Make: JavaScript Robotics: Building NodeBots with Johnny-Five, Raspberry Pi, Arduino, and BeagleBone

487 Pages·2015·23.27 MB·English

by  Backstop Media

Make: JavaScript Robotics
Rick Waldron, Anna Gerber, David
Resseguie, Emily Rose, Susan Hinton,
Sara Gorecki, Bryan Hughes,
Andrew Fisher, Julian David Duque,
Pawel Szymczykowski, Donovan
Buck, Jonathan Beri, Kassandra
Perch, Raquel Vélez, Lyza Danger
Gardner
Make: JavaScript Robotics
by Backstop Media and Rick Waldron Copyright © 2015 Backstop Media, LLC.
All rights reserved.
Printed in Canada.
Published by Maker Media, Inc., 1160 Battery Street East, Suite 125, San
Francisco, California 94111.
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Editor: Brian Jepson
Production Editor: Melanie Yarbrough
Copyeditor: Tracy Brown Hamilton
Proofreader: Jasmine Kwityn
Indexer: Meghan Jones, WordCo Indexing
Interior Designer: David Futato
Cover Designer: Brian Jepson
Cover Photographer: Pawel Szymczykowski
Illustrator: Rebecca Demarest
April 2015: First Edition
Revision History for the First Edition
2015-04-03: First Release
See http://oreilly.com/catalog/errata.csp?isbn=9781457186950 for release
details.
The Make logo and Maker Media logo are registered trademarks of Maker
Media, Inc. Make: JavaScript Robotics and related trade dress are trademarks of
Maker Media, Inc.
Many of the designations used by manufacturers and sellers to distinguish their
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have been printed in caps or initial caps.
While every precaution has been taken in preparation of this book, the publisher
and author assume no responsibility for errors or omissions, or for damages
resulting from the use of the information contained herein.
978-1-45718695-0
[TI]
Preface
By Rick Waldron
I love programming and I also love making things. When I discovered Chris
Williams’ node-serialport module (for Node.js), I remember thinking, “Now I
can program the things that I make.” So I did! I contributed an Arduino sketch
that printed a photoresistor sensor value to the open serial port and a small
JavaScript handler program that listened for data and printed a “graph” to the
terminal. Months later, I started contributing to Cam Pedersen’s duino project,
until Julian Gaultier approached me with his JavaScript implementation of the
Firmata protocol. From there, we set out to build a collection of high-level
component classes with one goal: to make it easy and fun to control hardware
with JavaScript. This book will show you what we built and how to use it to
program the things that you make.
While the physical challenges of engineering a hardware project remain the
same as they would for a project programmed in any other language, this book is
going to show you how to think about that hardware in terms of objects that
maintain state and provide control behaviors in the form of intuitively designed
interfaces.
So, how would you verbally describe adding an LED to a project and then
turning it on? You might say, “Connect the LED to ground and pin 9, then turn it
on.” Using the Johnny-Five framework, that would be written as:
// Connect the LED to ground and pin 9
var led = new five.Led(9);
// then turn it on
led.on();
What about connecting a servo and then setting its horn to a specific angle in
degrees? “Attach the servo to pin 10 and position its horn to 110°.” Here’s what
that looks like:
// Attach the servo to pin 10
var servo = new five.Servo(10);
// position its horn to 110°
servo.to(110);
These examples both illustrate an output, but what about input? Consider how
Arduino sketches work: they generally rely on a program loop and often
introduce some form of delay when reading and processing input. This means
that your Arduino sketch is blocked whenever it is waiting for input. When
writing programs in JavaScript, the process is never blocked; instead, your
handlers wait for data to arrive and process it asynchronously:
var sensor = new five.Sensor("A0");
sensor.on("data", function() {
console.log(this.value);
});
These are trivial examples, but they illustrate the patterns that you will see
repeated consistently throughout this book. Each project will show you how to
construct it in the physical sense, then construct it in the abstract programming
sense, and the latter will align with the former.
With these concepts, you will build and program:
Walkers, typers, swimmers, and rovers (Chapters 1, 2, 3, and 4)
A dancing hexapod (Chapter 5)
Voice-activated relay control (Chapter 6)
An indoor sundial (Chapter 7)
Holiday, mood, or anytime lighting (Chapters 8 through 10)
A security and notification system (Chapter 11)
Sonar-based artificial intelligence (Chapter 12)
A delta bot (Chapter 13)
Musical shoes (Chapter 14)
For me, the most exciting part about this book is the authors themselves. This
group is an excellent representation of NodeBots community members that have
stood out since the very beginning. They are more than just writers or engineers:
they are teachers, communicators, leaders, and (in my opinion) heroes. It would
be an understatement to say that I couldn’t have done it without them.
Enough talk, more rock. These projects do not have to be done in any specific
order, so take a look at the Table of Contents, find a project that sounds like fun,
order, so take a look at the Table of Contents, find a project that sounds like fun,
and start building!
Conventions Used in This Book
The following typographical conventions are used in this book:
Italic
Indicates new terms, URLs, email addresses, filenames, and file extensions.
Constant width
Used for program listings, as well as within paragraphs to refer to program
elements such as variable or function names, databases, data types,
environment variables, statements, and keywords.
Constant width bold
Shows commands or other text that should be typed literally by the user.
Constant width italic
Shows text that should be replaced with user-supplied values or by values
determined by context.
This element signifies a tip, suggestion, or general note.
This element indicates a warning or caution.
The part numbers in each chapter use the following abbreviations:
MS: Maker Shed
AZ: Amazon
AF: Adafruit
SF: SparkFun
Using Code Examples
This book is here to help you get your job done. In general, you may use the
This book is here to help you get your job done. In general, you may use the
code in this book in your programs and documentation. You do not need to
contact us for permission unless you’re reproducing a significant portion of the
code. For example, writing a program that uses several chunks of code from this
book does not require permission. Selling or distributing a CD-ROM of
examples from Make: books does require permission. Answering a question by
citing this book and quoting example code does not require permission.
Incorporating a significant amount of example code from this book into your
product’s documentation does require permission.
We appreciate, but do not require, attribution. An attribution usually includes the
title, author, publisher, and ISBN. For example: “Make: JavaScript Robotics by
Jonathan Beri, Donovan Buck, Julian David Duque, Andrew Fisher, Lyza
Danger Gardner, Anna Gerber, Sara Gorecki, Susan Hinton, Bryan Hughes,
Kassandra Perch, David Resseguie, Emily Rose, Pawl Szymczykowski, Raquel
Velez, Rick Waldron (Maker Media). Copyright 2015 Backstop Media, 978-1-
4571-86950.”
If you feel your use of code examples falls outside fair use or the permission
given here, feel free to contact us at [email protected].
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Maker Media, Inc.
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Make: unites, inspires, informs, and entertains a growing community of
resourceful people who undertake amazing projects in their backyards,
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All source code for the examples in this book can be found at:
https://github.com/rwaldron/javascript-robotics.
We have a web page for this book, where we list errata, examples, and any
additional information. You can access this page at: http://bit.ly/1KUV1p2.
If you feel your use of code examples falls outside fair use or the permission
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Acknowledgments
Julián Duque
NodeBots is all about learning while having fun and especially for me it’s a way
to achieve social impact. Everything started at NodeConf 2013 — it was my first
time using Johnny-Five on a NodeBots workshop guided by Rick Waldron and
Raquel Velez. My first attempt was with a piezo buzzer, but at that time the
library didn’t support the Piezo class, so I asked Rick how to use it and he said
to me, “I wasn’t able to make it work, how about a pull request?” That’s how I
started contributing to the project. On the other hand, Raquel gave me my first
Arduino kit as a gift and told me, “Take this with you and teach what you’ve
learned in Colombia.” That humble action was so inspiring for me and I started a
NodeBots chapter in Medellín, Colombia. I also helped create the communities
in Uruguay, Guatemala, and Mexico through workshops and talks. Rick and
Raquel, thank you so much for inspiring me and letting me be part of this Maker
revolution.