Beginning Arduino, Second Edition

CHAPTER 6

Binary Counters and Shift Register I/O

We are now going to go back to controlling LEDs. This time, however, we will not be driving them directly from the Arduino. Instead we are going to use a fantastic little chip known as a shift register. These ICs (integrated circuits) will enable us to control eight separate LEDs using just three pins from the Arduino and, as you will see in Project 18, a total of 16 LEDs, again using just three pins from the Arduino.

To demonstrate the way the data is output from these chips, we are going to create two binary counters, first using a single shift register and then moving onto two chips cascaded ...