The HP ExpressCard X54 Mouse (GK872AA) is a Bluetooth mouse that sits flush into a laptop ExpressCard slot when not in use. It defaults to mouse-only mode. Pressing the "Mode/Bluetooth" button on the underside for 1 second toggles between laser-pointer mode, and mouse mode. The LED at the top gives the show the mode: green for charging, red for presenter/laser mode, and blue for mouse mode. See the PDF instruction manual.
Physically there are three hardware buttons on the top: left, middle and right. Below this is a micro-trackpad area. The following events are sent:
|Mouse mode||Laser mode|
|Bottom||(1 second press) to Laser mode||(1 second press) to Mouse mode|
|Left||Pointer Button 1||keyboard Previous|
|Middle||Pointer Button 2||(press and hold) Laser|
|Right||Pointer Button 3||keyboard Next|
|Touchpad||(stroke up) Wheel/Pointer Button 4||(double-tap, alternating with Escape) keyboard shift-F5|
|Touchpad||(stroke down) Wheel/Pointer Button 5||(double-tap, alternating with F5) keyboard Escape|
|Touchpad||keyboard Back||(double-tap, in F5 state) keyboard b|
|Bottom||(5 second hold) Bluetooth pair||(5 second hold) Bluetooth pair|
If the device is off, double-click the Left of Right button and wait ~5 seconds for it to start up. There is no "off" button, it appears to simply time-out (which helps with battery saving!). Double-tap and wait to wake it up again.
All functions work out of the box in Ubuntu 12.04 LTS and the Evince PDF viewer. Use "System Settings" and "Bluetooth" to pair the device.