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Discussion Starter · #1 · (Edited)
Showing this as a concept for possible displaying useful Car/Drive data information on your Android Auto Screen

The idea is to overlay text data on the Android Auto video stream - yup its video data passing through the USB cable generated by the Android Auto app on the phone and decoded on the headunit side for playout on your infotainment sceen. On the headunit side, a library called gstreamer was used to decode the stream and display it on the screen.

Gstreamer has an optional plugin called Pango TextOverlay or the CairoTextOverlay which is readily available as an opensource. You can attach this to the existing headunit codes as a layer on the AA video stream pipeline.

Here is the tricky part. The gstreamer currently attached on the infotainment does not contain these textoverlay plugins. You will have to rebuild the libraries and plugins from scratch. One possible option is to use Yocto or LTIB. LTIB was used for this to generate the necessary toolchain libraries. You also need to install the fontconfig libraries for the Pango plugin to work :) Fontconfig was also built via LTIB

Attached image is an example of such execution wherein Tire Pressure and Temperature data was displayed as an overlay on top of the AA video. The infotainment buttons was used to toggle the overlay to ON or OFF :)

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Discussion Starter · #2 ·
Using the latest version of Android Auto V3.2 and aside from TPMS data gathered from a bluetooth receiver and four bluetooth based tire sensors, Battery State of charge is also displayed as a video overlay.
 

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