I was thinking more about something like the STM32 discovery boards. The STM32 micro controller have an Cortex-* CPU with nested interrupt controller. The Raspi is essentially an ordinary computer and I have not been able to figure out if it have nested interrupts and the idea was to get rid of everything that may delay CPU every now and then. I run control loop at 40kHz which is equal to a period of 25µs on STM32 and it works perfect including low priority taks not because of performance but because nothing will stop it from getting the necessary clock cycles then needed.
GUI --> G-code, motion planner and other real time --> Motor controlling switches. GUI would be on ordinary computer which usual work well but may delay CPU every now and then. G-code, motion planner and other real time would be on micro controller which may not delay CPU every now and then. Motor controlling switches would be on separate card, usually there is need for electrical isolation anyway especially if running from voltage which may be dangerous. The point is to get rid of the annoying delay for unknown reason every now and then. What is good enough for video with maybe 50 frame per second is not good enough for tasks running twenty times as often even if CPU is very fast but small unknown delays may happen. Nicklas Karlsson On Wed, 3 Feb 2016 12:23:11 +0100 "W. Martinjak" <[email protected]> wrote: > OK, not as easy... > I will reword my question. > > I've made a driver based on the pluto board and it's working on machinekit > with > raspi2 over spi and other altera boards. > Partly works with beagleboneblack. > https://github.com/tinkercnc/spi-fpga-driver > > And I asked if it would work with Lcnc. > > > > On 2016-02-03 03:24, Jon Elson wrote: > > On 02/02/2016 06:24 PM, W. Martinjak wrote: > >> How far is the development of lcnc on raspi/arm? > > LinuxCNC has been running on the Beagle Bone Black for > > several years. It is mostly the same codebase as LinuxCNC, > > except for running on the Prempt-RT kernel (I think I got > > that right). > > The Beagle Bone Black has a pair of 200 MHz microcontrollers > > that are used to handle step generation and other low-level > > I/O tasks at much faster speeds than the Linux CPU can deal > > with them. Great for software step generation. The Pi does > > not have these microcontrollers. > >> Would this [1] work with bare lcnc installation. > >> > >> > > No, the regular LinuxCNC distribution is for an X86 > > platform, only. Machinekit is the distro for the Beagle. > > I think people have gotten it running on the Raspberry, but > > the I/O on that board is VERY limited. > > > > Jon > > > > ------------------------------------------------------------------------------ > > Site24x7 APM Insight: Get Deep Visibility into Application Performance > > APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month > > Monitor end-to-end web transactions and take corrective actions now > > Troubleshoot faster and improve end-user experience. Signup Now! > > http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 > > _______________________________________________ > > Emc-developers mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/emc-developers > > -- > "In der Wissenschaft siegt nie eine neue Theorie, > nur ihre Gegner sterben nach und nach" > > Max Planck > > > ------------------------------------------------------------------------------ > Site24x7 APM Insight: Get Deep Visibility into Application Performance > APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month > Monitor end-to-end web transactions and take corrective actions now > Troubleshoot faster and improve end-user experience. Signup Now! > http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 > _______________________________________________ > Emc-developers mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-developers ------------------------------------------------------------------------------ Site24x7 APM Insight: Get Deep Visibility into Application Performance APM + Mobile APM + RUM: Monitor 3 App instances at just $35/Month Monitor end-to-end web transactions and take corrective actions now Troubleshoot faster and improve end-user experience. Signup Now! http://pubads.g.doubleclick.net/gampad/clk?id=267308311&iu=/4140 _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
