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] <javascript:>. 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.
