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 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 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]> wrote: > Black. 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]> wrote: > > Which BeagleBoard are you using? > > Jon > > On Thu, Jan 14, 2021 at 2:51 PM [email protected] <[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 >> --- >> 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]. >> 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 > --- > 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]. > 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 > --- > 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]. > 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 --- 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]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/CAG99bkr3Uo18Mx57p-m2ec2bfi0A%2BKjYMJYNb-bd5sMfKNpRzg%40mail.gmail.com.
