On Fri, Jan 15, 2021 at 9:25 AM Steve Lentz <stle...@gmail.com> wrote: > > OK, 3 of 4 PWM pins are working, but still no luck with P8_13. > > I can see that Adafruit_BBIO is writing values into > /sys/class/pwm/pwm-7:1/duty_cycle but no output is being generated. > > debian@beaglebone:/sys/class/pwm/pwm-7:1$ cat duty_cycle > 200000 > debian@beaglebone:/sys/class/pwm/pwm-7:1$ cat period > 500000 > > Pin 8_13 can still be used for GPIO. I have not dug further into the device > files. Does this seem like a hardware or software issue? Should I reinstall > the base image, accept that the board is flaky, or is there some other > possible solution? > > Also, the PWM frequency is fixed at 2000 Hz (period = 500000 ns). Is this > intended? I can work with 2000, so this is more out of curiosity. > > Python returns the following errors: > > >>> PWM.start(pin3,50,1000) > Traceback (most recent call last): > File "<stdin>", line 1, in <module> > RuntimeError: Problem with a sysfs file > > >>> PWM.set_frequency(pin3,1000) > Traceback (most recent call last): > File "<stdin>", line 1, in <module> > RuntimeError: Could not write to the frequency file > > Attempting to write into the period file directly returns the following: > > debian@beaglebone:/sys/class/pwm/pwm-7:1$ sudo echo 400000 > period > [sudo] password for debian: > echo: write error: Invalid argument
That's invalid, "sudo echo....." sudo sh -c "echo '400000' >> ./period" Besides, pwm should be "root:gpio" permissoins.. Regards, -- Robert Nelson https://rcn-ee.com/ -- 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/CAOCHtYj8yE89VAqhdrkephL2TKGrX6Csjbou0Noak7ke41xQEA%40mail.gmail.com.
