-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 2/1/2013 2:51 PM, Gregory Perry wrote: >> ________________________________________ From: Charles >> Steinkuehler [char...@steinkuehler.net] Sent: Friday, February >> 01, 2013 3:40 PM To: EMC developers Cc: Gregory Perry Subject: >> Re: [Emc-developers] Python Library for the BeagleBone PRUSS >> >> -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 >> >> On 2/1/2013 2:16 PM, Gregory Perry wrote: >>> Forget using Xenomai or RT_PREEMPT on the BeagleBone, check >>> this out: >>> >>> http://hipstercircuits.com/?p=349#comment-269 >> >> Yep...we're already using the PRU to do stepgen: >> http://git.mah.priv.at/gitweb/emc2-dev.git/blob/refs/heads/arm335x-hal-pru-module:/configs/pru-examples/stepgen.p >> >> >> But you still have to run Xenomai or PREEMPT_RT on the ARM or you get >> things like 100 mS latency 'hiccups', which is unworkable for >> LinuxCNC. <snip> > > Why not just have Python do the translation and feed the gcode to > the PRU? The RISC cores on the PRU are completely autonomous from > the Angstrom Linux kernel, so where would the 100ms hiccup come > into play there? The process feeding gcode to the steppers?
The 100 mS 'hiccup' comes into play for anything running on Linux (which is running on the ARM core) if you don't have help from something like Xenomai or PREEMPT_RT. You absolutely could use Python to feed gcode to the PRU, but then you need to implement most everything that is LinuxCNC (the motion logic, HAL, etc) on the PRU. Or you could implement something simpler, like the Marlin/Sprinter/Teacup/Grbl/etc., but written for the PRU. At this point, however, what you have is *NOT* LinuxCNC. - -- Charles Steinkuehler char...@steinkuehler.net -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (MingW32) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iEYEARECAAYFAlEMLYMACgkQLywbqEHdNFzDogCfeNYGzZTflRQhAEhMHnyfeEVP sloAoK66W7pIeOhYt5z/E6VB4U7QCc5I =XBKG -----END PGP SIGNATURE----- ------------------------------------------------------------------------------ Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: http://p.sf.net/sfu/appdyn_d2d_jan _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
