A micro controller is an integrated circuit that is capable of running programs. There are many instances of those on the market today from a variety of manufacturers. The prices of these micro controllers keeps falling. In the hobbyist market, an open source architecture called "Arduino" that uses the Atmel range of processors has caught the imagination of countless folks. The boards containing these Atmel chips combined with a convention for connections and also a free set of development tools has lowered the entry point for playing with electronics to virtually nill. Unlike a PC, these processors are extremely low end with low amounts of ram and storage capabilities. They won't be replacing the desktop or laptop any time soon. For those who want more "oomph" in their processors, the folks over at Raspberry PI have developed a very cheap (~$45) board that is based on the ARM processors that has much more memory and uses micro SD for persistent data storage. These devices run a variant of the Linux operating system. I'm not going to talk further about the Raspberry PI as it is in the class of "computer" as opposed to microprocessor.
With this textbook you will learn the basics about computers, basic electronics, sensor and measurement technology and programming. We will also learn how to combine software and hardware and how we can communicate with the outside world using computer programs and create simple prototypes
The Arduino is a small, inexpensive computer that can be programmed to control endless creations limited only by your imagination. As you’ll soon see, the Arduino can be used to make a whole host of projects, like a ghost detector, joystick-controlled laser, electronic die, laser trip wire alarm, motion sensor alarm, keypad entry system, and many others. All of these projects are easy to build and have one thing in common—they use the power of the Arduino. In the early 1980s, I picked up a great Penguin paperback titled something like Gadgets and Gizmos, hidden away in a local bookstore. The projects were simple ones like making a working lighthouse using flashlight bulbs and building a revolving display table using an old clock. The ideas in that book sparked my imagination, and I’ve been creating ever since.