Introduction

Welcome to LEGO Mindstorms NXT: The Mayan Adventure. I don't like to make assumptions, but since you're holding this book, I'm guessing that you are either an owner of the new Lego Mindstorms NXT robotics kit or are interested in the robotics kit and what can be done with it. (Or maybe you just thought the cover looked interesting and were wondering what robots have to do with the ancient Mayan civilization.)

This book is fairly unique, and I'll tell you why. For the earlier version of Mindstorms (called Mindstorms Robotics Invention System, or RIS for short), numerous books were written, most of which focus on building rather extravagant robots, hacking the Mindstorms processor (called the Brick), and doing other wild things with the product. And the books are great! Many of them show you, step by step, how to build and program very unique creations. But after reading them, I felt that a few things were missing.

The first thing I noticed was a minimal amount of "where to start" type information. The first time you open up a Mindstorms robotics kit, you might feel a little overwhelmed at the sheer number of pieces (almost all of them small) in the box. You get an instruction manual and some sample robots to build, but there is very little information for those new designers who are asking "How do I start designing a robot?"

The second item I found lacking was incentive. There are lots of robots that can be built, but many Mindstorms owners get stuck trying to come up with a problem to solve. "What should I build?" is a frequently asked question. There are robotics competitions, with fixed tasks to complete and well-defined conditions for winning, but what if you're not into competitions or lack access to them? Where can a person find challenges to take on and accomplish?

The last gap involves training. Many of the books on the market for the RIS are great at telling you how to build and program your robots, but many times the explanations aren't really explanations—they're instructions: "Put this piece here" and "Drop that there." What is missing are the reasons for doing something (or, at least, the authors' reasons).

With The Mayan Adventure, I've tried to fill in these gaps as follows:

• To answer the question "How do I start designing a robot?" I've provided something called a Design Journal page. This is a worksheet that I use (and encourage you to use) to demonstrate the development of the book's robots, using a step-by-step method. It's not the only method out there, but it's my hope that you will find it useful as a way to keep your thoughts organized and to help you move forward in a constructive way.
• As for lack of incentive, I've divided the book into five sections, each of which involves a challenge. Each section has part of a fictional storyline that sets up a reason for building a robot. The story is fictional, but the challenges give you plenty of encouragement to experiment and develop your own robots.
• And when it comes to training, I provide solutions to the five challenges by walking you through the development of my robots, their construction, and their programming. I give you some "Do this" and "Do that," but always with an explanation.

I don't use a lot of fancy, technical terms. There are some in there (it's unavoidable when dealing with programming), but I think you'll find that the book is written in an easy-to-follow way and, hopefully, you'll also find the process fun.

If you're completely unfamiliar with NXT, you really should install the NXT-G software (the CD that comes with the kit) and go through the included tutorials. These tutorials will teach you the basics of how to use the software as well as give you some basic construction skills. To get the most out of this book, you do need to at least be comfortable with using the NXT components, opening the NXT-G software, creating and saving programs, and uploading programs to your robot. If you're comfortable with this short list, then you're almost ready to start ...

How This Book Is Organized

As I mentioned earlier, I've divided the book into five sections. Each section is further divided into four chapters. The fictional storyline starts in Chapter 1, continues in Chapters 5, 9, 13, and 17, and concludes in Chapter 21. The storyline is where you find the details of a particular challenge (for that section); these details are important because they help you to determine the robot's objectives.

Chapters 2, 6, 10, 14, and 18 are what I call the "theory" chapters. Don't let that word scare you, though. When I say theory chapters, I simply mean that these chapters give you plenty to think about—what does the robot need to do, what can it not do, what parts should be used, and what parts should not be used. I use the Design Journal page in these theory chapters, and I've provided five blank copies in the back of the book for you to follow along with me (or use them to develop your own robots).

Chapters 3, 7, 11, 15, and 19 are the building instructions for the robots. In each chapter, you'll find a set of photos that walks you through building my version of the robot. You can follow my steps and build the exact same robots I include in the book, or you can come up with your own creations. (If you find you're missing a part or something just doesn't snap together properly, the best part about Lego robots is that there's always a workaround—another way to connect something or a combination of parts that can be used as a substitute. Don't stress about it—use your creativity and find an alternative solution!)

Chapters 4, 8, 12, 16, and 20 provide the programming instructions. I use plenty of screenshots to show you how to configure each block that is used in the NXT-G programming language. If you have used my building instructions, you can also use the programming instructions. These chapters also include instructions for you on how to set up a test environment for testing your robots and see if they can complete the challenges.

Finally, I've included some appendices for you; references, instructions for documenting your own robots, and other stuff. Check them out.

Who Is This Book For?

It doesn't matter if you are 10 years old or 50, building robots is fun. This book is for everyone who wants to build some new Mindstorms NXT robots and have fun. I don't expect you to be a programming guru—I'm certainly not. I also don't expect you to have advanced degrees in robotics, engineering, or computer science. Let's all remember that Lego Mindstorms NXT is, ultimately, a Lego product. It's a TOY! It's supposed to be fun, not stressful.

If you're a kid, this book can be a great way to get your mom or dad interested in your hobby. And if you're a parent, this book can be a great way to have some fun with your kids. I think you'll see that it's fun to create challenges for yourself (or someone else) and then try to build some great robots to overcome those challenges.

What You Need to Use This Book

The only things you need besides this book are a Lego Mindstorms NXT robotics kit and a computer to run the software and upload programs to your robots. There are currently two versions of the Mindstorms NXT kit—the retail version that you can buy online or in stores, and the education version that Lego sells to teachers, schools, and individuals. There are differences in the types of parts that come in the two kit versions, so please be aware that all the robots in this book have been built with the retail version. If you own the education version, that's okay. It just means that if you find I'm using a part that you don't have, you'll have to improvise. Don't let that bother you—just look at it as another challenge to overcome and something new to learn.

Extras for This Book

Extra Design Journal pages can be downloaded from the Source Code page on the Apress Web site, at http://www.apress.com.