Pressing the button on the bluetooth device does nothing.
I can see the bluetooth device paired with name “gamepad” inside the retropie configuration script.
In shell I can see the j0 in /dev/input/.
My tips and questions:
Install the package ‘joystick’ w/ the Linux command on the command line:
sudo apt-get install joystick
Now test your joystick(s) w/:
And press some buttons on the controller. You should see some reaction. Remember: if you’ve got more than one controller the bluetooth controller may be js1 or js2.
If ‘jstest’ proves that the output of the BT controller is actually received by the Pi then register the controller in Emulationstation w/ the procedure I described above. Realize that a BT connection my be quirky. Sometimes a BT connection stops and starts in my experience.