> What about contact (de-)bounce ? Fortunately contact bounce works itself out automatically in quadrature decoding. In theory, only one line at a time can bounce, so it looks like temporary jitter between two adjacent x4 quadrature states. That said, it is a good idea to apply a little analog filtering to remove the frequencies you know are higher that what the encoder can produce in your application. ***************************************************************** Embed Inc, embedded system specialists in Littleton Massachusetts (978) 742-9014, http://www.embedinc.com -- http://www.piclist.com hint: PICList Posts must start with ONE topic: [PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads