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.