NBL1064-dat
Info
product url - Bluetooth IO Control Board EDR 2.0, BLK_IO
Board Map, Dimension, Pins, chip info, Use Guide, Setup Jumper, etc.

on board chip STM8-dat
main bluetooth chip: BC417143B1 - BC04-dat - https://w.electrodragon.com/w/Category:BC-04 - NBL1022-dat
SCH

Applications, category, tags, etc.
Demo Code and Video
ref
legacy wiki page
https://www.electrodragon.com/w/Category:Bluetooth_2.0#AT_Commands