Pros & Cons
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- Well-built.
- Easy to follow instructions.
- Fun and learning for all ages.
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- Some instructions are all visual.
- Similar-looking parts can lead to confusion.
- Bluetooth lacks detailed instructions.
Since 1998, LEGO's Mindstorms products have generated a veritable legion of young robot builders, and the company's NXT is the most significant update to its unique robot-building kit to date. The kit has, in fact, been incorporated as the grade-school level component of Dean Kamen's For Inspiration and Recognition of Science and Technology (FIRST) science competition, wherein students build robots that compete in mini soccer and other mini forms of arena-based sports.
Opening the packaging for LEGO Mindstorms NXT robotics learning kit can be a bit overwhelming. It's filled with a seemingly endless number of part packets filled with LEGO pieces ranging from 8-inch-long beams to grommets the size of a push-pin head. For anyone who has ever bought any kind of LEGO kit, this is par for the course. The big difference with NXT is the inclusion of a programming brick (roughly the size of two PDAs stacked together), one USB cable and a collection of RJ11-like cables, motors (encased in LEGO plastic), and the all-important sensors (sound, sight, touch, and distance).
This version of the kit raises the ante in a number of ways. The LEGO pieces have been retooled and new sensors have been added. For instance, there's an ultrasonic "eye" and a sound module, plus a sensor for light and color. The programming brick, aka "The NXT Intelligent Brick," has had a big makeover. It's now a spiffy gray and white, with a much larger, though still monochrome, LCD screen. It also has integrated Bluetooth, a 32-bit processor (up from the original brick's 8-bit CPU), more ports, a true sound speaker (so some of your creations can "talk"), and more. LEGO has even opened up the source code for the NXT brick firmware to encourage Mindstorms NXT hacking. Likewise, the software, developed in conjunction with National Instruments, offers a completely new drag-and-drop interface. Of course, before you can program it, you actually have to build your robot.—
Construction Phase
As my son (he's 11, roughly the right age to dive into Mindstorms robot-building activity) and I dug into the packets, I made the, I think, critical decision to take each packet's contents and empty it into a resealable Ziploc bag. Why LEGO pieces don't come this way is a mystery to me.
We started with the instructions to build a basic two-wheeled bot that would let us test the programming brick and sensors in a fairly rudimentary way. The LEGO building instructions include virtually no words. Instead, they're all pictures of parts and detailed visual guidance on how to put them together. Match up all the parts you need with their images on the paper and then simply follow the building instructions. This works like a charm, for the most part, but every once in a while it's unclear from the image if you should use a gray or black piece or if it's a long or short black connector. As a result, my son and I spent more time than I'd like redoing parts for which we had inadvertently used the wrong piece. Ultimately, I learned to rely heavily on my son, who has built countless LEGO models and is comfortable with LEGO's sometimes arcane system of hieroglyphics.
The Mindstorms NXT programming "brick," thankfully, remains a model of simplicity. This version includes numbers on the motor ports and "A," "B," "C," and "D" labels for the sensor ports. As long as you always connect the right motors and modules to their assigned ports, programming is a virtual no-brainer.
Likewise, aside from building your first model, it requires little effort to begin programming. The quick-start guide takes you through accessing the NXT's monochrome LCD screen menus to open files and program simple motor actions and sensor attributes. You can even daisy-chain these programming actions (as you would in the NXT PC-based software) right on the 2-inch screen. My son and I followed the guide and placed each sensor, one at a time, on the newly built two-wheeled robot. Once the robot was completed, we were able to make it turn, race forward and back, and stop when we clapped our hands.—
Program It
To take our programming and robot-building to the next level, we needed to install the NXT software. Requiring an 800-MHz PC, 256MB of RAM and as much as 300MB of hard drive space, the software could tax older PCs (the kind you often hand down to your kids). Even so, the application is, like the rest of the NXT system, a snap to set up.
Within the software, a panel on the right side, called the Robo Center, guides you through building the "Tribot" model in virtually the same manner as the printed instructions. No words or audio guidance, just step-by-step pictures. We had no trouble building the ball-carrying bot, which uses all of the kit's three motors and four sensors. The area also has instructions for four robot categories: Vehicles, Machines, Animals, and Humanoids. Each comes with one set of robot instructions, corresponding to the aforementioned Tribot vehicle, the RoboArm T-56 machine, Spike animal robot, and the humanoid Alpha Rex.
When you're done constructing the Tribot, you expand the collapsed programming region for step-by-step visual guidance on how to program it to execute several entertaining and educational feats. Visual help on the right shows you exactly what to do in the workspace on the left. That area is where you place and connect programming "blocks" or modules (they connect with virtual LEGO pieces). You program each module in the software's configuration panel right below the workspace, which changes dynamically depending on the module you choose.
Each programming block offers an extraordinary and almost daunting amount of flexibility. Yet once you get over the hurdle of understanding all the options and how they affect the way your robot reacts and responds, it becomes quite intuitive. A move block controls your motors (motors are connected to ports A, B, C, or any combination of the three), direction (forward, reverse, stop), power (zero to 100 to control the speed of rotation), duration (unlimited or in increments of degrees, rotations, or seconds), and next action. So if you set the rotation to end at 6 seconds, the motors know to stop or coast forward (useful, say, if the robot is on a hill).
Blocks are connected in a linear pattern, but you can also create subroutines that you hook up to the main program. Once the entire program is built, you'll be able to use the software-based five-button controller to download some or all of it to the NXT, which connects to your PC via the included USB cable.
We followed the software guidance to make our robot race forward on the kit's included Test Pad (a large fold-out sheet that includes a black line, colored squares, and measurements that can all be used by you and your robot's sensors), find a ball with its touch sensor, pick it up when we clapped our hands, and then turn around and roll until it found the map's dark black line. At this point, our little automaton dropped its spherical cargo.
The software also includes a My Portal area, through which you can access the robust Mindstorms community and forums, additional building and programming instructions, and software downloads. The Mindstorms community is vast, but sometimes it seems a bit stale. The Hall of Fame has robot creations only up to 2001.—
Feeling Blue About Bluetooth
The only time I ran into real trouble was when I tried to use the NXT's native Bluetooth capabilities. LEGO claims that you can control your robots via a Bluetooth-enabled PC or mobile device. I used the NXT onboard menus to make sure the Bluetooth beacon was on and then used an
There's really no help provided in the documentation, in print or online, for how to set up and use these Bluetooth capabilities. Still, I forged ahead. The NXT at first found a Bluetooth-enabled keyboard in an adjacent office, but it eventually latched onto the cell phone. Likewise, the cell phone saw the NXT. Unfortunately, the phone wanted a passkey, and I didn't have one. The NXT could not connect with the phone either. LEGO said it was looking into the issue.
This minor disappointment aside, I really can't think of a bad thing to say about LEGO's Mindstorms NXT. It's far easier to use and understand than
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