binarybrain / virtual-led-server

Create a web server that show virutal LEDs in your browser

Virtual LED Server

⚠️ DEPRECATED ⚠️

This whole tool is now part of https://github.com/BinaryBrain/Rpi-SK6812-ws2812b-RGBW-http-server

---

This is an express server that exposes an API to drive virtual RGBW LED strips in your browser.

It can be used as a dummy server for Rpi-SK6812-ws2812b-RGBW-http-server.

Software Install

Run the server with:

npm install
npm start

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:

{
    "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 R    G    B    W    R    G    B    W   
0x04 0xFF 0x99 0x55 0x22 0xFF 0x99 0x55 0x22

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

{"colors": ["FF9955", "FF9955FF"]}

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}]}'

What we send to ws281x lib

Each line is an UInt32.

RGBW

2^ | 3 2 1 0
i+ | - 0 1 2
---+--------
0  | - r g b
1  | - w r g
2  | - b w r
3  | - g b w
4  | - r g b
5  | - w r g
6  | - b w r
7  | - g b w

GRBW

2^ | 3 2 1 0
i+ | - 0 1 2
---+--------
0  | - g r b
1  | - w g r
2  | - b w g
3  | - r b w
4  | - g r b
5  | - w g r
6  | - b w g
7  | - r b w