Underglow

Underglow and sideglow/side-lighting is decorative lighting out of one or more of a keyboard's sides using LEDs, most often RGB LEDs. The terminology is floating between referring to how the LEDs are mounted and to how the light is emitted out of the keyboard's. Parts of the case are often made of frosted plastic to diffuse the light. In some keyboards the light is designed to project more onto the user's desk than to be visible directly. The LEDs are often configured to show a slowly shifting colour gradient.

Custom keyboards tend to use down-facing RGB LEDs that are variants of the WS2811/WS2812 and SK6812/SK6805. These are supported by the QMK firmware and are addressable over a PWM-based interface that requires only one pin on the keyboard controller for control of them all.

Some commercial keyboards instead use right-angle LEDs on the PCB's perimeter.

External links

• MickMake on Youtube: How to use WS2812 LEDs - A simple Wiffy counter in GoLang // Project
• QMK documentation: RGB Lighting