FastLED for the web

This project compiles the embedded C++ FastLED library and some of the examples to Web Assebly (WASM) and uses the browser as a virtual RGB LED display.

See the demo here

How does it work?

I did some minor changes to the FastLED code base so it compiles without any embedded/device specific code (MR is pending).

Then I slightly modified the examples so the actual rendering is just a function which writes to an array of CRGB values (smiliar to before, but not using global variables). For an example look here.

The old Arduino style setup and loop function are no longer needed, because we are not interfacing real hardware.

The emscripten compiler now is able to compile everything into Web Assembly (WASM), which is a binary instruction format that can be interpreted by modern browsers.

On the frontend-side (browser), some hand crafted JavaScript now calls the WASM-implemented FastLed-rendering function, which results in an array of RGB values. These values are then painted into a HTML5-canvas as a matrix or stripe.

With a similar approach, I made an interactive playground for my JLed library. I exported the whole JLed class to Javascript, which allows to use the JLed C++API from Javascript.

How to use it in your own project

tbd

Local testing

• install emscripten
• run make && make server
• visit http://localhost:8000

Author & License

(c) Copyright 2020-2021 by Jan Delgado, License: MIT