Simple Pitch Follower

摘要

The idea for this project came when browsing the Elektor Archives. In 301 Circuits, the second book in the popular Elektor '300' series of books we came across project no. 14 entitled Easy Music. The article claims that the little circuit is capable of tracking a melody whistled at its input and then adds a second voice to it. Its output stage consists of a basic power amplifier and a loudspeaker. When asked to develop something similar today the first thing we would do is throw an Arduino at it, and that's exactly what we did. In the circuit presented here we have combined the old and the new. The old is the input stage from the Easy Music project, the new is either an Arduino Uno or an AVR Playground running pitch tracking software. The schematic shown in Figure 1 is the result.