Lifx

A Client for Lifx LAN API

Automatically discover and control all of your Lifx lightbulbs.

Use

1. git clone https://github.com/NationalAssociationOfRealtors/lifx.git
2. mix do deps.get, deps.compile
3. iex -S mix
4. iex(4)> Lifx.Client.start

For testing purposes it includes a small web frontend that's available at http://localhost:8800

The web interface currently controls all lights on the network.

You can disable the web interface by setting :lifx, tcp_server: false in your applications config file

Explanation

As long as you are on the same subnet as your lightbulbs, you should see some information in stdout about devices being discovered

Starting Device
%Lifx.Device.State{
    group: %Lifx.Protocol.Group{
        id: [],
        label: nil,
        updated_at: 0
    },
    host: {192, 168, 1, 118},
    hsbk: %Lifx.Protocol.HSBK{
        brightness: 100,
        hue: 120,
        kelvin: 4000,
        saturation: 100
    },
    id: :"193196534887376",
    label: nil,
    location: %Lifx.Protocol.Location{
        id: [],
        label: nil,
        updated_at: 0
    },
    port: 56700,
    power: 0,
    rx: 0,
    signal: 0,
    tx: 0
}

What's shown here is the initial state of the bulb. Shortly after the bulb is discovered it will gather the state information, and update it every 5 seconds.

Architecture

Lifx.Client is a small UDP server running on a randomly selected available port. It is the main interface for sending and receiving messages. As a new device is discovered a process is spawned and it's state represents the given device.

Every 5 seconds the device process queries itself for updated state information. The updated state is then broadcast (using notify) over Lifx.Client.Events event bus. Anyone can add a handler to the event bus to handle updated device state by calling Lifx.Client.add_handler. See Lifx.Handler for an example implementation of an event handler.

There's a good chance that by the time you've added your handler to Lifx.Client that device discovery has already happened. Luckily Lifx.Client also keeps a list of the known devices in it's state. You can return the currently known devices by calling Lifx.Client.devices which returns something similar to this.

[
    %Lifx.Device.State{
        group: %Lifx.Protocol.Group{
            id: <<251, 202, 127, 40, 82, 243, 115, 230, 221, 64, 134, 187, 206, 118, 102, 156>>,
            label: "Lab",
            updated_at: 13888846944200582420
        },
        host: {192, 168, 1, 118},
        hsbk: %Lifx.Protocol.HSBK{
            brightness: 6701,
            hue: 53768,
            kelvin: 4000,
            saturation: 65535
        },
        id: :"193196534887376",
        label: "Bulb 2",
        location: %Lifx.Protocol.Location{
            id: <<205, 66, 137, 157, 220, 168, 133, 96, 147, 254, 0, 111, 52, 160, 229, 6>>,
            label: "CRT Lab",
            updated_at: 13836094609682883860
        },
        port: 56700,
        power: 65535,
        rx: 172830474,
        signal: 9.999999747378752e-6,
        tx: 1031638823
    },
    %Lifx.Device.State{
        group: %Lifx.Protocol.Group{
            id: <<251, 202, 127, 40, 82, 243, 115, 230, 221, 64, 134, 187, 206, 118, 102, 156>>,
            label: "Lab",
            updated_at: 13868661424052266260
        },
        host: {192, 168, 1, 60},
        hsbk: %Lifx.Protocol.HSBK{
            brightness: 6701,
            hue: 53768,
            kelvin: 4000,
            saturation: 65535
        },
        id: :"204217420968912",
        label: "Bulb 1",
        location: %Lifx.Protocol.Location{
            id: <<205, 66, 137, 157, 220, 168, 133, 96, 147, 254, 0, 111, 52, 160, 229, 6>>,
            label: "CRT Lab",
            updated_at: 9281461546755319060
        },
        port: 56700,
        power: 65535,
        rx: 178000365,
        signal: 1.2589248399308417e-6,
        tx: 1032173655
    }
]

Lifx.Client also provides a function to set bulb color to all devices currently on the network. It uses a broadcast packet to accomplish this.

Lifx.Protocol handles all protocol related functions, parsing and creating packets as well as payloads.

In order to communicate with a single bulb, in a network that may contain multiple devices you would use the Lifx.Device interface Lifx.Device.set_color(pid, %Lifx.Protocol.HSBK{}, duration) where pid is Lifx.Device.State.id