The timer controller board has a PIC micro, some buttons, potentiometers, LED’s and an IR receiver. ... onto which he plugged a small board containing an Arduino Nano and a few components.

Arduino has shrunk the UNO R4 with the Arduino Nano R4 board equipped with the same 48 MHz Renesas RA4M1 32-bit Arm ...

The build is open-source, and designed to work with strings of 60, 120, or 180 WS2812B LEDs. An Arduino Nano is charged with running the show, capturing audio via its analog-to-digital converter.