The goal is for this to be a Phoenix application running on a Raspberry Pi to function as a simple music box for kids.

• Music Player Daemon - Headless music player for Linux
• Phoenix LiveView - Instantaneous web UI without writing JavaScript
• Nerves - Creating Elixir projects as full-blown firmware images such as for booting a Raspberry Pi
• Elixir Circuits - Elixir SDK for GPIO and SPI for managing the buttons and RFID reader

• RFID cards trigger playing songs or playlists
• Web interface to manage playlists, upload new music, pair new cards
• Buttons to control playback

• app/ - Phoenix web application
• mpd/ - Custom lightweight build of mpd
• rpi/ - Scripts to configure a fresh install of Raspbian. May be obviated by using Nerves

This application is Dockerized. With Docker and docker-compose installed:

docker-compose build

On Linux we can mount /dev/snd in the Docker container and mpd can directly use our host system's sound output.

macOS doesn't have /dev/snd or ALSA, so we configure mpd to output via an HTTP/Shoutcast server. Then on our macOS host we can use iTunes or VLC to connect to the stream.

Use start_env.sh to automatically pick the correct configuration.

./start_env.sh

Put any music files you want into mpd/music and they'll be detected automatically by mpd.