In Chapter 3, you explored the deep-down-inside parts at the heart of the Arduino, the Atmel AVR. With so much internal complexity, it’s hard to believe that you would need anything else; but you do.
First, the chip needs power to perform all that magic. Second, if you don’t connect the chip to something, no one will ever be able to tell that anything is happening.
Let’s take a detailed look at each of the major areas in the basic Arduino circuit. These areas include the following:
The chapter also looks at the mechanical form factor in some detail and includes a special section on the Universal Serial Bus (USB) interface ...