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Testing a Phidget RFID Reader
Description: This tutorial shows you how to test a Phidget RFID reader and view tag data changes published to a ROS topic.Keywords: phidgets, rfid
Tutorial Level: BEGINNER
One Time Setup Instructions
The phidgets_ros package calls phidgets_py_api which loads the Phidgets C Api (phidgetspp_c_api). On linux, by default, USB devices are not writeable by anybody but root. This can be solved by following the udev ruleset instructions in the phidgetspp_c_api package. You will need to build this package to get the instructions and the rule file:
$ roscd phidgetspp_c_api $ rosmake
Following the udev instructions in build/Phidgetlinux/README file.
$ sudo cp build/Phidgetlinux/phidget21/udev/*.rules /etc/udev/rules.d/.
then restart udev:
$ sudo /etc/init.d/udev restart
You will also need to set up one last environment variable so that libusb will look at /dev/bus/usb instead of /proc/bus/usb.
$ export USB_DEVFS_PATH=/dev/bus/usb
After this, you should be able to connect your Phidget.
Compiling
Start by compiling the driver:
$ rosmake phidgets_ros
To Run
Run the rfidscan node. (You might be prompted to start roscore in another shell if it is not already running.)
$ rosrun phidgets_ros rfidscan.py
You should see something like this:
Please attach RFID reader now. (waiting 15 seconds)
Connect a Phidget RFID reader using a USB cable to your PC.
Confirming RFID Output
Move the reader over a rfid tag to create data changes. To monitor the changes, echo the rfid ROS topic:
$ rostopic list $ rostopic echo /rfid
You should see something like this:
--- gained: True tag: 15007ED062 --- gained: False tag: 15007ED062 --- gained: True tag: 15007EC21A --- gained: False tag: 15007EC21A
