[Paid Software Announcement and Discussion] lovemyram4x4:
This awesome, I'm one of those that's needs this because my phone doesn't like to work with some of my Kenwood head units in my older cars. I'm on my second Essential phone, returned my first because I couldn't get AA to work and supports said they were working on a software fix but it may not work for all head units so it might be best to return the phone while I still can if I want AA. A few months ago I picked up another to see if it would work, straight out of the box no but after updating to Pie it worked. I didn't have time to set up the phone so I continued using my Pixel XL and when I finally got around to setting up my Essential it was already long past the return window but everything seemed to be working fine including AA. I had been mostly driving our 2019 Bolt and aside from some odd scaling (likely do to the aspect ratio on the phone) AA was fine. One day I hopped into my first gen Durango with a Kenwood head unit to take the dog to the vet and as tested AA worked fine, well so I thought on the way home it started doing the connect reconnect ever few seconds and ever since it would do that (even tried several older versions of AA).

I came across purely by accident. I was looking for a thread in the Essential phone section for Substratum and came across one about getting Essential phone on pie to work on wireless AA (I didn't even know it existed). So I Googled wireless AA was delighted to see that there was already after market head units with it but I really didn't want to have buy new ones but as luck would have it I also found this and now my Essential phone is working on my Kenwood head unit.

I have a lot of old phones I could use but decided one of my newer ones that should have better battery life would be best since I don't drive many of these cars every day or hardly ever when it comes to the Durango. So I started out with my Axon 7 and I'll probably use my Nexus 5 for my E39. Hopefully we'll get something for a zero wifi as I think I'll eventually have dead batteries in the phones (currently the Axon 7 looks like it will lose 3% per day how I have things set up-at least from full charge).

Slave set up.

Axon 7 with LOS 14.1-wipe phone and installed AAgateway and tasker

Setup tasker to switch between file transfer and charge only depending on connecting to master's hot spot. and to put phone into air plane mode and battery saver when not charging.

Master setup

Essential PH-1 currently stocked rooted Android Pie

Tasker setup to start hot spot and start headunit server when connected to Head units BT and stop hot spot on disconnect. I tried to use stopservice but as someone else posted I also could not get it to work, while force stop package worked it made so I couldn't get server to restart unless I open AA so I left that out, plus it's not really needed.

I haven't any issues yet but I only tested it after setting up and took 1 drive to the store. I'll see how it does on Sun when I take the Durango for a fill up (20 cents off fuel rewards). I probably only drive the Bolt until then but I may use the wireless setup instead of connecting.

If I find that the batteries in the phones become an issue (more likely for the durango) and a zero wifi doesn't become an option I had an idea for another approach using an Android stick. Since my Kenwood head units also have HDMI inputs I was thinking I'd run HUR on one and that way I wouldn't have to worry about any of the issues others are having and I could even keep it always powered so I wouldn't have to worry about boot times. I may just test this out with an Android box I have sitting around.