Over the summer [ElectroSmash] put the finishing touches on the Arduino Audio Meter, a shield for the Arduino Uno that visualizes various aspects of an incoming audio signal on a set of four 8×8 ...

USB 2.0 over USB Type C connector Power 3.7/4.2 V Lithium Polymer Rechargeable Battery or USB / External 5 V Powered ESP32 and Audio Codec can be placed into low power modes under software control ...

Naturally, there are some computational constraints when using an Arduino for DSP, though it’s up to you whether this is a frustrating fact, or an opportunity to write some nicely optimised code.