Counting an action: Either a revolution or movement?

[sjaguar13]

I need to count each time an action happens. For each action, there are two ways I can think to count it. First, a plastic cylinder spins around. I could increment the counter when the the top of the cylinder is pointed at the bottom, 180 degrees spun around. The second option would be to have some kind of infrared laser that increments the counter if the laser is broken.

I have no idea how to do either. I need it so they are all logged into some kind of device (probably a computer) so that I can monitor all counters. Any ideas on how to get this working?

 

[MikeMl]

Look up the following sensors: Opto-interrupter, Photo-transistor, Photo-diode, Hall Effect, magnetic reed switch. Pick one.

You can buy ready-made totalizing counters which display the counts in LED or LCD displays.

If you have software capabilities, you can use the sensor to pulse a pin on a computer parallel or serial port, and write the totalizing and display software yourself. Without a lot of work, a parallel port could simultaneously count about a dozen inputs.

 

[sjaguar13]

I saw the LCD display counters, but I didn't know how to get that result online. I have been looking at infrared interruption counters, like this one:
Infrared Interruption counter (AT89C2051)

The biggest problem I have is getting the results online. I am guessing I need to hook it up to a computer that sends a request to a website that stores the response and displays it. Space will be limited, so I need to find a computer small enough to fit. 14 would be the most counters I need to keep track of on a single computer. Think that's possible?

Could something like the XBee handle this, or does it require a computer?