Ok I did try using the read_gpio and write_gpio.

The raster component reads the stepgen-fb position and then updates its
output power based up on that, which is wired to a pwmgen.

Would read_gpio and write_gpio affect the pwmgen output?

On Tue, Feb 7, 2017 at 1:43 PM, Peter C. Wallace <[email protected]> wrote:

> >
> > As part of my laser engraver implementation that I have been working on,
> I
> > have a raster component that needs to vary the pwmgen output at higher
> rate
> > than the servo period.
> >
> > The math I'm using to determine the speed is the scan speed. So for
> > instance a 6000mm/min scan speed, with an update rate of 1Khz gives me a
> > resolution of about 0.1mm.  Thus 10Khz will give me 0.01mm resolution at
> > that speed, and allows me to bump up the speed without losing resolution.
> >
> > 6000 / 60 / 1000 = 0.1mm
> >
> >
> >
> > For me a base-thread at about 100000 ns will work. So the idea I had was
> to
> > put my raster components and the hostmot2 stepgens and pwmgen update
> > functions to run on the base thread, while normal motion work still
> occurs
> > on the servo thread.
>
> AFAIK if you have multiple threads, you can only manipulate GPIO at the
> base
> thread rate using the hm2_<BoardType>.<BoardNum>.read_gpio and
> hm2_<BoardType>.<BoardNum>.write_gpio
>
> functions
>
> Also this only works on PCI interfaced cards (not EPP,SPI,Ethernet)
>
> The proper way to do this is probably with motion synchronized data
> painting
> firmware/driver/interpreter changes
>
> >
> > I was able to set up the hal properly and assign the write and read
> methods
> > to the base thread.
> >
> > Now though the steppers now aren't operating properly. When operating
> they
> > are jerky and louder. They seem to want to run in one direction but seize
> > up when running in the other direction.
> >
> > I'm not sure where to start to debug this. Any tips are welcome.
> >
> >
> > Thanks!
> > ------------------------------------------------------------
> ------------------
> > 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
> >
>
> Peter Wallace
> Mesa Electronics
>
> (\__/)
> (='.'=) This is Bunny. Copy and paste bunny into your
> (")_(") signature to help him gain world domination.
>
>
> ------------------------------------------------------------
> ------------------
> 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
>
------------------------------------------------------------------------------
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

Reply via email to