Exploring Arduino: Tools and Techniques for Engineering Wizardry

CHAPTER 7

Shift Registers

Parts You'll Need for This Chapter

Arduino Uno

USB cable (A to B for Uno)

Red LEDs (×8)

Yellow LEDs (×3)

Green LEDs (×5)

220Ω resistors (×8)

SN74HC595N shift register DIP IC

Sharp GP2Y0A41SK0F IR distance sensor with cable

Jumper wires

Breadboard

CODE AND DIGITAL CONTENT FOR THIS CHAPTER

Code downloads, videos, and other digital content for this chapter can be found at www.exploringarduino.com/content/ch7.

In addition, all code can be found at www.wiley.com/go/exploringarduino on the Download Code tab. The code is in the chapter 07 download and individually named according to the names throughout the chapter.

As you chug away building exciting new projects with your Arduino, you might already be thinking: “What happens when I run out of pins?” Indeed, one of the most common projects with the Arduino is using the platform to put an enormous number of blinking LEDs on just about anything. Light up your room! Light up your computer! Light up your dog! Okay, maybe not that last one.

But there's a problem. What happens when you want to start blinking 50 LEDs (or controlling other digital outputs) but you've used up all of your I/O pins? That's where shift registers can come in handy. With shift registers, you can expand the I/O capabilities of your Arduino without having to pay a whole lot more for a more expensive microcontroller with additional I/O pins. In this chapter, you'll learn how shift registers work, and you'll implement both the software and hardware ...