README.md now describes udev-based file permission fix

MantaOSC/README.markdown

@@ -95,3 +95,49 @@ color.
 ### "/manta/led/button"
 
 Takes a color string and an integer representing the pad LED to be set.
+
+Troubleshooting
+===============
+
+If the Manta is not recognised on your system, try to run the program with ```sudo```. If this works, it is a permission problem that can be fixed with a udev rule.
+
+Linux (e.g. Ubuntu)
+-------------------
+
+Add a file to ```/etc/udev/rules.d``` called ```50-manta.conf``` with the following contents:
+```
+SUBSYSTEM=="usb", ATTR{idVendor}=="2424", ATTR{idProduct}=="2424", MODE="0666"
+```
+
+Unplug the Manta, run 
+```
+sudo /etc/init.d/udev restart
+```
+
+then plug in the Manta.
+
+
+Arch Linux
+----------
+
+On Arch Linux, the udev system works a bit different: 
+
+To see the used variables, attach a manta and run the following command
+```
+udevadm info -a -p /sys/class/hidraw/hidraw0
+```
+
+It shows all udev-related items attached to ´´´hidraw0´´´, The manta should show up here.
+According to the udev system description on the [arch linux wiki](https://wiki.archlinux.org/index.php/Udev), config files have to end on ```.rules```. 
+The config file therefore will be something like ```/etc/udev/rules.d/50-manta.rules```
+According to the output of the ```udevadm info``` from above, its content should be something like
+```
+SUBSYSTEMS=="usb", ATTRS{idVendor}=="2424", ATTRS{idProduct}=="2424", MODE="0666"
+```
+
+To reload the udev rules, run
+```
+sudo udevadm control --reload-rules
+```
+
+Re-plug the manta and try MantaOSC again.