Rotation Counter

What you probably want is a rotary encoder (shaft encoder). These are readily available devices, or you can make your own out of slotted disks and photo-diode/transistor pairs. Either way, the support circuitry is rather simple.

These pages might get you started:

If all you need is a count of revolutions, then a single slot would be all you need. Another technique is to put a cam on the shaft and position a roller microswitch to register the revolutions.

Hope that helps, Daniel

Hi,

Have a look at the inards of an old mouse (the ones with a ball), I've used one for a simple rotation counter.

Regards Ian Dobson

Home of the Atmel based UDP mobile web cam

mails scanned with av-filter.pl (F-Prot / perl)

"kitmor" schrieb im Newsbeitrag news: snipped-for-privacy@z14g2000cwz.googlegroups.com...

Hi, I went the microswitch route since I had one hanging around. I just screwed a screw into the shaft then glued on a switch. So now I have a reliable rotation counter. Thanks for all the Ideas

--Kit

"kitmor"

Just keep in mind that with the microswitch you have no means to know which direction you're rotating, which could be fine for a myriad of applications.

Padu

using the encoders from an old ball mouse...or any sort of beam break sensor and a slotted wheel on the shaft