On Saturday 18 March 2017 12:36:18 Abdul Rahman Riza wrote: > which Real Time kernel best for LinuxCNC... how about xenomai? > > On 02/23/2017 08:20 PM, andy pugh wrote: > > On 22 February 2017 at 19:35, Gene Heskett <[email protected]> wrote: > >> Not that I am aware of but its not magic, the basic jessie install > >> is the first step, then the rtai kernel is next > > > > ... > > This one is working well for me.
> >> Linux raspberrypi 4.4.4-rt9-v7+ #7 SMP PREEMPT RT Mon Mar 7 > >> 14:53:11 UTC 2016 armv7l GNU/Linux > > > > Just to clarify, that is not an RTAI kernel, that it a mainline > > PREEMPT-RT kernel. I don't believe that a truly rtai kernel has been built for the pi's yet. This one works fine as long as the interface card doesn't require a fast base-thread. Since the choice of interface cards has been made for us due to the lack of a parport, we are limited to cards that talk spi, which the pi can to a Mesa 7i90HD at 32 megabits/second if useing Mr. Martinjacks driver, rpspi.ko. You will have to make the interconnect cable as its 40 pin on the pi end, but only 26 on the card end, and the three driving signals from the pi's gpio's used need to be "source terminated" with 82 ohm resistors as close to the 40 pin connector as you can get them. The card however is a 3.3 volt fpga design and more than a bit fragile in the presence of all the switching mode noises from both the motor drivers and the psu's used, making a heavy, braided strap single point "star" grounding system mandatory, and a few clamp on ferrite chokes here and there are also helpful. That also means when wiring it up, that you are wearing one of those semi-conductive wrist straps with a grounding clip clamped on one of the braids from the grounding bolt to keep you from blowing the card with the static electricity you may be carrying. I bought a 3rd card after learning that lesson because I am backed up against the closed garage door when working on it, and it has an additional 2" of blue styrofoam glued to the inside so I can easily and cheaply heat or AC the garage, and my butt, rubbing against that styrofoam could put 5 kilovolts into me with one skid against the foam. > ---------------------------------------------------------------------- >-------- Check out the vibrant tech community on one of the world's > most engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
