C H A P T E R  6

Binary Counters

You are now going to go back to controlling LEDs. This time, however, you won't be driving them directly from the Arduino. Instead, you're going to use a fantastic little chip known as a shift register. These ICs (Integrated Circuits) will let you control eight separate LEDs using just three pins from the Arduino. But wait, there's more: in Project 18, you'll control a total of 16 LEDs, again using just three pins from the Arduino.

To demonstrate the way the data is output from these chips, you are going to create two binary counters, first using a single shift register and then moving onto two chips cascaded (you will learn what cascading is in the aforementioned Project 18). Chapter 6 is going to delve into some pretty advanced stuff so you might want to pour yourself a stiff drink before going any further.