Using an Upek fingerprint reader for 2D scrolling and middle mouse button.

The latest version of the code can be found at: 
https://github.com/RoaldFre/upekMouse

You need the Upek SDK for this to work from:
http://www.upek.com/solutions/pc_and_networking/sdks/linux/

[********************************* UPDATE *********************************]
The above link no longer seems to work. Apparently Upek merged into 
AuthenTec in October 2012, followed by them dropping all support (as 
mentioned on http://support.authentec.com/Home.aspx at the time of 
writing).

There is still a page on their new site that mentions the SDK: 
http://support.authentec.com/Downloads/Drivers/Linux.aspx
Alas, the link in there is also broken at the moment.

Search keywords to find the SDK elsewhere would be something along the 
lines of "BSAPI SDK". Please let me know if the situation has changed, or 
if you've found a mirror somewhere. My email adress is at the bottom of 
this document.

For the time being, I've found a mirror at
https://bitbucket.org/hughw/biopass/src/f65714410179cad31d2a02ca26fe3fd31b29bdaa/BSAPI_3.6_for_Linux
I'm not too keen on bundling it myself because of licensing issues.
[******************************** /UPDATE *********************************]

The scolling has a feature of inertia to allow one to efficiently scroll 
large distances. The parameters can be adjusted in the source file.

A small word of caution: The binary blob from Upek fires a timer about 1000 
times per second. These wakeups give an additional 2 Watts of power usage 
on my laptop, I therefore disable this when running on battery power.
More caution: There appears to be a bug in the code that makes it crash if 
you compile with high optimizations. If you find it, please let me know.

The licence on the code:
Do whatever you want with it, but drop me a word if you use it or did 
something awesome with it ;-).


Roald Frederickx
roald <dot> frederickx <at> gmail <dot> com