As Alex Rex explains, music and sound inspire many people, including himself. For his AURA — Audio Reactive Artistry — project, he wanted to extend the experience of a piano concert into the visual space, moving objects such as wooden rods according to volume and frequency.
To accomplish this feat, he’s using a microcontroller to read the sound levels at different frequencies, then output corresponding signals to a number of motors. As a bit of a twist, he outlines how to do so in two formats on the project page. Setup A uses an Arduino Uno and SparkFun Spectrum shield to analyze audio signals, then pass corresponding movements along to 360° micro servo motors. As a bit of a budget configuration, it can be built for around €100 , or just under $110 USD.
Setup B, however, employs a Teensy 3.5 to enables users to specify frequency ranges and NEMA 17 stepper motors for movement. These steppers are more powerful and precise than the little servos, and with a TMC2208 driver they are also very quiet — perfect for use in sound installations. With this better performance comes a higher price of roughly €250 or about $270 USD.
Regardless of how you construct it, the Setup B-style installation looks intriguing in the video below — a forest of wooden rods swaying to the music of a clarinet performance.