Lego Mindstorms NXT review

If you think Lego means kids’ stuff, think again. Mindstorms NXT is a sophisticated robot-building system with both engineering and programming elements. And, although it’s sold in toy shops and marketed as an educational tool, it’s designed to appeal to enthusiasts of all levels, right up to advanced programmers.

Inside the box, you’ll find well over a hundred assorted beams, rods, wheels, sensors and connectors. The use of beams rather than blocks makes Mindstorms feel more like Meccano than Lego, but unlike Meccano it all snaps together without tools. The large number of similar but slightly different components means assembling your robot can involve a lot of tiresome rummaging around.

Also included are three servo motors, which you can use to make your robot move, and four sensors so it can determine information about its surroundings. There’s a touch sensor, which registers when it’s touching other objects; a light sensor, which measures levels of visible light; a sound sensor, which responds to noise; and an ultrasonic sensor that uses simple echolocation to determine how far away it is from a solid object. Finally, the brain of the robot is the NXT Intelligent Brick, a miniature computer that controls the motors and processes input from sensors.

The pack comes with detailed instructions for building several types of robot. You start with a simple tricycle that wheels around in a loop and build up to the flagship model, Alpha Rex, a multifunctional bipedal robot. It’s a good way to learn what you can do, but the fun of Lego has always been in ditching the blueprints and creating your own designs, and here you might find your imagination frustrated by a lack of parts. The kit contains just four proper wheels for moving around and four talons for gripping – a pretty mean allocation for a package costing more than £150. You can extend the set with parts from the Lego Technics range, which uses the same system of beams and connectors, but there’s nowhere to connect extra motors beyond the three provided units.

Once your robot’s assembled, it will need a program to tell it what to do. Programming is carried out offline, in a dedicated environment that runs on a PC or Mac, with finished code compiled and uploaded to the brick via USB. Programs are constructed graphically by dragging command blocks onto an execution path, with each block’s parameters set via a panel at the bottom of the screen. This approach may seem simplistic, but there’s plenty of depth on offer. You can test input from any sensor and divert program flow based on the result. You can create and manipulate Boolean, integer or string variables. And you can implement various types of loop as well. Best of all, you can save any series of blocks as a new block, making it easy to build up complex behaviours.

It’s this versatility that’s Mindstorms’ trump card. As the official website proudly details, enterprising coders have created machines that can write on eggs, feed pets, deal cards and even play noughts and crosses. And, thanks to the brick’s built-in Bluetooth support, your programs can respond to commands from a phone or PDA. If you want to take things further, there’s a full SDK for free download and Brick’s firmware is open source. There’s scope for expansion on the engineering side, too, in the form of extra sensors. These include a compass, an accelerometer, a real-time clock and even a temperature sensor.

In all, although the engineering part of Mindstorms is a slight disappointment, its programmability won us over. It isn’t the world’s most sophisticated development environment, but it’s clear and easy enough to understand that savvy kids will soon get the hang of it – a great selling point, especially since many children now go through school without acquiring any programming skills at all. At £153, it isn’t exactly a cheap Christmas present but, for introducing a child to robotics or indulging your own hobby, there’s nothing quite like it.