https://ru.aliexpress.com/item/Lusya-CSR8675-Bluetooth-5-0-APTX-HD-ES9038-XMOS-OTG/32910838023.html
ADK user guide
http://www.52bluetooth.com/csr/adk4.0/adkdocs/vm/application/CS-236868-UG.pdf
CSR8675 board button example
https://github.com/scottellis/csr8675_buttons
Ещё экзамплы
http://search.pudn.com/Download/index?content_type=download&keyword=CSR8675