Rpi-SK6812-ws2812b-RGBW-http-server

This is an express server that exposes an API to drive SK6812/ws2812b RGBW LED strips on a Raspberry Pi

Hardware Install

1. Plug the +5V and GND in an external power supply.

2. Plug the DATA and GND in your Raspberry Pi.

3. The default data pin is GPIO18 (which is #12 on the circuit board). You can change it in the .env file.

Software Install

You'll need some dependencies for this. On Debian, Ubuntu, etc. you can install them with

sudo apt install build-essential python3

Then, just run the server with:

cp .env.dist .env # Copy and edit environment variables
npm install
sudo npm start

Supported LED_TYPE

// 4 color R, G, B and W ordering
"sk6812-rgbw"
"sk6812-rbgw"
"sk6812-grbw"
"sk6812-gbrw"
"sk6812-brgw"
"sk6812-bgrw"

// 3 color R, G and B ordering
"ws2811-rgb"
"ws2811-rbg"
"ws2811-grb"
"ws2811-gbr"
"ws2811-brg"
"ws2811-bgr"

// predefined fixed LED types
"ws2812"
"sk6812"
"sk6812w"

API

HTTP

Do an HTTP POST with this JSON body:

{
    "colors": [
        { "r": 255, "g": 255, "b": 255, "w": 255 },
        { "r": 255, "g": 0, "b": 0, "w": 0 },
        { "r": 0, "g": 255, "b": 0 },
        { "r": 0, "g": 0, "b": 255 },
        { "r": 0, "g": 0, "b": 0, "w": 255 }
    ]
}

Or this JSON body (WWRRGGBB or RRGGBB):

{
    "colors": [
        "FF995522",
        "FF9955",
        "FF995500",
    ]
}

Note that the "white" value is optionnal. It will default to 0. With as many element in the array as your LED strip is. Usually 30, 60 or 120 LED/m.

UDP

The UDP server runs on port 13334 by default.

First byte is header: 0x03 for RGB, 0x04 for RGBW. Rest is payload, each byte is a color value.

For instance:

Head R    G    B    R    G    B   
0x03 0xFF 0x99 0x55 0xFF 0x99 0x55

Head W    R    G    B    W    R    G    B   
0x04 0x22 0xFF 0x99 0x55 0x22 0xFF 0x99 0x55

You can also send a JSON on UDP. If the first character is a curly bracket ({) it will behave like the HTTP API.

{"colors": ["9955CC", "FF9955CC"]}

curl Example

curl -X POST \
  http://<raspberry-ip-address>:13334 \
  -H 'Content-Type: application/json' \
  -d '{ "colors": [{"r": 255, "g": 255, "b": 255, "w": 255}]}'