Archive for February, 2007

EIS 2007 program available

Friday, February 16th, 2007

A preliminary program for EIS 2007 is online. I will be presenting in the session on Models for Reasoning from 09:00 to 13:00 on Saturday, March 24.

We sent in the camera-ready version of our paper yesterday, after an unpleasant experience with trying to convert our original LaTeX version to a Word document. Fortunately, it took us less time than expected thanks to Yves who wrote a few Word macros to help with the conversion.

I’m looking forward to the conference. The list of accepted papers seems interesting.

PyGTK GUI for the PhidgetRFID reader

Friday, February 2nd, 2007

I had some fun writing a Python wrapper around libphidgets for an RFID reader we had lying around here. To do so, I used ctypes (”apparantly”::http://ailab.ch/pipermail/libphidgets-discuss/2006-February/000442.html the Python bindings for libphidgets were broken). To check for a connected RFID reader, I interfaced with hal through dbus. Afterwards I created a simple GUI for the device with PyGTK.

Here is the result:

PyGTK GUI for RFID reader

I experienced some weird permissions problems though. The device could only be opened with root privileges. Takis helped me step through libphidgets to see if there was a bug in it. In the end, we solved it by changing the /etc/udev/rules.d/permissions.rules file (in my case it was called 40-permissions.rules). I’m not sure if there are any security problems with this though.

I changed these lines:

# USB devices (usbfs replacement)
SUBSYSTEM=="usb_device", MODE="0664"

to:

# USB devices (usbfs replacement)
SUBSYSTEM=="usb_device", GROUP="plugdev", MODE="0664"

I will probably put the code online when I have some spare time (and after I cleaned it up a bit).