The IIO driver uses DMA to transfer samples from the ADC to the buffer, so the CPU utilization is very low. Using the PRU, the ARM processor has to copy the Buffer from the PRU memory to ARM memory, and this causes the ARM CPU utilization to be higher than using the IIO driver. The IIO driver freeze up the PRU to do something more important.
Regards, John > On Sep 22, 2017, at 3:56 PM, Jeff Andich <jeff.and...@gmail.com> wrote: > > Not delving into each implementation, and not knowing anything about the IIO > driver, I would think the PRU implementation would offload the utilization of > the Linux CPU (Arm9?) vs the IIO driver. Is this true? > > Also I thin the posted examples are worthwhile to those interfacing with an > external ADC and to those who are wanting more PRU coding examples.. > > regards and thanks for posting your project! > > jeff > > > > > > On Friday, September 22, 2017 at 11:05:55 AM UTC-5, john3909 wrote: > You do realize that you can achieve the same sample rate with the IIO driver > in Linux? > > Regards, > John > > > > >> On Sep 22, 2017, at 12:07 AM, Arend Lammertink <lam...@gmail.com >> <javascript:>> wrote: >> >> Hi all, >> >> I just wanted to share that I managed to run the ADC unit in a BBG at >> (almost?) 800 kS/sec sampling two channels, which means a total sampling >> rate of 1.6 mS/sec. I forked a small project from rvega and played with the >> code. You can find my code at: >> >> https://github.com/l4m4re/bbb-pru <https://github.com/l4m4re/bbb-pru> >> >> The adc code is in the apps/adc directory. >> >> Perhaps this code is helpful for others, too. The PRU code configures the >> ADC and the current setup samples AIN-1 and AIN-2 at 800 kS/sec. >> >> Regards, >> >> Arend Lammertink. >> >> -- >> For more options, visit http://beagleboard.org/discuss >> <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 beagleboard...@googlegroups.com <javascript:>. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/beagleboard/e343b354-1e28-4b32-bd94-ad20fdd91f1b%40googlegroups.com >> >> <https://groups.google.com/d/msgid/beagleboard/e343b354-1e28-4b32-bd94-ad20fdd91f1b%40googlegroups.com?utm_medium=email&utm_source=footer>. >> For more options, visit https://groups.google.com/d/optout >> <https://groups.google.com/d/optout>. > > > > -- > For more options, visit http://beagleboard.org/discuss > <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 beagleboard+unsubscr...@googlegroups.com > <mailto:beagleboard+unsubscr...@googlegroups.com>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/beagleboard/6f5827cf-85ec-45c9-978a-f4e0d1f1957b%40googlegroups.com > > <https://groups.google.com/d/msgid/beagleboard/6f5827cf-85ec-45c9-978a-f4e0d1f1957b%40googlegroups.com?utm_medium=email&utm_source=footer>. > For more options, visit https://groups.google.com/d/optout > <https://groups.google.com/d/optout>. -- 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 beagleboard+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/BBEC839B-D260-4ED5-96EC-EDF2A0014D9B%40gmail.com. For more options, visit https://groups.google.com/d/optout.
