Looking forward to the results. Compared to the MESA cards like the 7i92 via Ethernet how well do you think it will handle say a 600 line quadrature encoder? For a small Unimat or Sherline lathe running 8000 RPM is 8000/60 x 2400 = 320,000 edges per second.
One of the reasons that the Arduino based electronic gearing I think uses only 1200 edges and limits RPM to under 2000 which would be at most 40,000 interrupts per second or every 25uS. OTOH, my ELS used only the index pulse and insisted on a stable spindle with minor speed variations and could thread at 6000 RPM not that you'd probably want to. The small lathes are also notorious for having under powered spindles and therefore slowing down as soon as the cut starts. Again not a problem for gear driven or manual turning but does require closed loop feedback for CNC or electronic gearing. John > -----Original Message----- > From: Sam Sokolik [mailto:samco...@gmail.com] > Sent: August 27, 2024 10:11 AM > To: Enhanced Machine Controller (EMC) > Subject: Re: [Emc-users] LinuxCNC 2.9.3 has been released > > (and I meant isolcpus 1,2,3) > > On Tue, Aug 27, 2024 at 12:09�PM Sam Sokolik <samco...@gmail.com> > wrote: > > > I have been goofing around with a rpi5 with the linuxcnc image. The > > latency looks good - but if you set a base thread of 50000ns - it will > > over-run. So - I don't think it is 'as good' as a good pc. > > > > (just idle=poll and isolcpus 2,3,4) > > > > Still playing with tweeks to the rt kernel though - so maybe I can get it > > better. > > > > And - the hal_gpio driver does look very cool to configure the pi i/o > > > > sam > > > > https://photos.app.goo.gl/SqHxLeRUMLD5pMjf8 > > > > On Tue, Aug 27, 2024 at 12:02�PM Chris Albertson < > > albertson.ch...@gmail.com> wrote: > > > >> The Pi5 has very roughly about 70% of the performance of an Intel Core > >> i5-8250U. A lot of people are using Intel-based PCs that are slower and > >> older than the i5. > >> > >> Then, if you are using the Mesa FPGA cards, how much does the Linux > >> computer�s performance matter? > >> > >> Again, the storage device does matter. SD cards are very slow. The Pi5 > >> can use �real� SSD. > >> > >> > >> > On Aug 27, 2024, at 9:37�AM, John Dammeyer > <jo...@autoartisans.com> > >> wrote: > >> > > >> > I've read a posting on another forum where the author states he's > >> running LinuxCNC with a Raspberry Pi using the Pi4 (and now Pi5) I/O pins > >> configured to duplicate the PC parallel port. With the quad core processor > >> on the Pi is it now fast enough to duplicate a PC with a parallel port or > >> is the guy full of BS? > >> > John > >> > > >> >> -----Original Message----- > >> >> From: Chris Albertson [mailto:albertson.ch...@gmail.com] > >> >> Sent: July 13, 2024 11:40 AM > >> >> To: Enhanced Machine Controller (EMC) > >> >> Subject: Re: [Emc-users] LinuxCNC 2.9.3 has been released > >> >> > >> >> If the old Lenovo PC has ahard drive, or better yet an SSD inside,then > >> it will > >> >> run much better then the Pi4 that is runniong off an SD card. Those > >> cards a > >> >> re very slow. > >> >> > >> >> If you want to upgrade the hardware replace th mechanical hard drive > >> in the > >> >> PC with a SATA SSD. If it already has an SSD, then you are good > >> already > >> >> > >> >>> On Jul 13, 2024, at 11:24?AM, John Dammeyer > <jo...@autoartisans.com> > >> >> wrote: > >> >>> > >> >>> > >> >>> > >> >>>> From: andy pugh [mailto:bodge...@gmail.com] > >> >>>> > >> >>>> On Sat, 13 Jul 2024 at 19:00, John Dammeyer > <jo...@autoartisans.com> > >> >>>> wrote: > >> >>>>> > >> >>>>> Hi Andy, > >> >>>>> On my workbench for playing around I'm running 2.8.4 on a Pi4 > with > >> an > >> >> LCD > >> >>>> touch screen and the MESA 7i92H. How easy to update that? > >> >>>> > >> >>>> The best thing to do with a Pi is probably to make a new SD card > from > >> >>>> the LinuxCNC image, then copy your existing config across (probably > >> >>>> easiest to put the linuxcnc folder on a USB stick then swap SD cards) > >> >>>> Then you can always go back to the old, working, SD card if there is > >> a > >> >>>> problem. > >> >>>> > >> >>> > >> >>> Thanks. That's what I figured. > >> >>> What about the 2.8.1 PC? Better to replace it? I picked it up > >> surplus for > >> >> about $75 a number of years ago. I have a second one as a spare. > >> >>> John > >> >>> > >> >>> > >> >>> > >> >>> _______________________________________________ > >> >>> Emc-users mailing list > >> >>> Emc-users@lists.sourceforge.net > >> >>> https://lists.sourceforge.net/lists/listinfo/emc-users > >> >> > >> >> > >> >> > >> >> _______________________________________________ > >> >> Emc-users mailing list > >> >> Emc-users@lists.sourceforge.net > >> >> https://lists.sourceforge.net/lists/listinfo/emc-users > >> > > >> > > >> > > >> > _______________________________________________ > >> > Emc-users mailing list > >> > Emc-users@lists.sourceforge.net > >> > https://lists.sourceforge.net/lists/listinfo/emc-users > >> > >> > >> > >> _______________________________________________ > >> Emc-users mailing list > >> Emc-users@lists.sourceforge.net > >> https://lists.sourceforge.net/lists/listinfo/emc-users > >> > > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
