It’s really just an ATTiny85 – a favorite of the crowd that’s just slightly above Arduino level – and an HM-10 Bluetooth 4.0 Low Energy module. This board was developed as a means to ...

A FT-232 USB to serial board is used to program the Arduino. A standard Bluetooth module has to have HID firmware installed. [Dastardly] makes a homemade daughterboard–er, shield–to connect ...