Quadrature encoders. Just wrote some PIC code to read one. The one we used in this project has detent so it "clicks" from position to position. When in one of its stable positions, both sets of contacts are open, so you can connect multiple encoders in parallel and adjust any one of them and have the PIC read it fine. I managed to do it with polling instead of interrupts. On detecting that the first contact had closed (to ground), I go into a count limited loop waiting for the second contact to close. Once both contacts are closed, I wait for the first contact to open, and immediately check the second. If the second contact is open when the first contact opens, the encoder is being turned one way. If the second contact is closed when the first contact opens, the encoder is being turned the other way. Works great! Harold On Wed, 26 Jun 2002 12:34:58 -0400 Erik Jacobs writes: > Lately in a lot of things, especially car stereo, I'm seeing more and > more > apparently "digital" knobs (some with pushbutton). Now, I'm > wondering what > they might be called, or where I could find something like them. > They make > great volume controls which can also double as selectors because, > unlike > pots, they don't "bottom out" or have a range of motion... but I > don't think > I'm telling anyone anything new. > > -- > http://www.piclist.com hint: PICList Posts must start with ONE > topic: > [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: > ->Ads > > FCC Rules Online at http://hallikainen.com/FccRules Lighting control for theatre and television at http://www.dovesystems.com Reach broadcasters, engineers, manufacturers, compliance labs, and attorneys. Advertise at http://www.hallikainen.com/FccRules/ . ________________________________________________________________ GET INTERNET ACCESS FROM JUNO! Juno offers FREE or PREMIUM Internet access for less! Join Juno today! For your FREE software, visit: http://dl.www.juno.com/get/web/. -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads