LED lamp). This was the only real issue I had with the kit: the colour sensor didn’t work so well in bright sunlight. It worked fine at night or indoors in the shade.
- A metric vatload of technics parts. I’m not going to list them all here, but serious Lego geeks can check out a comparison of NXT 2.0 parts vs the previous version, or a complete breakdown of parts in the kit.
Those last two links may give you a tiny peek into the world of Lego geekery on the internet. Just like everything else, it has been taken too far in some places. Lugnet and Peeron are just two of the many of sites dedicated to documenting Lego kit contents. Mindstorms also has its own dedicated following, with blogs, project sites, and even the official Lego Mindstorms Community site.
The enthusiasm around Mindstorms NXT is well-founded. You can get months of fantastic fun from the basic kit, building and modifying the included robots. These include:
- Alpha Rex: the humanoid bot that can walk, dance, open and close his hands, and detect colour.
- Shooterbot: a tracked robot with a good grunty ball shooter.
- Robogator: a alligator-esque bot that will lunge at you and snap viciously.
- Color sorter: a mechanism that will sort coloured balls into different locations.
There is a good run-through of these kit bots over at TheNXTStep blog. When you consider that any one of these bots would itself be a fairly expensive technics set, the cost of the overall set starts to make a bit more sense. And once you’ve exhausted the opportunities from the kit bots, there are plenty of parts to build some fairly zany creations. The Mindstorms Community have regular challenges to stretch your imagination, and there is even a worldwide competitive robot league for kids aged 9-14.
Of course there’s nothing stopping you digging out additional technics sets and components and really going to town with your own creations. And then, if you get bored by that, there are companies dedicated to producing all sorts of third-party sensors for the NXT platform. Fancy measuring dissolved oxygen? How about exact digital compass heading?
Additionally, if you find that the Mindstorms programming interface is not keeping up with your expectations or abilities, you’re almost guaranteed to find a language you like. In fact, the Mindstorms NXT kit is a nice way to educate kids (and adults) in basic programming concepts. If they want to take it further, then one of those third-party language extensions is the next step. If you fancy yourself a real hacker, Lego embrace the modding community through an open source program.
Once you see just how far you can go with Mindstorms NXT, you start to understand that this is not your regular Lego set. A bit like a more refined Arduino, this is a platform for building electronic interactive objects. It just happens to be wrapped in Lego compatible connections and Lego branding.
Conclusion: bloody brilliant!