Open Headunit

An Android app that turns your Android tablet or phone into an Android Auto receiver.

A revived version of the original headunit project by Michael Reid.

Important

Android Auto 17.4 and newer breaks almost all third-party wireless triggers, including Self-Mode and the automated launch via Wireless Helper. Google introduced internal changes preventing projection from launching automatically without the native developer server or hardware dongles. On AA 17.4 and above, use one of the four options described below.

Features

Wired USB connection

- Connect your phone to the tablet running Open Headunit via USB cable. - Set your phone to Host Mode if necessary and select Android Auto. - Click the USB button in Open Headunit, find your phone, and allow the connection. - Click your phone in the list and wait for Android Auto to start.

Wireless connection options

- USB Wireless Android Auto Dongle (most reliable): a standard hardware dongle plugged into the headunit handles the entire wireless negotiation independently, regardless of the phone's Android Auto version. - Native Mode (Wi-Fi Direct or Headunit Hotspot): communicates directly with Android Auto's native wireless protocol, without helper apps. - Headunit Server (essential for Self-Mode on AA 17.4+): starts the native Android Auto developer server directly on your phone or on the same device in Self-Mode. - Wireless Helper (for Android Auto up to v17.3): a companion app that triggers the wireless connection automatically in the background.

Wireless connection via Intent

- Trigger a wireless connection attempt with an Android Intent, useful for Taskon, MacroDroid, or ADB. - URI scheme: headunit://connect?ip=<PHONE_IP>

Known issues

- Google Maps in Portrait Mode: touch interactions may not work as expected on some devices. Reducing pixel density to below 200 (such as 190) often restores full functionality. - Wireless connection drops: disable WiFi Assistant or "Switch between networks" in your phone's Wi-Fi settings to prevent the system from killing the connection. - Self-mode on Android 10 and below: automatic wireless projection startup is disabled in Android Auto 16.4 and higher. Use the built-in Android Auto Headunit Server and connect via Wi-Fi mode (loopback) as a workaround. - Wi-Fi Direct takes long to connect: related to Google Assistant instead of Gemini for AA. Using Gemini on newer AA versions often runs smoothly. - Stuck on "Android is starting": check the video codec in settings and set it to H.264 if your device does not support H.265.

Requirements

- Android 4.1 or newer - USB Host mode support for wired connection - Android Auto installed on the phone

Disclaimer

Open Headunit is an independent, open-source project. Android, Google Play, Google Maps, Google Play Music, and Android Auto are trademarks of Google Inc. All trademarks belong to their respective owners.

License

GNU Affero General Public License v3.0