Brilliant LED Projects: 20 Electronic Designs for Artists, Hobbyists, and Experimenters

CHAPTER 15Basic LED Matrixand POV Concepts: How toBuild a Three-Digit Counter

THE PROJECTS IN THE PRECEDING TWO PARTS OF THIS book demonstrate how to create some interesting effects using various types of LEDs either by illuminating them or flashing them in a particular sequence. The projects presented in this third and final part of the book show you how to build circuits that create “persistence of vision” (POV) effects. This chapter first explains how the POV effect works and briefly describes LED multiplexing circuit principles. The chapter’s project then demonstrates how a typical matrix circuit can be made to produce the POV effect by using three seven-segment displays to create a three-digit counter, shown in Figure 15-1. You could house ...