Eva-navigation-unit

A DIY car head-unit interface for SBCs and Linux tablets. It aims to be a fully-featured head-unit replacement for older cars that either never had one or have a factory unit worth ripping out. The theme and aesthetic are inspired by 90s cyberpunk anime and the Evangelion universe.

More screenshots

The current target hardware is a jailbroken Nintendo Switch OLED running L4T Fedora, but the goal is to not gatekeep the project to a single hardware configuration — hence the growing number of configuration options available to tailor the experience to whatever screen/SBC you're running it on.

Warning

This project is mostly vibe-coded and is still in early development and testing. Expect rough edges, half-finished features, and breaking changes. It is not yet ready to be relied on as your car's only head unit.

Features

• Android Auto
  • USB
  • Wireless (WIP)
    • Automatically sets up the access point using the selected backend (hostapd or NetworkManager)
• Live spectrum analyzer for audio visualization
  • Selectable analyzer theme and shape
• Bluetooth & media control
• Embeded media player
  • Spotify connect
  • Subsonic
  • mpc/local file
• Audio Equilizer & effects
• Nice 90s wireframe-style interface
  • Multiple color themes
• OBD2
  • Display car telemetry in retro-style gauges and segment displays
  • Send back car telemetry to AA (rpm, speed, fuel tank...)
  • Show OBD2 engine faults
• Controller/GPIO input for integration with native car headunit buttons
• Multi-point touch input for AA

Build Prerequisites (Fedora)

Install required system libraries:

sudo dnf install \
  gcc gcc-c++ make pkgconf-pkg-config perl \
  clang clang-devel \
  protobuf-compiler \
  fontconfig-devel \
  libxcb-devel libxkbcommon-devel libxkbcommon-x11-devel \
  wayland-devel mesa-libGL-devel mesa-libEGL-devel \
  openssl-devel \
  alsa-lib-devel \
  dbus-devel \
  nasm

# Runtime dependencies
sudo dnf install bluez NetworkManager pipewire-pulseaudio

Group	Packages	Required by
Build tools	gcc, gcc-c++, make, pkgconf-pkg-config, perl	C/C++ compilation, pkg-config
Crypto	clang, clang-devel	aws-lc-rs bindgen
Protobuf	protobuf-compiler	android-auto build script
UI	fontconfig-devel, libxcb-devel, libxkbcommon-devel, libxkbcommon-x11-devel, wayland-devel, mesa-libGL-devel, mesa-libEGL-devel, openssl-devel	Slint (windowing, fonts, OpenGL)
Audio	alsa-lib-devel	cpal (ALSA)
D-Bus	dbus-devel	zbus, NetworkManager client
Video	nasm	OpenH264 asm optimizations
Runtime	bluez	Bluetooth (wireless transport)
Runtime	NetworkManager	Wi-Fi hotspot
Runtime	pipewire-pulseaudio (or pulseaudio)	Audio capture for the spectrum analyzer/visualizer

Build

cargo build --release

Installing the Wi-Fi hotspot service (for Android Auto wireless)

This step is only required when using the hostapd hotspot backend. If you're using the NetworkManager backend instead, you can skip it.

Android Auto wireless needs a privileged Wi-Fi access point. This is handled by a small systemd service + polkit rule so the head-unit app itself never needs to run as root:

cd deploy/eva-hotspot
sudo ./install.sh <username>             # one-time, needs root; <username> is
                                          # the account that runs eva-ui

# verify polkit works WITHOUT sudo:
systemctl start eva-hotspot.service && systemctl is-active eva-hotspot.service
systemctl stop  eva-hotspot.service

Then set hotspot_backend = 1 (or the desired backend) in eva-ui's config.toml. See deploy/eva-hotspot/install.sh and deploy/eva-hotspot/hotspot.env for the available options (SSID/PSK, channel, country code, DHCP range).

Run

cargo build --release
DISPLAY=:0 ./target/release/eva-navigation-unit &> eva-ui.log   # NOTE: no sudo

Configuration

eva-navigation-unit is configured via a TOML file, environment variables, and CLI flags. See docs/configuration.md for the config file location, precedence rules, and the full list of options.

Thanks

This project would not be possible without uglyoldbob/android-auto, which provides the Android Auto server implementation.