I recently installed rasplex on a rpi 3, and turned bluetooth on and synced my Nexus Player Remote. Up/Down/Left/Right/Play/Pause work, but Back/Home are not working as you would expect and the center button isn’t working at all.
So I figure they just aren’t mapped. I turned on debugging and connected via SSH and ran tail -f /storage/.plexht/temp/plexhometheater.log so I can take a look at what the buttons are sending to remap them.
The problem is, the Center button is throwing up this:
DEBUG: CLinuxInputDevice::KeyEvent: TranslateKey returned XBMCK_UNKNOWN from code(353)
for reference, if anyone is wondering, the buttons that the remote throw are:
Voice Search - DEBUG: CLinuxInputDevice::KeyEvent: TranslateKey returned XBMCK_UNKNOWN from code(217)
Up - up
Down - down
Left - left
Right - right
Center - DEBUG: CLinuxInputDevice::KeyEvent: TranslateKey returned XBMCK_UNKNOWN from code(353)
Back - backspace
Play/Pause - play_pause
Home - home
EDIT: Some googling makes it sound like there is no way to fix this without adding the missing buttons to the source code (xbmc/input/linux/LinuxInputDevices.cpp) and recompile 
I hope there is another solution besides this. AFAIK, you can install Kodi on the nexus player and the remote works fine, same with plex, but clearly this isn’t comparable to that.
