Thanks to the Teensy Audio Library, palmerr used a Teensy 4.0 to particularly stunning effect with his CS42448-based AudioToy 8×8 channel modular mixer.

This pro-grade piece of kit features fully balanced, software gain-controlled line/instrument inputs and 600 ohm/+8dBm outputs, with combo XLR/TRS sockets whose insertion status can be remotely read over I2C. An ESP32 allows remote control via Wi-Fi, while  WS2812B LED strips indicate channel levels.

Complete hardware details for its component modules, as well as a user manual, can be found on GitHub.