Try this solution: It worked for me! http://unix.stackexchange.com/questions/118716/unable-to-write-to-a-gpio-pin-despite-file-permissions-on-sys-class-gpio-gpio18
"I have not played with the GPIO pins this way but based on lgeorgets *second* comment and this article<http://falsinsoft.blogspot.ca/2012/11/access-gpio-from-linux-user-space.html>, you must first set the direction of the pin to "out". The direction node is owned by root, so: sudo sh -c 'echo out > /sys/class/gpio/gpio18/direction' sh -c is needed here to execute that command in a root subshell. This is because sudo echo out > direction would execute echo as root, but the redirection (> direction) would be done by your current (non-root) shell. You could also just do this su root. After that you should, hopefully, be able to set value as cameron." On Thursday, September 26, 2013 1:23:11 AM UTC-7, [email protected] wrote: > > > I'm trying to run a simple led blink example like here: > > > http://www.phys-x.org/rbots/index.php?option=com_content&view=article&id=104:lesson-1-beaglebone-black-blink-led&catid=46:beaglebone-black&Itemid=81 > > I'm running a Ubuntu image on my beaglebone black with node 0.8.x. I get > a permission problem that looks like some form of failure to have access to > the pins. I added my user to the dialout group and that didn't work. Then > I added my user to every group I could find and that didn't work either. > The only way I can get the code to run and do the blinking is if I run it > as root. My question is, how do I give my user access to whatever is > needed to reach the pins running as non-root. The permission problem looks > like the following: > > fs.js:338 > return binding.open(pathModule._makeLong(path), stringToFlags(flags), > mode); > ^ > Error: EACCES, permission denied > '/sys/class/leds/beaglebone:green:usr0/trigger' > at Object.fs.openSync (fs.js:338:18) > at Object.fs.writeFileSync (fs.js:756:15) > at Object.f.pinMode > (/home/ubuntu/projects/hello_express/node_modules/bonescript/index.js:132:20) > at Object.<anonymous> > (/home/ubuntu/projects/hello_express/hello_express.js:31:3) > at Module._compile (module.js:449:26) > at Object.Module._extensions..js (module.js:467:10) > at Module.load (module.js:356:32) > at Function.Module._load (module.js:312:12) > at Module.runMain (module.js:492:10) > > Thanks for any help in advance. I'm pretty excited to get this running. > > - Samuel > -- 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.
