# Fledex

Fledex is a small [Elixir](https://elixir-lang.org/) library It really is intended for educational purposes.
It is written for a RaspberryPi Zero W running [Nerves](https://nerves-project.org/) especially with a [Nerves-Livebook](https://hexdocs.pm/nerves/getting-started.html#nerves-livebook). 
The intent of the library is to simplify the programming of a programmable LED strip (currently based on a [WS2801 chip](https://cdn-shop.adafruit.com/datasheets/WS2801.pdf)) and thereby to make it accessible even for kids.

The idea is to introduce similarly easy concepts for the programming of LEDs as [SonicPi](https://sonic-pi.net/) did for music. The library was developped in collaboration with my son and hopefully we can push it to become better over time. For my son the goal will be to connect the LEDs to some music and to animate the LEDs depending on the beat.

Quite a lot of inspiration came from the [FastLED project](http://fastled.io/) and quite a few of their functions got reimplemented in Elixir. If you look at the implementation of some of those functions you might want to look at their comments.

## Installation

** TODO: ensure the links to hex & hexdocs are correct **

The library is [available in Hex](https://hex.pm/docs/publish), the package can be installed
by adding `fledex` to your list of dependencies in `mix.exs`:

```elixir
def deps do
  [
    {:fledex, "~> 0.1.0"}
  ]
end
```

Once in you have installed the library and run your usual `mix deps.get` you can start the LedDriver Server by calling:
```elixir
config = %{
  # here comes your configuration
}
{:ok, pid} = LedsDriver.start_link(config)
```

The LedsDriver should have quite reasonable defaults to get you started (a LoggerDriver is used by default)

Your interaction with the LedDriver should mainly happen through the Leds module. To set the first 3 LEDs (of a 50 LED strip) to red, green and blue you would do the following (here the [color names](https://www.ditig.com/256-colors-cheat-sheet) are used, but you could have used the hex values `0xFF0000`, `0x00FF00`, and `0x0000FF` too):
```elixir
LedsDriver.define_namespace(:default)
Leds.new(50)
  |> Leds.light(:red)
  |> Leds.light(:green1) 
  |> Leds.light(:blue)
  |> send() # :default namespace is used as default
```
All other LEDs would be set to off

## Livebook
You can find some [livebooks](livebooks/README.md) files that show you how to use the library in a notebook (with and without hardware). You should be able to do most of your development on a computer (emulating the LED strip with a KinoDriver) before adjusting it to the real hardware (with the SpiDriver). On real hardware you can even run it with serveral drivers at the same time.

## Known Limitations
If you want to run this library in nerves-livebook, you currently have to copmile your own livebook with the library included in your `mix.exs` file, since you can't add any libraries that are not already bundled.