I'm looking for udev rules or some other way to read system LEDs without sudo. I tried https://github.com/todbot/blink1/blob/master/linux/51-blink1.rules, but I suspect it's not 100% what I need for the Duo.

what do you want to read?

Or what can be read as usre if you know the trigger? = here heartbeat

 

root@npi-k1-plus(192.168.6.70):~# more /sys/class/leds/nanopi:green:status/trigger
none usb-gadget usb-host kbd-scrolllock kbd-numlock kbd-capslock kbd-kanalock kbd-shiftlock kbd-altgrlock kbd-ctrl
lock kbd-altlock kbd-shiftllock kbd-shiftrlock kbd-ctrlllock kbd-ctrlrlock usbport mmc0 mmc1 mmc2 disk-activity di
sk-read disk-write ide-disk mtd nand-disk [heartbeat] cpu cpu0 cpu1 cpu2 cpu3 activity default-on panic rfkill-any
 rfkill-none rc-feedback rfkill0 0.2:00:link 0.2:00:1Gbps 0.2:00:100Mbps 0.2:00:10Mbps

 

Actually I want to update brightness, but I may want to update trigger as well (sudo works):

 

echo 0 > /sys/class/leds/nanopi\:green\:pwr/brightness
/sys/class/leds/nanopi:green:pwr/brightness: Permission denied

 

Here's my working rc.local (usio is the group I want to give access to):

chown -R root:usio /sys/devices/platform/leds/leds
chmod -R ug+rw /sys/devices/platform/leds/leds