aulos

An automotive media interface.

⚠️ Very much a work in progress!

This has not been extensively tested and many things probably don't work.

Audio playback is handled by cmus and it features a clock via tock and a visualizer by vis (cli-visualizer), wrapped up and served to your Raspberry Pi via buildroot.

Intended to be run on a Euro-spec 2017 Ford Focus, but can probably be adapted to work with other makes and models.

Directories and Files

• buildroot : Contains the downloaded buildroot source files (not included in this repo)
• external : Contains the aulos-specific buildroot configs and packages
• controller.ino : Arduino code to translate CANBUS messages to key presses
• README.md : This file
• setup.sh : A script that stages the buildroot environment
• update-library.sh : A script that copies new music to aulos and builds the library playlist file for cmus

Prerequisites & Notes

This system is intended to be run in an automotive environment, and so the primary needs were determined to be:

• Speed at which the system would boot
• Resiliency in case of a power failure event
• Quality audio playback

Additionally, keyboard shortcuts for cmus are not keyboard-friendly given that interaction is through the media keys on the car audio system.

⚠️ NOTE

There is no network stack and the kernel has been stripped of things considered to be "non-essential" (drivers, mostly).

Hardware List

• RaspberryPi 4B 8GB RAM
• HiFiBerry DAC2 HD
• KKSB Tall Aluminium Case for Raspberry Pi 4
• Power + RTC HAT for Raspberry Pi
  • CR1220 3V Lithium Coin Cell Battery
• Pure Copper 4-Piece Heatsink Set for Raspberry Pi 4
• Noctua NF-A4x10 5V Fan
• Waveshare 7inch IPS/QLED Integrated Display, 1024 × 600

Building

1. Clone this repository git clone https://github.com/ohitsdylan/aulos
2. Change directories into the repo cd aulos
3. Run the setup script ./setup.sh

Principle Functionality

1. The Pi boots and logs into the aulos user automatically
2. A script, start-aulos.sh, in /etc/profile.d runs and:
   1. Starts tmux and creates three panes
   2. In pane one, cmus is started
   3. In pane two, tock is started
   4. In pane three, vis is started
   5. Focus is switched back to pane one.
3. Interaction with the system is done via a CANBUS media interface. Button presses are converted from CANBUS data to HID key presses and sent to the Pi, which are interpreted by cmus.
4. Media is stored in /home/aulos/music and is read-only.

TODO

• Test running system as a RAM disk
  • Or maybe toggle the "mount read-write" setting in buildroot
• Add photos and screenshots
• Configure RTC clock
• Create a fakeroot script to modify some directory permissions
• See if autologin script works for aulos user
• Setup psplash