I recently purchased a Bluetooth 4.0 adaptor for my laptop. Bluetooth 2.1 was recognised instantly, but Bluetooth 4.0 is not recognised. Is there a fix for this, or is Ubuntu not compatible with Bluetooth 4.0?
Ubuntu uses the Bluez protocol stack for Bluetooth. From supported protocols we can see what is supported at present:
Core specification 4.0. Not (yet) 3.0+HS. Includes GAP, L2CAP, RFCOMM and SDP from BlueZ
So the answer is yes, we do support Bluetooth 4.0. You may want to search for specific bugs or incompatibilites with existing brand-new hardware, or have a look at the BlueZ development branches at GIT for more details on future plans, and to find out if your device or a protocol your device needs has issues.