The TAB Book of Arduino Projects: 36 Things to Make with Shields and Proto Shields

CHAPTER 15

Spectrum Display

This project uses an Arduino to control a multicolor LED matrix, displaying the real-time frequency spectrum of an audio signal (Figure 15-1).

FIGURE 15-1 Audio spectrum display.

This project would make a nice addition to any audio system. Displaying the spectrum of an audio signal involves splitting the signal into a number of frequency bands and measuring the magnitude of the signal at each band. The human ear (or, rather, the young human ear) is usually assumed to be able to detect sound waves between 20 Hz and ...