OK, I rechecked and only Pin 8_13 is not working; the other three PWM pins are good using Adafruit.PWM. Pin 8_13 does respond to GPIO.HIGH and GPIO.LOW, so I don’t think I’ve damaged the hardware. Who knows what I have managed to do to the /sys/class files. If it doesn’t clear up on restart, I will reinstall the image. Of course 8_13 is the one I was planning to use, but I can just as well wire something to 8_19 for now.
Thanks for the help. -Steve > On Jan 14, 2021, at 8:00 PM, jonnymo <[email protected]> wrote: > > The SpreadSheet at the following link will show you which pins on the BB > Black can be set for PWM. > > https://docs.google.com/spreadsheets/d/1fE-AsDZvJ-bBwzNBj1_sPDrutvEvsmARqFwvbw_HkrE/edit#gid=1518010293 > > <https://docs.google.com/spreadsheets/d/1fE-AsDZvJ-bBwzNBj1_sPDrutvEvsmARqFwvbw_HkrE/edit#gid=1518010293> > > As far as the Adafruit BBIO libs, have you gone through the example at the > Adafruit site? > https://learn.adafruit.com/setting-up-io-python-library-on-beaglebone-black/pwm > > <https://learn.adafruit.com/setting-up-io-python-library-on-beaglebone-black/pwm> > > If this is not working, could you provide any errors or output of the issue > you are seeing? > > The output of the following might be helpful: > /opt/scripts/tools/version.sh > > Cheers, > > Jon > > > On Thu, Jan 14, 2021 at 4:42 PM Steve Lentz <[email protected] > <mailto:[email protected]>> wrote: > Black. BeagleBoard.org <http://beagleboard.org/> Debian Buster IoT Image > 2020-04-06. > > FWIW, the Adafruit libraries let me control the pins as GPIO. > > > TY, > -Steve > >> On Jan 14, 2021, at 7:02 PM, jonnymo <[email protected] >> <mailto:[email protected]>> wrote: >> >> Which BeagleBoard are you using? >> >> Jon >> >> On Thu, Jan 14, 2021 at 2:51 PM [email protected] <mailto:[email protected]> >> <[email protected] <mailto:[email protected]>> wrote: >> OK, I want to generate a PWM signal to send to a motor controller. This is >> simply to communicate the desired speed, the motor controller will do all >> the heavy lifting. >> >> Unfortunately, the Adafruit_BBIO libraries appear broken and bonescript >> doesn't seem any better. >> >> After digging through Google results I found myself in /sys/class/pwm/ using >> echo to write values into various files and through pure dumb luck was able >> to get a 2 Khz square wave up on a scope and change its duty cycle. So at >> least my set up seems to be working at some level. >> >> However, I feel I am missing a bunch of information. Which pwmchip exports >> to which pwm-X:X and corresponds to which pin? "duty_cycle" is not really >> duty cycle, it is nanoseconds high. I can't change the period, even to >> sensible values like 250000 or 1000000. Some of the information on Stack >> Exchange is worrying, will pwm-4:0 always correspond to P9_14 or can this >> change on boot? >> >> Is there a way to restore the functionality of the Adafruit BBIO libraries, >> short of waiting for an update? I did pip3 install -U. Requirement already >> satisfied: Adafruit_BBIO in /usr/local/lib/python3.7/dist-packages (1.2.0) >> >> If that's not possible, is there any documentation on how the /sys/class/pwm >> is intended to function? >> >> Thank you, >> -Steve Lentz >> >> -- >> 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 [email protected] >> <mailto:[email protected]>. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/beagleboard/08130fba-0f75-464a-9041-d66a1c3a8cacn%40googlegroups.com >> >> <https://groups.google.com/d/msgid/beagleboard/08130fba-0f75-464a-9041-d66a1c3a8cacn%40googlegroups.com?utm_medium=email&utm_source=footer>. >> >> -- >> 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 [email protected] >> <mailto:[email protected]>. >> To view this discussion on the web visit >> https://groups.google.com/d/msgid/beagleboard/CAG99bkoUYXmrUU%2BwtoQnXTYAd3Uq6SAXsTFskbZ-75%2ByvAX3eQ%40mail.gmail.com >> >> <https://groups.google.com/d/msgid/beagleboard/CAG99bkoUYXmrUU%2BwtoQnXTYAd3Uq6SAXsTFskbZ-75%2ByvAX3eQ%40mail.gmail.com?utm_medium=email&utm_source=footer>. > > > -- > 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 [email protected] > <mailto:[email protected]>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/beagleboard/44AF4518-7FEA-4331-9E61-5D442D484D20%40gmail.com > > <https://groups.google.com/d/msgid/beagleboard/44AF4518-7FEA-4331-9E61-5D442D484D20%40gmail.com?utm_medium=email&utm_source=footer>. > > -- > 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 [email protected] > <mailto:[email protected]>. > To view this discussion on the web visit > https://groups.google.com/d/msgid/beagleboard/CAG99bkr3Uo18Mx57p-m2ec2bfi0A%2BKjYMJYNb-bd5sMfKNpRzg%40mail.gmail.com > > <https://groups.google.com/d/msgid/beagleboard/CAG99bkr3Uo18Mx57p-m2ec2bfi0A%2BKjYMJYNb-bd5sMfKNpRzg%40mail.gmail.com?utm_medium=email&utm_source=footer>. -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. 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