Excellent. I was worried I might run out of pins or performance but neither seems to be an issue.
Thanks a lot for the info - and thanks for writing the driver in the first place! On Tue, 20 Aug 2019 15:42:09 -0500 Charles Steinkuehler <[email protected]> wrote: > On 8/20/2019 11:37 AM, mlampert wrote: > > It seems that hal_pru_generic can use any IO pin as an input or an > > output. Is there still any advantage to use one of the PRU specific > > io pins? > > There is little to no value in using PRU direct output pins vs. GPIO > pins for output signals (eg: step/dir/pwm). > > There is still a strong preference to use the PRU direct input pins, > which can be read "instantly" (1 PRU clock) vs. reading from the GPIO > registers which stalls the PRU core for a few hundred nS while the > read makes it's way through the on-chip interconnect fabric. > > Note the PRU encoder component requires the use of PRU direct inputs > for this reason. > > > Also, I read somewhere that MK can only use one pru. Assuming that > > is correct, does anybody know where the restriction comes from? > > It isn't really a restriction so much as there has not been anyone who > needed/wanted to use both PRUs. I had planned a "non-generic" version > of PRU code to do _really_ high-speed step generation or encoder > monitoring, but it was never really necessary...the hal_pru_generic > code runs fast enough for most of what I need (and often faster than > the stepper drivers will support!). > > I do have a personal setup with the hal_pru_generic code running on > one PRU and custom PRU code running on the other PRU (making use of > the PWM & UART present in the PRU module to generate some custom pulse > sequences), so it's definitely possible. > -- 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 [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/machinekit/20190820195704.62b59e18%40yolanda.
