Laurens Valk - The LEGO MINDSTORMS NXT 2.0 Discovery Book

quick building reference chart

THE LEGOMINDSTORMS
NXT 2.0DISCOVERY BOOK

a beginners guide to building and
programming robots

laurens valk

THE LEGO MINDSTORMS NXT 2.0 DISCOVERY BOOK. Copyright 2010 by Laurens Valk.

All rights reserved. No part of this work may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage or retrieval system, without the prior written permission of the copyright owner and the publisher.

Fifth printing

14 13 12 5 6 7 8 9

ISBN-10: 1-59327-211-1
ISBN-13: 978-1-59327-211-1

Publisher: William Pollock
Production Editor: Riley Hoffman
Cover and Interior Design: Octopod Studios
Cover Photograph: Jochem de Klerk
Technical Reviewers: Damien Kee, Martijn Boogaarts, and Richard Li
Copyeditor: Kim Wimpsett
Compositor: Riley Hoffman
Proofreaders: Nancy Sixsmith and Xander Soldaat
Indexer: Valerie Haynes Perry

For information on book distributors or translations, please contact No Starch Press, Inc. directly:
No Starch Press, Inc.
38 Ringold Street, San Francisco, CA 94103
phone: 415.863.9900; fax: 415.863.9950;

Library of Congress Cataloging-in-Publication Data
Valk, Laurens.
The LEGO Mindstorms NXT 2.0 discovery book : a beginners guide to building and programming robots / Laurens Valk.
p. cm.
Includes index.
ISBN-13: 978-1-59327-211-1
ISBN-10: 1-59327-211-1
1. Robots--Design and construction--Popular works. 2. Robots--Programming--Popular works. 3. LEGO toys. I. Title.
TJ211.15.V353 2010
629.892--dc22
2010011157

No Starch Press and the No Starch Press logo are registered trademarks of No Starch Press, Inc. Other product and company names mentioned herein may be the trademarks of their respective owners. Rather than use a trademark symbol with every occurrence of a trademarked name, we are using the names only in an editorial fashion and to the benefit of the trademark owner, with no intention of infringement of the trademark.

LEGO, MINDSTORMS, the brick configuration, and the minifigure are trademarks of the LEGO Group, which does not sponsor, authorize, or endorse this book.

The information in this book is distributed on an As Is basis, without warranty. While every precaution has been taken in the preparation of this work, neither the author nor No Starch Press, Inc. shall have any liability to any person or entity with respect to any loss or damage caused or alleged to be caused directly or indirectly by the information contained in it.

Laurens Valk is a member of the MINDSTORMS Community Partners (MCP), a group of MINDSTORMS enthusiasts who help test and develop new NXT products. He has been inventing robots with the MINDSTORMS NXT sets since their introduction. Laurens enjoys designing robots that can be built with just one NXT set, making it easy for MINDSTORMS fans worldwide to follow his building instructions. One of his robot designs, Manty, appears on the back of the NXT 2.0 sets box as a bonus robot. He is a coauthor of LEGO MINDSTORMS NXT One-Kit Wonders (No Starch Press) and a contributor to The Unofficial LEGO MINDSTORMS NXT 2.0 Inventors Guide (No Starch Press). Hes also a contributor to the popular NXT STEP blog (http://thenxtstep.blogspot.com/). Laurens lives in the Netherlands, where he studies Mechanical Engineering at Delft University of Technology, and he maintains his website about robotics at http://www.laurensvalk.com/.

Dr. Damien Kee holds a PhD in robotics and a bachelors degree in electrical engineering, both from the University of Queensland, Australia. He has built a wide variety of robots, from maze-solving mice to humanoids to robots that dispense traffic cones. Damien has been heavily involved with the RoboCup Junior competition since 2001, and in 2009 he was elected chairman of RoboCup Junior Australia and technical chair of the RoboCup Junior International Rescue Committee. Since 2003, Damien has been conducting robotics workshops for teachers, educators, and students worldwide, and he has written several teacher resource books. He is a member of the MINDSTORMS Community Partners; a contributor to the NXT STEP blog; and editor in chief of The NXT Classroom (http://theNXTclassroom.com/), a website providing resources and support for teachers.

1
collecting the equipment for your robot

2
building your first robot

3
creating and modifying programs

4
working with programming blocks: move, sound, and display

5
waiting, repeating, and other programming techniques

6
understanding sensors

7
using the touch, color, and rotation sensors

8
shot-roller: a robotic defense system

9
strider: the six-legged walking creature

10
using data hubs and data wires

11
using data blocks and using data wires with loops and switches

12
using variables, constants, and playing games on the NXT

13
snatcher: the autonomous robotic arm

14
hybrid brick sorter: sort bricks by color and size

15
CCC: the compact chimney climber

appendix
troubleshooting and solving connection problems

The book you hold in your hands is the result of more than a year of hard work, and I would never have completed writing it without the help of many others. First, Id like to thank Fay Rhodes and Jim Kelly for introducing me to book writing. If I hadnt had the opportunity to coauthor LEGO MINDSTORMS NXT One-Kit Wonders with them in 2008, I might never have considered writing my own book, especially in a language that is not my native tongue.

Next, Id like to thank the LDraw community for developing many tools required to make clear building instructions, especially Philippe Hurbain for making detailed 3D drawings of the NXT set components; Travis Cobbs for developing LDView to visualize the building steps; and Kevin Clague for developing LPUB4, which allowed me to organize my building instructions in a way that would make them easy to follow. Thanks too to John Hansen for letting me use his tool to take screenshots of the NXT display.

Thanks also to all who have been directly involved in this book: Richard Li and Martijn Boogaarts for carefully testing my robots and their building instructions; Jochem de Klerk for taking the cover photograph; Micah Edelblut for taking the photographs used in ; my parents for their advice on how to manage working on this book; and Xander Soldaat for proofreading the book for technical accuracy. Special thanks go to technical editor Damien Kee for reading all of the chapters early on to make sure they were understandable and clear.