3-LED Backlight: Xamarin and Arduino With HC05
https://www.instructables.com/id/3-LED-Backlight-Xamarin-and-Arduino-With-HC05/
Xamarin.Forms to Arduino over Blutooth Classic
https://forums.xamarin.com/discussion/90704/xamarin-forms-to-arduino-over-blutooth-classic
https://habr.com/ru/post/463691/
Bluetooth Arduino + Xamarin.Android
http://alejandroruizvarela.blogspot.com/2014/01/bluetooth-arduino-xamarinandroid.html