How to Use

How to Use

This guide covers starting the mirror once your phone is connected to the car — the two mirror entries and how they differ, and the start-up flow step by step.

Note

Before you start, make sure:

• ScreenOnAuto is installed and the three entries appear in Android Auto's launcher.
• You've opened the app once on the phone and granted the permissions it asks for.

The two mirror entries

Android Auto's app launcher shows two mirror entries. Both mirror the same phone screen — they differ in how the mirror is shown on the car screen:

	ScreenOnAuto	ScreenOnAuto (Legacy)
Display	Full-screen — takes over the map area	On a large enough car screen it can sit side-by-side with the map in split view; on a smaller screen the map simply goes to the background and only the mirror is shown (it does not replace the map)

ScreenOnAuto — full-screen, taking over the map area:

ScreenOnAuto (Legacy) — side-by-side with the map:

Try both and use whichever works better on your head unit. Both show the same mirror, and you can switch between them at any time — once mirroring is running, opening the other entry shows it right away without asking for permission again.

Start mirroring

With Auto Start Mirror ON (recommended)

1. In the app on the phone, turn on Auto Start Mirror (one-time setup).

2. Connect the phone to the car and tap a ScreenOnAuto entry ( or ) in the Android Auto launcher.

3. The phone brings up the screen-capture permission dialog automatically — pick up the phone and tap Start now:

   

4. Your phone screen appears on the head unit:

   

Note

The permission dialog is an Android requirement — it appears once each time mirroring starts, not on every screen change. With Auto Start Mirror off, tapping the entry only opens the mirror screen; nothing is captured until you start it yourself.

Starting manually

If you prefer to keep Auto Start Mirror off:

1. Open ScreenOnAuto on the phone and turn on the Mirror switch, then tap Start now in the permission dialog.
2. On the car screen, open one of the ScreenOnAuto entries — the mirror is already running and shows immediately.

(The order doesn't matter — you can also open the entry first and flip the Mirror switch after.)

Skipping the permission dialog

Tired of the dialog appearing every time? You can pre-grant the permission once via ADB — see Grant Mirror Permission via ADB.

Stop mirroring

Any of these works:

• Disconnect from the car — mirroring stops automatically (the default Stop on disconnect setting).
• Tap Stop Mirroring on the persistent phone notification.
• Turn off the Mirror switch in the app.

Troubleshooting

• Black bars around the image — the phone and car screens have different aspect ratios; turning on Force Landscape (in the app's settings) usually fills the screen much better.
• Entry opens but stays blank — mirroring hasn't started yet; check the phone for the permission dialog, or start it via the Mirror switch.
• The Android Auto navigation bar on the car screen is drawn by Android Auto itself and cannot be hidden by the app.