Thanks for feedback.  I didn't realize that linuxcnc was using the PRU.

I will look into that code.
 On 2013-10-18 6:46 PM, "Charles Steinkuehler" <[email protected]>
wrote:

> On 10/18/2013 5:22 PM, Paul Tan wrote:
> > In case anyone's wondering why I'm trying to get really short pulses, I'm
> > trying to connect an iGaging DRO slides to a BeagleBone Black (yeah, I'm
> > trying to CNC my lathe using a DRO closed loop servo with my Dual Motor
> > Controller Capes).  Scoping out my iGaging DRO, I found that the builtin
> > controller uses 24uS pulses with a 128uS duty cycle.  I'm working off of
> > Yuriy's work on the Arduino (
> http://www.yuriystoys.com/p/android-dro.html),
> > but trying it on the BeagleBone.
>
> For fairly short duration pulses like that, you may want to consider
> using the PRU to handle generating the pulses.  It looks like the stuff
> you're working from is already divided between the UI (handled by Linux)
> and the low-level comms (handled by an Arduino).  Basically, you can
> migrate the Arduino stuff to the PRU and probably have less overall hassle.
>
> I have some example code for step/dir pulses and PWM using the PRU
> driving GPIO pins as part of LinuxCNC.  I also have some timing details
> on PRU read and write latency when talking to the GPIO registers:
>
>
> https://github.com/cdsteinkuehler/linuxcnc/blob/MachineKit-ubc/src/hal/drivers/hal_pru_generic/pru_generic.p#L135
>
> --
> Charles Steinkuehler
> [email protected]
>
> --
> For more options, visit http://beagleboard.org/discuss
> ---
> You received this message because you are subscribed to a topic in the
> Google Groups "BeagleBoard" group.
> To unsubscribe from this topic, visit
> https://groups.google.com/d/topic/beagleboard/SLaa4HiC99A/unsubscribe.
> To unsubscribe from this group and all its topics, send an email to
> [email protected].
> For more options, visit https://groups.google.com/groups/opt_out.
>

-- 
For more options, visit http://beagleboard.org/discuss
--- 
You received this message because you are subscribed to the Google Groups 
"BeagleBoard" group.
To unsubscribe from this group and stop receiving emails from it, send an email 
to [email protected].
For more options, visit https://groups.google.com/groups/opt_out.

Reply via email to