I don't want to start up a Machinekit vs LinuxCNC argument but the developer of Remora has been using LinuxCNC with the 2.8-rtpreempt kernel which seem way out of date. I know this group has been doing Machinekit on the BBB SBC for far longer and for a while were using the Xenomai kernel but switched to the rtPreempt and is using Preempt_rt v4.9 and provides pre-built images. Do any of the developers here see a reason why this SPI implementation can't work with Machinekit and why it might even be better doing it?
I also like the fact that, IIRC, devs here created QtQuickVCP which is a better UI system for these SBC implementations. I don't see an current docs for Machinekit on rPi4, only and old one for rPi2/3. It's been quite a while since I built Machinekit from source for the BBB so I've not looked at the current state for doing that on the latest rPiOS. On Thursday, February 18, 2021 at 3:43:28 PM UTC-8 Doug LaRue wrote: > For those interested, I've been in comms with the author of Remora and he > has this working. He's been using it on a 3D printer but once setup, I > would think it's a configuration task to set it up to run a 4 axis CNC, a > 2/3 axis laser cutter, etc. > > > On Thursday, February 18, 2021 at 2:44:47 PM UTC-8 Joonas wrote: > >> Realtime isn't about latency but determinism and the standard usb driver >> stack is non-deterministic. I believe there are realtime capable stacks for >> usb devices but it needs to be supported by both devices. And I don't think >> most mcus support it. >> >> If you don't care about the smoothness of tour motion or use a buffered >> approach, usb works fine. >> >> On Fri 19. Feb 2021 at 0.36, justin White <blaz...@gmail.com> wrote: >> >>> It's not that simple. USB2 has higher latencies, true, but if you are OK >>>> with them, then the USB2 interface is as capable of real-time >>>> communication >>>> as any other interface. There have been attempts to mitigate these >>>> latencies with various results. (Search research papers online.) USB3 >>>> should be much better in this regard. >>>> >>> >>> I dont see how that's true when the default USB2 polling rate is 8ms. >>> You can change the mouse driver to get 1ms but I don't know that the RT >>> patches touch USB. So whats the secret sauce to getting RT USB if the >>> polling interval remains at 8ms on a shared bus? >>> >>> USB3 isn't really even worth talking about yes its peer to peer with >>> much better latency but an rpi4 having a USB3 port doesn't do any good when >>> MCUs really do not. Most MCUs bake usb2 hardware right onto the chip while >>> usb3 is generally a PCIE lane attached to a PHY which I have yet to see on >>> any dev boards. >>> >>> So what's the secret sauce to RT USBx? And .......why, when any MCU >>> contains fast UARTs, spi and sometimes ethernet. >>> >>> On Thu, Feb 18, 2021 at 11:23 AM cern via Machinekit < >>> machi...@googlegroups.com> wrote: >>> >>>> Hello, >>>> >>>> Feb 18, 2021, 14:32 by joonas....@gmail.com: >>>> >>>> > USB itself isn’t realtime capable so it can’t be used for any >>>> realtime tasks. >>>> > >>>> It's not that simple. USB2 has higher latencies, true, but if you are >>>> OK with them, then the USB2 interface is as capable of real-time >>>> communication as any other interface. There have been attempts to mitigate >>>> these latencies with various results. (Search research papers online.) >>>> USB3 >>>> should be much better in this regard. >>>> >>>> Cern. >>>> >>>> > >>>> > On Thu 18. Feb 2021 at 11.18, > ozzy...@gmail.com> <> >>>> ozzy...@gmail.com> > wrote: >>>> > >>>> >> Be interesting to see more details on the Linuxcnc\USB\MESA setup. >>>> >> As far as I was aware there was no RT support for USB. >>>> >> I'm not even sure if MESA themselves recommend their USB boards for >>>> use with Linuxcnc. >>>> >> >>>> >> On Thursday, February 18, 2021 at 7:32:57 AM UTC+11 >> >>>> doug....@gmail.com>> wrote: >>>> >> >>>> >>> Great, thanks for finding it! >>>> >>> >>>> >>> I've seen lots of people purchasing 3DP controller boards to >>>> upgrade 3DP/Lasers/CNC's(consumer stuff) and many of them also use an rPi >>>> with OctoPrint or CNCjs, GridBot etc. >>>> >>> I like this approach in that all of my macines(4 3DPs, 2 laser >>>> cutters and 1 CNC) all have consumer grade controllers in them running on >>>> different uCPUs. Some AVR328, STM32, LPC17xx and one a BBB/CRAMPS. >>>> >>> But would love to be able to have LinuxCNC/Machinekit on an rPi >>>> doing the control, UI, setup. >>>> >>> On Wednesday, February 17, 2021 at 11:02:18 AM UTC-8 >>> >>>> ce...@tuta.io <>>>> wrote: >>>> >>> >>>> >>>> Hi, >>>> >>>> the code is available in >>>> >>>> https://github.com/scottalford75/Remora>>>> - looks like he though >>>> that spiPRU is not a great name and changed it to something more flashy. >>>> >>>> >>>> >>>> Looks interesting from programming point of view, but I wonder how >>>> many people would buy Smoothieboard and RPi both to run 3D printer with >>>> LinuxCNC on it? Most will stay with Smoothie, I think. >>>> >>>> >>>> >>>> Cern. >>>> >>>> >>>> >>>> Dne úterý 16. února 2021 v 19:18:20 UTC+1 uživatel >>>> >>>> doug....@gmail.com <>>>>> napsal: >>>> >>>> >>>> >>>>> I was about to start on setting up a Xylotex BareBoneCNC with a >>>> BBB/Machinekit and thought I'd look at what's going on with Raspberry Pi >>>> in >>>> CNC world. I found a video of a guy driving a Mesa board over USB with >>>> LinuxCNC and it looked impressive(doesn't take much). >>>> >>>>> >>>> >>>>> Got to wondering if a standard 3DP controller like SKR, >>>> Smoothieboard, etc couldn't run firmware similar to the MESA board and >>>> only >>>> found mention of this spiPRU but no details, code, anything. >>>> >>>>> >>>> >>>>> https://github.com/scottalford75/LinuxCNC-on-RPi >>>> >>>>> >>>> >>>>> I searched for spiPRU here and in general inter-web lands and >>>> found nothing but the mention of it in the above git repo. If anyone knew >>>> about it I figured they would be here. >>>> >>>>> Thx >>>> >>>>> >>>> >> >>>> >> >>>> >> >>>> >> -- >>>> >> website: >> http://www.machinekit.io>> blog: >> >>>> http://blog.machinekit.io>> github: >> https://github.com/machinekit >>>> >> --- >>>> >> You received this message because you are subscribed to the Google >>>> Groups "Machinekit" group. >>>> >> To unsubscribe from this group and stop receiving emails from it, >>>> send an email to >> machinekit+...@googlegroups.com>> . >>>> >> To view this discussion on the web visit >> >>>> https://groups.google.com/d/msgid/machinekit/cc241b97-47bb-48d0-b3b4-e595dc809b55n%40googlegroups.com >>>> >>>> < >>>> https://groups.google.com/d/msgid/machinekit/cc241b97-47bb-48d0-b3b4-e595dc809b55n%40googlegroups.com?utm_medium=email&utm_source=footer>>> >>>> >>>> . >>>> >> >>>> > -- >>>> > Terv, >>>> > Joonas Forsell >>>> > >>>> > >>>> > >>>> > -- >>>> > website: > http://www.machinekit.io> blog: > >>>> http://blog.machinekit.io> github: > https://github.com/machinekit >>>> > --- >>>> > You received this message because you are subscribed to the Google >>>> Groups "Machinekit" group. >>>> > To unsubscribe from this group and stop receiving emails from it, >>>> send an email to > machinekit+...@googlegroups.com> . >>>> > To view this discussion on the web visit > >>>> https://groups.google.com/d/msgid/machinekit/CA%2B%2BSnhq%3D-rmGD2z8ewbQ9ryBoyWgwymJTbmWp6NKnGPyhmsrbw%40mail.gmail.com >>>> >>>> < >>>> https://groups.google.com/d/msgid/machinekit/CA%2B%2BSnhq%3D-rmGD2z8ewbQ9ryBoyWgwymJTbmWp6NKnGPyhmsrbw%40mail.gmail.com?utm_medium=email&utm_source=footer>> >>>> >>>> . >>>> > >>> >>> >>>> >>>> -- >>>> website: http://www.machinekit.io blog: http://blog.machinekit.io >>>> github: https://github.com/machinekit >>>> --- >>>> You received this message because you are subscribed to the Google >>>> Groups "Machinekit" group. >>>> To unsubscribe from this group and stop receiving emails from it, send >>>> an email to machinekit+...@googlegroups.com. >>>> To view this discussion on the web visit >>>> https://groups.google.com/d/msgid/machinekit/MTpwssk--3-2%40tuta.io. >>>> >>> -- >> Terv, >> Joonas Forsell >> > -- website: http://www.machinekit.io blog: http://blog.machinekit.io github: https://github.com/machinekit --- You received this message because you are subscribed to the Google Groups "Machinekit" group. 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