  An optical mouse that is in common use with personal computers is employed to
measure the motion of a pendulum. The pendulum can be monitored (i) realtime
only, or (ii) also with data storage for later detailed analysis using Excel.
The software developed for this purpose is a LabView executable algorithm. It
allows the user to select among several modes that include filtering
operations. The limiting resolution of this position sensor, which is in the
neighborhood of 50 micrometers, is determined by the 'dpi' specification of the
mouse.
