Page 468 - Robot Builder's Bonanza

Chapter 35

Understanding

Microcontrollers

icrocontrollers have become the favorite method for endowing a robot with smarts.
MAnd there’s good reason: microcontrollers are inexpensive, have simple power
requirements— usually just 5 volts— and most can be programmed using software on your PC.
Once programmed, the microcontroller is disconnected from the PC and operates on its own.
A microcontroller is a computer- on- a- chip. It contains everything (or almost everything,
depending on the exact model) that’s needed to be a fully functional computer. It contains a
central processing unit that does the thinking, memory for storing programs and data, and
multiple connections that allow it to interface with external devices. In all, the perfect brain for
robots.
In this chapter you’ll learn about microcontrollers in general— what’s inside, how they dif-
fer, and why you might want to choose one kind over another. Then in Part 7 you can learn
specific details about three very popular microcontrollers used in robot projects: the Arduino,
PICAXE, and BASIC Stamp. These chapters include sample projects and programming code
you can try for yourself. Find more in Part 8 and on the RBB Online Support site (see Appen-
dix A for details).

All about Microcontroller Categories

Microcontrollers, or MCUs for short, come in all sizes, styles, and categories. Some are for
esoteric applications, like running a car’s engine or controlling the operation of industrial
furnaces. Others are general- purpose, designed for a wide variety of applications. The latter
kind are the ones we’re most interested in. Figure 35- 1 shows a low- cost modular microcon-
troller designed for experimentation— it contains the MCU itself, plus a liquid- crystal display
and other components for learning about programming microcontrollers.
Here are other ways microcontrollers differ and the benefits of each type.

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