From 2eed566e4b53e5dde2e40fad4938d6625772e340 Mon Sep 17 00:00:00 2001 From: Ben Hardill Date: Fri, 20 Jun 2014 11:04:16 +0100 Subject: [PATCH] Added permisions section to readme.md --- hardware/powermate/README.md | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/hardware/powermate/README.md b/hardware/powermate/README.md index efae74b9..3e42dab2 100644 --- a/hardware/powermate/README.md +++ b/hardware/powermate/README.md @@ -20,4 +20,15 @@ This node outputs messages for 3 different events For the first 2 the message payload of 'up' or 'down' respectively is published to the topic + '/button'. For the wheel rotation the message payload is +ve for clockwise and -ve for anti-clockwise on the topic + '/wheel' +Permissions +----- +Depending on OS, you may get an error that looks something like + + cannot open device with path 0001:0004:00 + +If this happens, it is likely because your user doesn't have permissions for the PowerMate device. In Linux (specifically Raspbian), creating the file /etc/udev/rules/95-powermate.rules and entering the following text: + + SUBSYSTEM=="usb", ATTRS{idVendor}=="077d", ATTRS{idProduct}=="0410", SYMLINK+="powermate", MODE="660", GROUP="input" + +will assign the PowerMate device to the "input" group, which the pi user belongs to. For other OSs, change the GROUP entry to a group that your user belongs to.