Designing Embedded Hardware, 2nd Edition

Chapter 4. Electronics 101

...in reality, nothing but atoms and void

—Democritus

In writing this book, my hope is to bring to you an understanding of the design process involved in producing an embedded computer system. To this end, I have kept the electronics, the chips, and the systems I have used as simple as possible. I want you to understand the big picture without getting lost in detail. But, however simple I keep the computer designs, you won't get very far without at least a very rudimentary understanding of electronics. So what I want to do in this chapter is give some basic background theory to guide you on your way. Electronics is a truly vast and complicated multidisciplinary field, and it is not possible to cover even a thousandth of it here. I won't even attempt to. What I will do is give you an understanding of the basic principles necessary for embedded computer engineering in a simplified, and hopefully easy to understand, way. The rest of the vast mountain, I will leave unvisited. If you want to learn more, pick up a copy of Paul Horowitz and Winfield Hill's The Art of Electronics (Cambridge University Press). It's a great introductory text.

Voltage and Current

It's all about electrons. It is from their very name that we derive the term electronics. Electrons are subatomic particles with a negative charge. They are bound to positively charged atomic nuclei through Coulombic attraction. The classical physics view was to think of electrons "orbiting" the nucleus, ...