easy permissions issue running a PrimeSense sensor on a BBB

[dunmatt]

Hello all, I'm trying read from an Xtion Pro connected to a BeagleBone Black. With some minor tweaking (changing "softfp" to "hard" in the Platform.Arm files that came with the clones of https://github.com/OpenNI/OpenNI and https://github.com/PrimeSense/Sensor as well as adding some simlinks to rename compilers to match hard-codings) I've got everything building and I can successfully run the samples, huzzah!

The one remaining kink that I could use some help sorting out, is that the samples only work correctly when I run them as root. When I run them as a user it tells me "Open failed: Failed to open the USB device!" which I take to mean that there's some permissions thing I need to do, but I don't really understand how linux does USB stuff... a nudge in the right direction would be most appreciated.

Edit: Oooh, progress, dmesg informs me that the udev rule is invalid and the message ended with ":7", which I take to be a line number. Line 7 of the relevant udev rule reads:

SYSFS{idProduct}=="0601",SYSFS{idVendor}=="1d27",MODE="666",OWNER="xxx",GROUP="users"

The trick is, all the other lines of that udev rule are exactly the same save the idProduct value, so I'm not sure why the last line would get singled out like that. I'm going to try adding my username as OWNER, I'll edit again to let you know how it goes.

Edit 2: No dice. The error in dmesg is gone but I still can't open the device (especially odd considering that its supposedly 666). Other ideas?

Edit 3: Solved! The problem wasn't that xxx wasn't a user on my system, it was that SYSFS isn't a valid collection. Replacing it with ATTR globally solved the issue! If you find yourself facing something similar, the key to figuring it out was to run udevadm test on the primesense device in /dev/bus/usb to reveal the helpful error message.