LibAuto

LibAuto is an Android USB-host head-unit app that runs Android Auto projection on tablets and aftermarket Android head units. It speaks Android Open Accessory / Android Auto over USB, decodes the phone-provided media stream locally, forwards touch/media controls back to the phone, and presents a fullscreen in-car UI.

This project is not affiliated with, endorsed by, sponsored by, or connected to Google, Android, Android Auto, or any vehicle/head-unit vendor. Android, Android Auto, Google, and other product names are trademarks of their respective owners.

Current Status

LibAuto is usable as an experimental head-unit app. The tested happy path is:

- USB Android Auto starts from a connected Android phone. - The app can automatically enable AOAP/accessory mode and start projection. - Video, audio, touch, two-finger gestures, and media keys are implemented. - GPS-backed vehicle speed and basic fake-car sensors are sent when requested. - The UI is fullscreen and optimized for 1024x600, 16:10 tablet displays, and common 16:9 projection sizes. - Experimental wireless Android Auto work is present in the codebase, but the launcher controls are hidden until the Bluetooth/Wi-Fi bootstrap is reliable enough for testing.

This is still not a certified Android Auto receiver. Expect device-specific behavior, especially on heavily modified Android head units.

Compatible Platforms

Known working:

- HarmonyOS 4.2 / Android 12 tablet, Snapdragon 865, USB host mode. - Android aftermarket head units that can install normal APKs and expose USB host devices to apps.

Designed for:

- Android 8.0+ (minSdk 26). - Android 15 target (targetSdk 35) for the standard/Play build. - Legacy target (targetSdk 28) for sideload-only head-unit builds that reject modern APK metadata. - armeabi-v7a and arm64-v8a devices. - Screens around 800x480, 1024x600, 1280x720, 1920x1080, and native-aspect scaled modes.

Requirements:

- USB host support. - A cable and port that expose the phone as a USB device to Android. - Runtime permissions for USB, microphone, and location if you want voice/GPS-backed vehicle data. - A phone with Android Auto installed and enabled for wired projection.

Features

- One-tap session start from a connected USB device list. - Optional autoconnect when exactly one USB device is present. - Projection quality options: 480p, 720p, 1080p. - Native-aspect option for non-16:9 head-unit screens. - Local video rendering with letterbox/fill handling. - Touch and two-pointer gesture forwarding. - Learnable hardware/media key forwarding for play, pause, stop, next, previous, rewind, fast-forward, voice, call, and related controls. - Audio playback through Android AudioTrack. - Microphone channel support for Android Auto voice input. - Sensor channel support for driving status, night mode, GPS speed, gear, and parking brake. - Conservative file logging to avoid excessive NAND writes on head units. - Session reset on disconnect/replug so stale framebuffers do not block the next run.

License

GNU General Public License v3.0