Broken triggers limit an optimum gaming experience with the Nintendo Switch console. RetroArch and libretro provide a way to take an existing emulator and load that emulator as a library or 'core'.
It seems like either one controller or the other works but not both. XIM4 requires your console's Controller to work: XIM4 needs your console controller plugged into it at. The Assign LED on the left will flash white once. Select a control to edit (fader, pad, button, etc. Tip: To turn AssistiveTouch on or off quickly, triple-click the Home button (on an iPad with a Home button) or triple-click the top button (on other iPad models).
I should probably update the other PS4 and try the FPS Pro on it.
