On Aug 7 2015 4:52 PM, Kenneth Lerman wrote: > I assume they use a De Bruijn sequence < > https://en.wikipedia.org/wiki/De_Bruijn_sequence> with perhaps a > manchester > encoding to guarantee frequent edges. > > All you have to do on startup is to see N bits. That will tell you > the > absolute position. Then interpolate some bit edges using a camera of > appropriate resolution. That would add additional bits. > > I have the parts for a laser interferometer sitting in my parts bin. > Maybe > it's time to fire it up and make some glass scales. > > What edge resolution can I get with a cheap camera/microscope?
I think that will strictly depend on the DPI resolution of the sensor/optics combination. There are a number of camera sensors which have 1000+ pixel resolution in a 0.75" sensor. That would likely put it on the 0.0005" range without much in the way of optics. Probably can do better, but this is likely a decent start. There used to be a place to upload files. I will post the files there. EBo -- ------------------------------------------------------------------------------ _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
