• Building
• Programming
• Computer-aided design
• Online communities
• Competitions

There are, of course, other aspects that I could have listed here, but these main ones will reveal the enormous potential of the set and, hopefully, pique your interest in creating your own NXT robots.

Realize, however, that I first bought a MINDSTORMS set "just to see what it's like," and years later I'm still surrounded by robots. You've been warned. Now let's start with the first item on our list: building.

Building
The NXT set includes nearly 600 LEGO pieces, but don't expect to see any of the LEGO bricks you played with as a kid. First, you'll find a selection of electronic parts. Chief among them is a programmable microcomputer simply called the "NXT", shown in Figure B.

FIGURE B

The NXT is a LEGO microcomputer. Click picture for a larger image.

The NXT controls the other electronic components. The servo motors, shown in Figure C, use built-in rotation sensors or "tachometers" to measure rotation. They power your creations.

FIGURE C

The servo motor powers NXT creations. Click picture for a larger image.

Sensors, shown in Figure D, include a touch sensor, a light sensor, a sound sensor, and an ultrasonic sensor, used to measure distance.

FIGURE D

The touch, light, sound, and ultrasonic sensors all provide information to the NXT brick. Click picture for a larger image.

You use special electrical cables to connect all the motors and sensors to the NXT.

Besides the electronic parts, which invariably get the most attention, there are hundreds of additional pieces that mainly serve structural and mechanical purposes. Most of these non-electronic pieces belong to the "TECHNIC" category of LEGO parts, which are radically different from the familiar LEGO bricks.

Figure E shows just a sampling of parts from the NXT set; all the non-electronic parts in the kit fall into one of four categories: beams, connectors, gears, and miscellaneous pieces. With the variety and quantity of pieces in the NXT set, it would be difficult to exhaust the building possibilities.

FIGURE E

This is a sampling of parts from the NXT set. Click picture for a larger image.

Programming
I mentioned that the NXT is a "programmable" microcomputer, but programmable in what sense? While you can perform limited programming on the NXT itself, you'll do the majority of programming on your home computer and then download the instructions to the NXT.

The NXT set includes a graphical programming language called "NXT-G" that is easy to use but very powerful -- and compatible with both PC and Mac. Figure F shows the colorful interface and some of the programming "blocks" that make up a program.

FIGURE F

This is a sample NXT-G program. Click picture for a larger image.

The NXT-G tutorials found on the unofficial "NXT Tutorial" Web site (see http://www.ortop.org/NXT_Tutorial/) are an excellent resource if you'd like to learn more about NXT-G.

If you'd prefer a text-based programming language, you're not alone. A number of unofficial text-based languages for the NXT have been released in the past year, and most of them are free and even more powerful than NXT-G.