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.
