Hardware Reference
In-Depth Information
unplug the mouse before plugging in additional USB devices. Linux is designed so that it can be
used without a mouse from the command line. Follow these steps to test the reader from a com-
mand line:
1.
If you are running a graphical X environment, choose Logout from the program menu.
You will be returned to the command line.
2.
Unplug your mouse and plug in the RFID reader into the USB port.
3.
Start the text-based editor nano (or your preferred text-based text editor) by typing
nano
on the command line.
4.
Bring an RFID tag near to the reader. It should bleep, and you will see a string of char-
acters are typed to the screen. Bring a diferent tag near to the reader and check that a
diferent string of characters is displayed on the next line.
Remember that whenever you present a tag to your reader it will type its serial number
wherever the cursor is, followed by a new line. So don't present a tag when you're in the
middle of typing something else!
5.
Now is a good time to create the data ile that will contain the tags that you want to
grant access to open the door. Still in nano, add the name of the person who will be
given the tag followed by the ID from the tag separated by a comma. here should be a
separate line for each tag. Save the ile by typing Ctrl + X, followed by Y to conirm that
you want to save the bufer, followed by the ilename
tag.txt
and then Enter. Your
tags and reader may produce codes that look slightly diferent, but the ile should look
similar to this:
Andrew,1c477cd5
Mike,54bfc314b
If your RFID reader does not send any data, check that it works with your tags with a desktop
computer. To check that the Raspberry Pi has recognised your USB reader, type
dmesg
into a
terminal shortly after plugging it in and look for a reference to RFID and USB HID.
Experiment with reading other items containing RFID tags, such as ID cards, payment
cards, travel passes and biometric passports. If successful, you should notice that a string of
characters is printed.
