Android Auto Desktop Head Unit (DHU) shows black screen on launch

I’m trying to connect to the Desktop Head Unit (DHU) for Android Auto testing and keep getting a black screen when I launch it. I can see the red & green touch artefacts when I click & right-click on it.

I have followed all the instructions here: https://developer.android.com/training/cars/testing.

I get no console errors and I have ensured the Android Auto app has developer mode enabled & the head unit server is running. I have also tried different tcp ports.

I am using a Mac with stock Android 10 on a Pixel 3 for the phone part of the connection, latest updates to everything. I have also tried another physical device with Marshmallow 6.0.1. Android Auto app on the phone is version 5.5.602944-release.

This is the first time I am using the DHU and I have tried clearing the cache & resetting everything on the Android Auto App on the phone.

I did notice when I have the Android Auto app open and I launch the DHU from the terminal the Android Auto app on the phone closes (which I don't think should happen - but I may be wrong there).

Solution

I also had this issue, everything seemed to be working fine, but the DHU remained black every time. I've been using a pixel 4 with android 10, and mac os.

Start by resetting the android auto app
revoke all permissions
close the DHU
when following the instructions, never tap the android auto app icon.
go through the settings -> applications -> android auto -> extend advance -> additions settings in the app -> and here enable dev settings.
start the server
start the dhu
if the black screen is visible, then stop the server, exit DHU
start the server again, and open DHU.

--- at this point the application should launch showing you the initial screen and asking also permissions for the different things.

allow all and continue the usual initial setup. The DHU now should show the AA home.

These steps worked for me.