Python All-in-One For Dummies, 2nd Edition

Chapter 1

Introducing Physical Computing

IN THIS CHAPTER

Understanding how to use small computers

Using a Raspberry Pi to sense the environment around you

Making your computer do physical things

We think it's more difficult to learn about the software (Python) than the hardware, which is why in the last several hundred pages we've focused on learning how to program in Python. But now it's time for you to learn how to make your computer do something with Python. Making your computer do mechanical things — and interact with the world around you — is called physical computing!

In this chapter, we hook up various sensors and motors to a Raspberry Pi computer. Although the voltages we use — 3.3V and 5V — are not particularly dangerous to people, hooking up things incorrectly can burn out the computer or sensors. For this reason, follow these two rules assiduously:

• Rule 1: Turn off all power before you hook up or change any wires.
• Rule 2: Double-check your connections, especially the power connections, which are power and ground. To find out why these are the most important wires to ...