NXT Reviewed

LEGO Mindstorms NXT Review

So you have seen the new mindstorms offering from Lego and are trying to decide wether its worth the $399 AUD? ($250 US) Here I will go through what you get in the standard kit and how it fairs as a robotic platform.

Whats in the box

Everything comes in a nice big box with a cardboard flap on the front that shows you all of the pieces that come in the kit:

The main components are:

The Lego NXT Brick

This is a pretty impressive robot controller and is ‘more than meets the eye’ The brick takes 6 AA Batteries and sports 3 connectors for Servo Motors 4x Sensor connectors and a USB port for loading programs. The brick also has Bluetooth which can be used for both programming the brick and for the brick to talk to other bluetooth devices. There is also a screen, speaker and four buttons on the brick which are all programmable.

For the more advanced user wanting to take the NXT a level further the connectors on the NXT are in fact I2C compatible. This means that you can create your own custom electronics and connect them into the NXT.

3x Servo Motors

The servo motors for the NXT are variable speed and have encoders so you can tell how far they have turned. They are also ‘intelligent’ when you write basic programs for  your bots it will make sure that your robot goes in a straight line.

A Sonar Sensor

The sonar sensor is pretty standard. It measures the open air distance to objects from between 6 to 150cm with varying levels of accuracy (This is a limitation of sonar sensors).

A Touch Sensor

Just a simple switch

A Light Sensor

Quite clever, detects level of ‘grayness’ and has a LED to try and improve its accuracy. You can sort-of detect colors by how much light they reflect.

A Sound Sensor

The microphone detects sound levels which can be used to detect clapping and other noises.

Programming your construction

There are a few ways you can program your NXT bot.

With the included Mindstorms Sofware

This is great if you are a beginner or have no programming skills. Makes programming actions nice and easy. The interface is based on LabView and basically you drag action blocks onto a canvas and connect them together.

With Miscrosoft Robotics Studio

This has got to be the visa preffered option if you are a programmer. Basically the MSRS Studio from Microsoft allows you to ‘remote control’ the NXT unit via bluetooth. This means you can write .NET framework code in C# or VB and apply it to your bot. Also if you are familiar with MSRS you will know you can re-use your code on non NXT robots.

I have a simple tutorial on using MSRS with your NXT here .

Should you get it?

Cons

  • You miss out on building the more basic aspects of the robot.
  • High cost outlay (in its defence everything you need is in the kit, if you were to build something like this yourself it would cost at least $1000)
  • Needs more sensors! you really need alot more sensors to do more advanced robotics projects (you can buy sensors seperately).
  • Sensors use a less common variation of a rj11(phone) connector.

Pros

  • Easy to use/program.
  • Great value for money.
  • Can build a working robot in an afternoon (no wasting hours just to get something to work).
  • Fun – the kit is very well designed – there are tons of great vids on YouTube.
  • Lets you test your robot ideas quickly.

My recommedation would be if you are new to robotics and havent fiddled with hardware alot you should definitely get an NXT. You will gain a huge understanding of how hardware and software interacts. Also if you want to start making your own hardware you can and connect it to your NXT. However if you enjoy building electronics and don’t mind spending hours making your own cicruits the NXT is probably not for you.

I tend to put myself in the latter category (I like to get my hands dirty and make ‘everything’) however i still have fun making random stuff with my NXT while i work on my other projects (which tend to take a while).