You should always write down step by step what you're doing so you have no problems reproducing it in the future . . .
On Fri, Mar 18, 2016 at 1:46 AM, William Hermans <[email protected]> wrote: > Seems like you've not loaded the proper device tree file ( "cape" ) for > the correct PWM - To start off with. > > On Thu, Mar 17, 2016 at 7:47 PM, Walter Schilling <[email protected]> > 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]. >> 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]. For more options, visit https://groups.google.com/d/optout.
