Enable multi-display support for Raspberry Pi 4B (RPi4)

In this article, we will guide you on how to enable multi-display support on Android 14 for Raspberry Pi 4.

Steps to enable multi-display support:

1. Activate Developer options
2. Enable multi-display support
3. Reboot device

Multi-Display Mode in Android works differently compared to our regular computer. Android is not designed for several external monitors, so each input device is mapped to a specific monitor without the ability to switch to a different monitor.

To be able to control two displays, we added a USB Port to HDMI port HID/Touch event routing. This means:

• USB Port 3 is routed to HDMI Port 0, and
• USB Port 4 is routed to HDMI Port 1.

Step 1 - How to activate Developer options

To access Developer options on your Android 14 device, follow these steps:

1. Access the App Drawer on your device by simply swiping up from the bottom of the home screen.
2. Open Settings.
   
3. Scroll down and select About tablet.
   
4. Search for Build number and tap it repeatedly until you see a message confirming that you are now a developer.
   
   

Once you have enabled Developer options, you can proceed with enabling multi-display support.

Step 2 - How to enable multi-display support

1. Go into Settings and choose System.
   
2. Scroll down and find Developer options.
   
3. Continue scrolling down until you locate Force desktop mode and toggle it on to activate multi-display support.
   
4. Enable freeform windows (optional) to open apps in separate windows instead of full-screen mode. This feature is similar to how it works on a PC, giving the flexibility to move the windows around and resize them to a preferred size.