Have you solved the problem that you were having? I am unsure why you are getting the error:
P9_42 pinmux file not found! cape-universala overlay not found I am currently trying to figure out how the PWM pins work in the 4.1+ Kernel and it appears that after each reboot the *pwmchip** links in the */sys/class/pwm/* directory link to different directories in the *ocp* directory. For P9.42, look for the pwmchip link that links to the */sys/devices/platform/ocp/48300000.epwmss/48300100.ecap/pwm/pwmchip? *directory and then your code works for me. Jon On Thursday, March 17, 2016 at 10:47:39 PM UTC-4, Walter Schilling wrote: > > OK, so here is where I am at: > #1 I wrote the following script, and, well it worked great... Until I had > to reboot my machine: > > > > > > > *#!/bin/bash# SE3910 Real Time Systems# PWM Bash shell script.# Author: W. > Schilling# This script will enable PWM on the beaglebone connected to > ECAPPWM0.# It will set the duty cycle to the value passed in, which is a > value between 1 and 10000.* > > > *# Setup the pin as a PWM pin.config-pin P9.42 pwm* > > > *# Export the control for the device, creating the directory structure > that we w$echo 0 > /sys/class/pwm/pwmchip0/export* > > > *# Setup the period for PWM to be 10000 to make things nice and easy to > work wit$echo 10000 > /sys/class/pwm/pwmchip0/pwm0/period* > > > *# Setup the duty cycle to the value passed in as $1echo $1 > > /sys/class/pwm/pwmchip0/pwm0/duty_cycle* > > > *# Enable pwm echo 1 > /sys/class/pwm/pwmchip0/pwm0/enable* > > However, when I rebooted my machine, the pin failed to toggle. I believe > I inadvertently did something with capes that wasn't enabled when I first > tried it. I then tried this script on my home beaglebone, running Robert > Nelson's image bone-debian-8.3-lxqt-4gb-armhf-2016-02-21-4gb.img. This > one, however, fails with the following: > > root@beaglebone:~# ./pwm2.sh 1000 > P9_42 pinmux file not found! > cape-universala overlay not found > run "config-pin overlay cape-universala" to load the cape > ./pwm2.sh: line 12: echo: write error: Device or resource busy > ./pwm2.sh: line 15: /sys/class/pwm/pwmchip0/pwm0/period: No such file or > directory > ./pwm2.sh: line 18: /sys/class/pwm/pwmchip0/pwm0/duty_cycle: No such file > or directory > ./pwm2.sh: line 21: /sys/class/pwm/pwmchip0/pwm0/enable: No such file or > directory > root@beaglebone:~# > > I've tried the following, which results in different errors but still > errors: > root@beaglebone:~# config-pin overlay cape-universaln > Loading cape-universaln overlay > bash: line 0: echo: write error: File exists > Error loading device tree overlay file: cape-universaln > root@beaglebone:~# ./pwm2.sh 1000 > P9_42 pinmux file not found! > cape-universala overlay not found > run "config-pin overlay cape-universala" to load the cape > ./pwm2.sh: line 12: echo: write error: Device or resource busy > ./pwm2.sh: line 15: /sys/class/pwm/pwmchip0/pwm0/period: No such file or > directory > ./pwm2.sh: line 18: /sys/class/pwm/pwmchip0/pwm0/duty_cycle: No such file > or directory > ./pwm2.sh: line 21: /sys/class/pwm/pwmchip0/pwm0/enable: No such file or > directory > root@beaglebone:~# > > Ideas to try next? > > Walt > -- > 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]. > For more options, visit https://groups.google.com/d/optout. > > -- 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/6c3fb83a-7fdb-4856-b218-b5766368f81d%40googlegroups.com. For more options, visit https://groups.google.com/d/optout.
