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] <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 --- 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.
