Disclaimer: Please note that this discussion is for advanced users who are comfortable entering commands through a terminal or console. We do not accept responsibility for any action leading to a bricked or non-functional head unit!
Installing ADB
First, you'll need the Android Debug Bridge (ADB) software on your PC or Mac. Here's an excellent post on how to get that installed on your particular machine:
How to Install ADB on Windows, macOS, and Linux
Setting up the head unit
Next, let's turn on the head unit and connect it to the same Wi-Fi network as your computer's. Then go to Settings > Wi-Fi, and tap on the upper right Options menu. Take note of the your IP address from the Advanced settings:
Next, let's give your computer permission to access the head unit. Go to Settings > Factory settings, and when prompted, enter the password "adbwf".
Connecting to the head unit
Now let's run the ADB client. Return to your computer, and open a terminal or console. If you have a Mac, simply open the Spotlight search and type "Terminal.app". If you're using Windows, open the Command Prompt program, and navigate to the ADB folder where you installed the software. Now that ADB is installed, we can connect to the IP address you wrote down earlier:
On the head unit, you'll be prompted to allow the connection. Tap on OK.
Entering commands
At this point, you can do all kinds of things to your head unit, but we're going to manipulate only one feature. You can issue any other command, but you do so at your own risk! Let's change the DPI setting. Try this:
You'll notice that the user interface is less legible with the smaller font, and the 120 value is definitely not something you'll want to keep, but you do get more screen real estate, and some apps will now function. For example, previous versions of the GoPro app worked well with our head units, but the latest version now has a welcome page with hidden buttons. Now you can move passed the page and log in!
After you've done that, you can try other DPI like 200 instead of 120. If you want, you can restore it to the previous DPI setting. At the moment, your computer is not connected to the head unit because of the reboot. Basically, you'll need to repeat the steps for connecting to the head unit, but you'll use a different value. For example, to go back to the original setting, use 240 instead of 120.
Everything should be back to normal with nice big icons for you to easily glance at as you're sitting in the driver seat. There are certainly more options available with ADB, and maybe we'll examine a few good ones in another post.