RGB/Underglow/NeoPixel

Want your keyboard to shine? Add some lights!

CircuitPython

This does require the NeoPixel library from Adafruit. It is part of the Adafruit CircuitPython Bundle. Simply put this in the “root” of your CircuitPython device. If unsure, it’s the folder with main.py in it, and should be the first folder you see when you open the device.

Currently we support the following addressable LEDs:

WS2811, WS2812, WS2812B, WS2812C, etc.
SK6812, SK6812MINI, SK6805

Color Selection

KMK uses Hue, Saturation, and Value to select colors rather than RGB. The color wheel below demonstrates how this works.

Changing the Hue cycles around the circle. Changing the Saturation moves between the inner and outer sections of the wheel, affecting the intensity of the color. Changing the Value sets the overall brightness.

Enabling the extension

The only required values that you need to give the RGB extension would be the board pin for the data line, and the number of pixels/LED’s. If using a split keyboard, this number is per side, and not the total of both sides.

import board
from kmk.extensions.RGB import RGB

rgb = RGB(pixel_pin=board.GP14, num_pixels=27)
keyboard.extensions.append(rgb)

[Keycodes]

Key	Aliases	Description
`KC.RGB_TOG`		Toggles RGB
`KC.RGB_HUI`		Increase Hue
`KC.RGB_HUD`		Decrease Hue
`KC.RGB_SAI`		Increase Saturation
`KC.RGB_SAD`		Decrease Saturation
`KC.RGB_VAI`		Increase Value
`KC.RGB_VAD`		Decrease Value
`KC.RGB_ANI`		Increase animation speed
`KC.RGB_AND`		Decrease animation speed
`KC.RGB_MODE_PLAIN`	`RGB_M_P`	Static RGB
`KC.RGB_MODE_BREATHE`	`RGB_M_B`	Breathing animation
`KC.RGB_MODE_RAINBOW`	`RGB_M_R`	Rainbow animation
`KC.RGB_MODE_BREATHE_RAINBOW`	`RGB_M_BR`	Breathing rainbow animation
`KC.RGB_MODE_KNIGHT`	`RGB_M_K`	Knight Rider animation
`KC.RGB_MODE_SWIRL`	`RGB_M_S`	Swirl animation

Configuration

Define	Default	Description
`rgb.num_pixels`		The number of LEDs connected
`rgb.rgb_order`	`(1, 0, 2)`	The order of the pixels R G B, and optionally white. Example(1, 0, 2, 3)
`rgb.hue_step`	`10`	The number of steps to cycle through the hue by
`rgb.sat_step`	`17`	The number of steps to change the saturation by
`rgb.val_step`	`17`	The number of steps to change the brightness by
`rgb.hue_default`	`0`	The default hue when the keyboard boots
`rgb.sat_default`	`255`	The default saturation when the keyboard boots
`rgb.val_default`	`255`	The default value (brightness) when the keyboard boots
`rgb.val_limit`	`255`	The maximum brightness level

Built-in Animation Configuration

Define	Default	Description
`rgb.breathe_center`	`1.5`	Used to calculate the curve for the breathing animation. Anywhere from 1.0 - 2.7 is valid
`rgb.knight_effect_length`	`4`	The number of LEDs to light up for the “Knight” animation

Functions

If you want to create your own animations, or for example, change the lighting in a macro, or a layer switch, here are some functions that are available.

Function	Description
`rgb.set_hsv_fill(hue, sat, val)`	Fills all LED’s with HSV values
`rgb.set_hsv(hue, sat, val, index)`	Sets a single LED with HSV value
`rgb.set_rgb_fill((r, g, b))`	Fills all LED’s with RGB(W) values
`rgb.set_rgb((r, g, b), index)`	Set’s a single LED with RGB(W) values
`rgb.increase_hue(step)`	Increases hue by a given step
`rgb.decrease_hue(step)`	Decreases hue by a given step
`rgb.increase_sat(step)`	Increases saturation by a given step
`rgb.decrease_sat(step)`	Decreases saturation by a given step
`rgb.increase_val(step)`	Increases value (brightness) by a given step
`rgb.decrease_val(step)`	Decreases value (brightness) by a given step
`rgb.increase_ani()`	Increases animation speed by 1. Maximum 10
`rgb.decrease_ani()`	Decreases animation speed by 1. Minimum 10
`rgb.off()`	Turns all LED’s off
`rgb.show()`	Displays all stored configuration for LED’s

Direct variable access

Define	Default	Description
`rgb.hue`	`0`	Sets the hue from 0-255
`rgb.sat`	`255`	Sets the saturation from 0-255
`rgb.val`	`255`	Sets the brightness from 0-255
`rgb.reverse_animation`	`False`	If true, some animations will run in reverse. Can be safely used in user animations
`rgb.animation_mode`	`static`	This can be changed to any modes included, or to something custom for user animations. Any string is valid
`rgb.animation_speed`	`1`	Increases animation speed of most animations. Recommended 1-5, Maximum 10.

from kmk.extensions.rgb import AnimationModes
rgb = RGB(pixel_pin=rgb_pixel_pin,
        num_pixels=27
        val_limit=100,
        hue_default=0,
        sat_default=100,
        rgb_order=(1, 0, 2),  # GRB WS2812
        val_default=100,
        hue_step=5,
        sat_step=5,
        val_step=5,
        animation_speed=1,
        breathe_center=1,  # 1.0-2.7
        knight_effect_length=3,
        animation_mode=AnimationModes.STATIC,
        reverse_animation=False,
        refresh_rate=60,
        )

Hardware Modification

To add RGB LED’s to boards that don’t support them directly, you will have to add a 3 wires. The power wire will run on 3.3v or 5v (depending on the LED), ground, and data pins will need added to an unused pin on your microcontroller unless your keyboard has specific solder points for them. With those 3 wires connected, set the pixel_pin as described above, and you are ready to use your RGB LED’s/NeoPixel.

Troubleshooting

Incorrect colors

If your colors are incorrect, check the pixel order of your specific LED’s. Here are some common ones.

WS2811, WS2812, WS2812B, WS2812C are all GRB (1, 0, 2)
SK6812, SK6812MINI, SK6805 are all GRB (1, 0, 2)
NeoPixels will vary depending on which one you buy. It will be listed on the product page.

Lights don’t turn on

Make sure that your board supports LED backlight by checking for a line with PIXEL_PIN. If it does not, you can add it to your keymap. If you added the LED’s yourself, you will also need to set num_pixels to the number of installed LED’s in total.

Alternate LED chipsets

Not all RGB LEDs are compatible with NeoPixels. To support these, the RGB extension accepts an instance of a Pixelbuf-compatible object as an optional parameter. If supplied, pixel_pin is ignored and the supplied Pixelbuf is used instead of creating a NeoPixel object. The RGB extension will figure out LED count from the pixel buffer length if not passed explicitly.

This works easily with APA102 (“DotStar”) LEDs, but for most other RGB LED chipsets you will need to provide a wrapper to match the expected interface.

A simple example using APA102:

import adafruit_dotstar
from kmk.extensions.RGB import RGB
from kb import rgb_pixel_pin  # This can be imported or defined manually

_LED_COUNT=12
pixels = adafruit_dotstar.DotStar(board.SCK, board.MOSI, _LED_COUNT)

rgb = RGB(pixel_pin=None, pixels=pixels)
keyboard.extensions.append(rgb)

Multiple PixelBuffer

Similar to alternate drivers, the RGB module supports passing multiple Pixelbuf objects as an iterable.

from kmk.extensions.RGB import RGB

pixels = (
    Neopixel(...),
    DotStar(...),
    CustomPixelBuf(...)
)

rgb = RGB(pixel_pin=None, pixels=pixels)
keyboard.extensions.append(rgb)