Thank you for the response!Wireless Android Auto works for some devices without WiFi Launcher (native wireless android auto). But problem is for those devices, that doesn't support wireless AA natively, that's why WiFi Launcher was developed.
So this is how WiFi Launcher works (with my limited knowledge):
From now on, only WiFi is used I think. BT is too slow (really low bandwith) for anything more than audio, so it can't be used for Android Auto. It is only used, for phone to know, when it needs to start connecting to WiFi and starts wireless Android Auto.
- You turn on the car and HUR is launched on headunit.
- HUR starts listening for incoming connection.
- Your phone automatically connects to your headunit using BT. (BT is used here only for WiFi Launcher to know, when your phone connects to your headunit, so it can know when to connect to HUR)
- WiFi Launcher gets notified, that your phone has been connected to headunit via BT, so it starts connecting to headunit WiFi.
- After phone is connected to hedaunit WiFi it starts connecting to IP of headunit and port where android auto "server" is running on headunit.
WiFI Launcher is also open source, so you can check code if you really want.
Why does it need a location access? Because Google is sometimes really dumb, and they made location access required when you need to search for BT/WiFi devices (I am not sure if only BT devices, only WiFi devices or both).
Actually I'm fine with the mandatory "location on" requirement, not cause google wants location access when searching for wifi, but cause I'm using Waze do need location on anyway.
Regarding the wifi connection, my phone model is OnePlus 9 pro, pretty advanced, so it shouldn't use the wifi channel for Android auto, and anyway my phone works great with only BT on my wife's car android auto (native in that headunit).
So what do I need to change in order to work only with BT?
The reason I'm asking is cause I want the headunit to connect to the phone's hotspot for internet access in case I don't want to use AA