Player constantly spinning when pressing Caps Lock
First, check your ease of access settings in control panel, and make sure it matches this picture.
Look at the image link I posted and make sure yours matches it's settings.
Control Panel >> Easy of Access Center >> Make the Keyboard easier to use`
Uncheck everything.
One more thing you can try.
Go to your Documents Folder > Battlefield 4 > Settings and rename the file called PROFSAVE_profile to PROFSAVE_profile.old
Restart your PC and start the game back up. It might be necessary to run the Repair Game option in Origin, but I doubt it.