On Mon, 14 Apr 2014, John Kasunich wrote: > Date: Mon, 14 Apr 2014 11:56:06 -0400 > From: John Kasunich <jmkasun...@fastmail.fm> > Reply-To: EMC developers <emc-developers@lists.sourceforge.net> > To: emc-developers@lists.sourceforge.net > Subject: Re: [Emc-developers] Unit conversions in Canon > > > > On Mon, Apr 14, 2014, at 11:10 AM, Kirk Wallace wrote: >> >> I think there is a different distance scale per axis problem no matter >> what units one choses. My guess is that there may be a way to use >> encoder counts to run the motion back end such that only integer math is >> needed. If each axis had a machine unit to encoder count factor, then a >> user unit to machine unit conversion could be pushed out to the user >> space. The machine scale could be set to, let's say 1000 ticks per >> smallest distance to encoder count, then calculations could be done >> without decimal points and still have enough resolution. >> > > If this was 1980, it might be important to try to do the motion control > math in encoder counts (or stepper steps) so it could be in integer > and run faster. > > If we were porting LinuxCNC to an AVR or Arduino it might be > important today. > > For PCs, floating point math is pretty much as fast as integer math. > (Some operations are faster actually.) I think the same applies to > ARMs like BeagleBone.
Even for Arduino scale/priced stuff FP hardware is becoming available we are changing some of our DSPIC stuff over to STM32F303's (72 MHz ARM+FPU uproc) ~$3.25 in 100's complete with 4x 5 MS/S 12 bit A-Ds > > -- > John Kasunich > jmkasun...@fastmail.fm > > ------------------------------------------------------------------------------ > Learn Graph Databases - Download FREE O'Reilly Book > "Graph Databases" is the definitive new guide to graph databases and their > applications. Written by three acclaimed leaders in the field, > this first edition is now available. Download your free book today! > http://p.sf.net/sfu/NeoTech > _______________________________________________ > Emc-developers mailing list > Emc-developers@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-developers > Peter Wallace Mesa Electronics (\__/) (='.'=) This is Bunny. Copy and paste bunny into your (")_(") signature to help him gain world domination. ------------------------------------------------------------------------------ Learn Graph Databases - Download FREE O'Reilly Book "Graph Databases" is the definitive new guide to graph databases and their applications. Written by three acclaimed leaders in the field, this first edition is now available. Download your free book today! http://p.sf.net/sfu/NeoTech _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
