Inside, an Arduino Nano is hooked up to a series of WS2812b LEDs. The LEDs are flashed in time with the heartbeat of the person holding the heart, thanks to a MAX30102 heartbeat sensor.

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.

WS2812B & Arduino Earlier we controlled LED matrixes, strips and other complex LED projects bundled with countless interconnected wires with the help of multiplexers and shift registers.