LSDG Light Site

This is a simple webpage for controlling the light controller (a Raspberry Pi) for our lighting show. It's optimized for a phone screen, since it's more likely that people will be using phones to control it, rather than laptops.

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TODO:

• Test rPi re-connection.
• Test attempted rPi connection with an established rPi connection.
• Look up Album art when getting the song list.
• Check song simulation; it appears to always keep simulating the song, leading to ever-increasing speeds.
• Base ability to delete songs off local cookie.
• Fix bug where the client attempts to get the current status, but there's no song list, so the server blows up.
• Needs to remember previous position and return to it once it empties the queue.
• Add RSA-based challenge for rPi authentication.
• Add slide transition when song changes.

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Raspberry Pi Communication

The Raspberry Pi (rPi) connects to the site, and then sends a special authenticate message. This starts an authentication process that allows us to be sure that the rPi is actually our rPi, and no one's attempting to spoof it.

After that, there's a very limited lexicon the rPi and website can speak to each other. Mostly it's event based from the rPi, and command based from the website.

Namespaces

The rPi communication will happen in a namespace called rpi, and the client side communication of the website will happen in a namespace called songctrl.

The rpi namespace

Authentication

The rPi will sign a challenge message sent by the site. Details TBD.

Raspberry Pi Events

These are events sent from the rPi to the website.

song finished Event

{
    song: "song_filename.mp3"
}

This event is fired whenever the rPi finished playing a song. The song parameter is the filename of the song that finished playing.

song started Event

** This event may not be useful. **

{
    song: "song_filename.mp3"
}

This event is fired whenever the rPi starts playing a song. The song parameter is the filename of the song that finished playing.

Raspberry Pi Commands

These are commands send from the website to the rPi.

get status Command

No data

Asks the rPi for it's current status.

Reply

{
    playing: "song_filename.mp3" | "none"
}

The rPi is either playing a song, in which case playing will be the filename of the song, or it isn't playing anything, in which case playing will be "none".

list songs Command

No data

This asks the rPi to give us a list of all the songs it currently knows how to play. We expect the songs to be in the format specified in the response.

Reply

{
    songs: [
        {
            title: "Winter Wizard (Instrumental)",
            artist: "Trans-Siberian Orchestra",
            duration: 185,
            filename: "TSO - Winter Wizard.mp3"
        },
        ...
    ]
}

The rPi is expected to respond with a list, either empty or populated with song objects, as specified above.

play next Command

{
    song: "song_filename.mp3"
}

This queues up the next song for the rPi to play as soon as it finished playing the current song. The song parameter is the filename of the song to play next.

Reply

{
    confirm: true
}

This is just a simple confirmation message that lets the website know the song has actually started playing, so it should start updating it's display.

stop Command

No data

Tells the rPi to stop playing after the current song.

Reply

{
    confirm: true
}

This is just a simple confirmation message that lets the website know once the rPi has finally stopped.

stop immediately Command

No data

Tells the rPi to stop playing immediately.

Reply

{
    confirm: true
}

This is just a simple confirmation message that lets the website know once the rPi has finally stopped.

The songctrl namespace

API TBD.