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.
I agree it is a lot different. When I first started I was assuming that I could measure the time of the pendulum by passing the object swinging through or by some device to trigger my timer. But there is also another way, I could attach a thin object to the pivot point and let that object break the light path also. Either one will work equally well. My period will be about 1 second and all I need to do is use the photogate to start and stop a timer. It would be great if the timer had a sensativity of 1 ms but 1/100 sec is fine.
If I were to use the one that I have in the picture above I would use an adapter on the pivot pin and use the photogate to detect with the adapter passed by. If I had a way to measure the pendulum directly the gate would have to have an opening of about 12". If I used UV paint all I need to do is place the LED close to the pendulum. Any method would work.