While this book is not a book on electronic theory, there are a few core principles that are important to have an appreciation for because they impact circuit design and how they interface with your Raspberry Pi. The goal of this section is to present you with a basic understanding of why circuits are designed in certain ways and how this relates to GPIO interfacing. Armed with this basic knowledge, I hope it provides you with the incentive to explore the core ideas and principles in more depth. You'll find suggested resources in the Further reading section, at the end of this chapter.
We will start our coverage of electronic principles with what is arguably two of the most fundamental electrical principles of them all – Ohm's Law and power.