Set Up Your AI Box at Home With Android's Desktop Head Unit

Why set the box up on your desk?

An AI box only starts its interface when a car’s head unit asks for it, so most owners do their first setup in a cold car with a laptop on their knees. Google’s Desktop Head Unit (DHU) is the emulator Android developers use to test Android Auto apps. It plays the part of the car on your PC, and the box cannot tell the difference.

On a desk you can sign in to accounts, install and arrange apps, try a launcher, install a firmware update and check sound, all with a mouse and keyboard. One owner set up a new TBox Ultra completely this way, updated it, and only then fitted it to the car.

How the connection works

DHU in USB mode waits for an Android device that speaks the Android Open Accessory (AOA) protocol. When you plug in a box that is in Android Auto mode, it first appears to Windows as an ADB-interface device; DHU asks it to switch, and it reappears as an AOA device. From then on the box streams its screen and sound to the DHU window and receives your clicks as touches.

Two practical consequences follow. Windows needs a working driver for both stages, and DHU must already be waiting when the box is plugged in, because the box only looks for a head unit once at start-up. That is why owners run DHU in a loop that restarts it every time it exits.

Before you start

Android Studio is a large download. Unofficial bundles with DHU and drivers inside also circulate, but they cannot be checked, so install DHU through Google’s SDK Manager as described below. You need Android Studio only for its SDK Manager; you will not write any code.

Plan the session on a desk near a wall socket. The box draws more current while it boots and installs apps than a laptop port may supply, so keep its extra power lead and a USB charger at hand. Use the data cable that came with the box; charge-only cables are a common reason a computer sees nothing at all.

Finally, note how your box is switched between CarPlay and Android Auto, because you will switch it twice: to Android Auto for DHU, and back if your car uses CarPlay.

Steps

cd "$env:LOCALAPPDATA\Android\Sdk\extras\google\auto"
dir

adb kill-server

while ($true) {
    .\desktop-head-unit.exe --usb -c .\config\default_720p.ini
    Start-Sleep -Milliseconds 25
}

What to set up while the box is on your desk

Work through this list in one session; it covers what owners most often did at home before fitting the box:

1. Accounts. Sign in to Google Play and to your music and navigation apps. Typing passwords with a real keyboard is the main reason owners use DHU.
2. Apps and launcher. Install your apps, set the default home app and arrange widgets. If you plan a third-party launcher, read set the stock launcher before any firmware update first.
3. Firmware. Install pending updates with the FOTA local update while the box has stable power from the desk.
4. Engineering menu. Open Settings → Other → Factory settings → 4545 and photograph every page, so you can restore the settings later. Start-up delay and the navigation bar are the ones that decide how the box behaves in the car; the engineering codes reference lists what each code opens.
5. Network. Insert the SIM and confirm mobile data works, or join your phone’s hotspot. Owners who saw the network exclamation mark cleared it at the desk with the exclamation mark fix.

What DHU cannot test

DHU is a stand-in for the screen, not for the whole car, so some things only show up on the road:

• Car GPS and sensors. DHU sends no vehicle data, so the box uses its own GPS indoors, usually with no fix. Check navigation in the car.
• Steering-wheel buttons and the car’s microphone. Button mapping and call audio depend on the head unit.
• CarPlay mode. DHU only speaks Android Auto, so CarPlay-specific behaviour cannot be checked.
• Power under load. A desk charger is steadier than a car’s USB port; reboots that appear only in the car are a power question, not a setup one.
• Screen fit. The DHU window uses the resolution in its config file; the car’s panel may be wider, taller or portrait.

Verify it worked

You know it works when the DHU window shows the box’s launcher and responds to clicks. Then check three things before relying on the setup:

1. Open Settings → About on the box and note the firmware date.
2. Play music: sound from the box comes out of the PC’s speakers. One owner caught audio crackle during his DHU session and cleared it by lowering the volume and rebooting; if crackle persists, see crackling or muffled sound.
3. Unplug and plug in again with DHU waiting. The box should reconnect without a reboot loop.

Undo / rollback

DHU is read-only from the box’s point of view; it acts as a screen and does not install anything on the box. Everything you change while connected (apps, settings, firmware updates) is a normal change on the box, undone the normal way.

The one setting to put back is the protocol. If your car uses CarPlay, switch back from Android Auto before you go to the car, or the head unit will not see the box.

Troubleshooting this guide

DHU prints “No device found ready yet” over and over. Windows has no driver for one of the two USB stages. Install the Google USB Driver for the ADB-interface stage and an AOA driver for PID_2D00, as in the driver step, and run adb kill-server again.

The DHU window stays black and nothing is detected. One owner had this on a heavily stripped-down Windows build. After installing a standard Windows 11 the setup worked at once. Try another PC before reinstalling anything.

DHU closes after a few seconds. Without the loop, DHU exits when it finds no device. Run it in the loop and plug the box in after the loop is running.

The box keeps restarting while connected to the PC. Some PC ports cannot power the box under load. Connect the box’s extra power lead to a USB charger, or use a powered port; AI box keeps rebooting explains the power side.

“Video focus is off” on a black screen after clicking a DHU menu item. An Ultra 2 owner hit this after clicking the CAR menu by accident; it then appeared at every connection. Nobody reported a fix, so leave DHU’s menus alone during setup.

You want DHU over ADB instead of USB. Google’s page also describes an ADB tunnel mode, which needs the Android Auto app on the device with its developer head-unit server. Nobody reported using it with an AI box; the USB mode above is the one with reports. If you do need ADB for other jobs, see enable ADB on an AI box.

The box is in Android Auto mode but the car only does CarPlay. That is expected after a DHU session. Switch it back before going to the car.