[Android Automotive OS] Tachi91:
Just so that it's available here. Below is the image of the Dongle Daisy chain result that the reddit poster accomplished.

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Thats Full-Screen CarPlay via the Android MStick3 - AutoKit CCPA. Unlike the example of my setup from above. Where there is a permanent sidebar present forcing the projection to almost half the size. With CarPlay scaling appropriately for both. As seen by the extra icon column. This is also different from how the Built-In Google Maps handles the sidebar. Instead of simply being collapsed to the side with a toggle visible either show the sidebar or keep it hidden/collapsed. The one from reddit is gone with the Android MStick3 mimicking Android Auto and being drawn overtop.

I did purchase the same dongles they had, but I'm still waiting for it to arrive. However, In the meantime I've kept messing around with a Raspberry Pi 4B running lineage OS. Trying to first get Android Auto from it to Project onto the Vehicle. The first few attempts using LineageOS 21 failed with AA communication Error 11. I was partially successful using LineageOS 20, but it projects a black screen.

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The Pi/LOS20. I tried the AA Developer Option and tested it with Wireless AA disabled and wired only as well as over Wireless only. Same result, I was sleep deprived and forgot to get ADB going on the Pi. Maybe something is being called out in the log for a missing file or permission error. I don't have an Android Phone so this is my only avenue to see how Android Auto interacts with GMs AAOS. There is a fade animation when switching to the Android Auto Projection where the sidebar does disappear.

Looking thought AAOS settings > Permission. What is presented to the user doesn't allude to much. There is a difference in the summary for Both AA and CP. However when you go into "All Permissions" it does list more things, but most are about other seemingly unrelated car features.

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I did not remove the HMI, yet, but did get my eyes on it. I was also able to search online using some of the info on the sticker that I could see.

From what I saw this is similar if not the same. [Source]

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The branding on it, besides GM, is Harman (Samsung subsidiary) with [INFO3.7-3.8 CSM] as the model number. Now, if you search that you'll get several interesting hits besides that AJR picture. Specifically a website article titled "Deep Dive Teardown". Whatever this write might, be is behind a freemium wall. I signed up for the free account and sent a request to be allowed to "subscribe". I would hope it's 1. Not ridiculously expensive for file access and 2. An Actual technical breakdown, photos, etc etc etc. Of the board itself and maybe software.

This other site has a few PDFs with pictures of the actual HMI. One issue with some of those pictures is the Part Number on the sticker. It is not the same as the one I have [86509619]. Whether that's from a a very specific feature set or if it's just a similar, but not the same model. However the 3.7-3.8 would match. I can't image GM forking out R&D for several hardware variations instead of cheaper software locks based of VIN.

Until either I, the internet, or magic gets Internal pictures. I'll attach pictures from the HARMAN certification paperwork. As a similar enough reference at lease.

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