On Sat, 28 Aug 2010, Frank Tkalcevic wrote: > Date: Sat, 28 Aug 2010 07:46:52 +1000 > From: Frank Tkalcevic <fr...@franksworkshop.com.au> > Reply-To: "Enhanced Machine Controller (EMC)" > <emc-users@lists.sourceforge.net> > To: "'Enhanced Machine Controller (EMC)'" <emc-users@lists.sourceforge.net> > Subject: [Emc-users] Mechanical Encoders [Was new control panel] > >> The encoder is just unpowered mechanical switches giving quadrature. >> I had to add pull-up resistors (well I think I pulled up - I know I added >> resistors) to get it to work. If I remember right, the encoder gives 50 > cycles >> per rev instead of the more usual 100. It is not the greatest jog wheel > ever. > > Shifting topic slightly... > > How reliable/repeatable are the mechanical rotary encoders? A digital one > will give a nice clean A/B waveform, but will a mechanical one be > susceptible to debouncing? Or does the quadrature waveform take care of > this? (If it can be sampled fast enough) > > Frank >
Quadrature (2 bit Gray code) counting has no problems with noise at edges as it only causes a up/down one count dither until the noise goes away and no lasting count error. This is true as long as there is no noise on B when A is changing or noise on A when B is changing. (I have some ancient computer mice with mechanical encoders, basically metal wire brushes dragging on a built up silver/phenolic drum with alternate strips of silver and insulation) Peter Wallace ------------------------------------------------------------------------------ Sell apps to millions through the Intel(R) Atom(Tm) Developer Program Be part of this innovative community and reach millions of netbook users worldwide. Take advantage of special opportunities to increase revenue and speed time-to-market. Join now, and jumpstart your future. http://p.sf.net/sfu/intel-atom-d2d _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
