Author here.

I wrote a retrospective that might be interesting to read to some: https://github.com/darthcloud/BlueRetro/discussions/289

In this article, I detail how my initial goal of leaning more about Bluetooth and sell a product turned into a software platform makers now use to sell their own hardware take base on my original design.

You can easily give the project a try without building a full adapter. If you got a dev board with the original ESP32 you can flash [1] the BlueRetro_pad_test.bin firmware, connect a Bluetooth device [2] to it and see the buttons inputs from a terminal [3]. You can also connect to the web Bluetooth interface [4] to take a look at the configuration.

To simply see the adapter in action you can look at my original Hackday Prize submission video [5].

[1] https://github.com/darthcloud/BlueRetro/wiki/Flashing-firmwa...

[2] https://github.com/darthcloud/BlueRetro/wiki/Controller-pair...

[3] https://github.com/darthcloud/BlueRetro/wiki/Getting-BlueRet...

[4] https://blueretro.io/

[5] https://www.youtube.com/watch?v=yj_Zbjb2_ms

Very impressive project, and huge props for having everything open source. The hackaday articles on the controller communication protocols are especially interesting to me, high quality documentation like that is so hard to find.