This is a book about making electronics projects that actually do things. Unlike the thousands of electronics hobby books before it, this book strives not to create for the sake of creating, but rather to create for the sake of utility and function. So while other books are content to teach the basics of electronic design, the output of which is often a series of cleverly blinking lights, sensor inputs, or basic switches, this book assumes that switches, lights, and sensors are only as good as the function they perform.

Often, electronics hobby books begin with the basics of resistors and simple circuits, and end with circuits that take input switches to make LEDs blink in different patterns. Appropriately, this book picks up where those left off, and does not pretend to offer nearly as exhaustive coverage of the basics as the many books before it. Instead, our opening project chapters cover switched inputs, LED outputs, and what other books would call “complex” circuits. This is done to make a statement, not to discourage beginners. Indeed, while the basics of electrical engineering can be helpful, we believe firmly that they are not necessary in this age to create functional electronics. Just as an understanding of digital electronics is not necessary to know how to plug an external USB hard drive into one’s laptop, we aim to demonstrate that creating electronics devices with modular components is equally accessible.

This book answers the challenge of the modern digital hobbyist. The modern hobbyist has a new set of expectations that have left many other circuit books wanting. No longer is the nighttime and weekend tinkerer content with “Knight Rider” circuits and “simon” games – though these serve countless hours of enjoyment. The modern hobbyist must make better MP3 players, portable gaming systems, RFID and WiFi signal scanners, laser-controlled light shows, and 3-dimensional printing machines. In many ways, the threshold for invention has never been higher, and so this book is meant to provide new tools to a new age of more efficient, and more productive hobbyist.

If the age of hyperlinks and Wikipedia has taught us anything, it’s that most books can have many, constantly changed, dynamic structures, or “ontologies” as the academic theorists like to call them. This book suffers the constraints of static print in the same way, and so we debated over the ideal way to organize the chapters. On the one hand, we felt inclined to organize the book starting with the easiest chapters first, building up to the more complex chapters. After all, this is how most electronics and nonfiction technical tutorial books are written. But this book had to be different. We chose instead to organize our chapters by the underlying modules one would need in order to build working devices. Thus, beginning chapters require only a single, basic module, middle chapters explore projects with 2 modules, and final chapters explore potential projects with 3 or more components. Our organizing theory is that beginners in the field of modular electronics will begin by purchasing basic cheaper building blocks, and gradually expand their collections with more complex modules.

In the same sense as the tired “tip of the iceberg” metaphor, this book also represents much more to come. One could say that this is a book about the intersection of open source hardware, physical computing, and modular electronics. It therefore represents a combinatorial explosion of potential electronic products and devices created with simple parts, whose complexity arises from their utility, which we suspect is greater-than-sum-of-the-parts (there goes another tired metaphor). Historically speaking, the hobbyist’s tools have closely mirrored those of the storied American inventors, and it is the authors’ belief that these two roles play an indistinguishable role in the economy at large. But we’ll try not to be too pedantic and metaphysical, after all, the reason we’re all here is a shared passion and interest in cool, down-to-earth projects that actually do real things. That’s why we’ve written this book, and that’s what we’re hoping to inspire in others through this book.

This book is the start of a multi-volume series. The next volume deals primarily with the business implications of the contents of this volume, and speaks directly to the new types of businesses one can start with the projects listed in this volume. We hope therefore to inspire the technical curiosities with this volume, and the aspiring entrepreneurial minds with the other volume. Truthfully, we find it hard to speak of one without the other, as the interplay between both engineering and business has arguably never been so tightly linked as it is today.

Above all, we hope you enjoy the projects in this book. If we have inspired you to create your own projects and share them back with us, we have succeeded. Please write, email, blog, text message, video post, or better yet, come back to us with a new communication medium that you happen to invent with projects in this book.

-Matt