On Tue, Jun 3, 2014 at 1:05 PM, maxmike <maxmikes...@gmail.com> wrote: > > Jason, could you please let me know how you got cape-universal to let you do > pwm? > > If I use the am33xx_pwm and bone_pwm_P9_21 dtbo's I can see > /sys/devices/ocp.3/pwm_test_ > P9_21.11 period polarity and run files. > > If I use the cape-universal instead and config-pin P9_21 as pwm > all I get is a confirmation that it occurred, but I have difficulty finding > the period, polarity, run files.
Well, be sure *NOT* to load the bone_pwm_* dtbo (dt overlays). Instead, you should use the standard Linux sysfs entries for PWM. root@beaglebone:~# config-pin p9.14 pwm root@beaglebone:~# config-pin -q p9.14 P9_14 Mode: pwm root@beaglebone:~# echo 3 > /sys/class/pwm/export root@beaglebone:~# cat /sys/class/pwm/pwm3/run 0 root@beaglebone:~# cat /sys/class/pwm/pwm3/duty_ns 0 root@beaglebone:~# cat /sys/class/pwm/pwm3/period_ns 0 root@beaglebone:~# echo 500000 > /sys/class/pwm/pwm3/period_ns root@beaglebone:~# echo 100000 > /sys/class/pwm/pwm3/duty_ns root@beaglebone:~# echo 1 > /sys/class/pwm/pwm3/run root@beaglebone:~# cat /sys/class/pwm/pwm3/run 1 root@beaglebone:~# cat /sys/class/pwm/pwm3/duty_ns 100000 To figure out the index for performing the export, you need to look at the order the PWMs are placed in the devicetree. I input these into my bone.js file that keeps the board specific info (https://github.com/jadonk/bonescript/blob/427de9494d4f494bd7806ddde10913f1578cdbea/src/bone.js#L271). root@beaglebone:~# node -e "var p=require('bonescript').bone.pins;for(var x in p){if(p[x].pwm)console.log(x+':'+p[x].pwm.sysfs);}" P8_13:6 P8_19:5 P8_34:4 P8_36:3 P8_45:5 P8_46:6 P9_14:3 P9_16:4 P9_21:1 P9_22:0 P9_28:7 P9_29:1 P9_31:0 P9_42:2 > > -- > 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. > 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 beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
