Make: More Electronics

Chapter 15. Experiment 15: It’s All So Logical!

In Make: Electronics I provided an introduction to digital logic, but I avoided the more challenging aspects, and I didn’t deal with components such as multiplexers or shift registers. Logic chips of this kind are less widely used today than they used to be, but logic itself remains fundamental to all computing devices. So let’s go deeper, now, into that world, to learn how it works—and have some fun.

Experiment 15: Telepathy Test

This first logic project seems ridiculously simple. All you need are four pushbuttons, a couple of chips, and an LED. As we delve deeper, though, you’ll find that it’s not quite so simple after all.

The ostensible purpose of this experiment is to test your capability for extrasensory ...