hi,
Dont wish to sound 'picky' but this simple wire pendulum is a far cry from the pendulum descriptions posted in earlier posts
If you decide exactly the range/shape etc of the pendulums and any restrictions regarding attachments to the pendulum I am sure a simple solution to measuring and displaying the period could be suggested.
It could easily done via the PC's parallel or serial port.
Its the permitted detection method and access that needs to be decided.