This project consists of several 'modules' that you need to hook up to the Arduino and test in advance. First hook-up the RF reader. You can use the 5v output of the Arduino to power it, and a digital port (I used 2) to get the signal. The RDM630 that I used also has pins for a led that I don't use. It also has an RX pin to send info back to the RF reader, but I don't use that either. Hook-up your antenna, get a tag and use the serial monitor of the Arduino to see if it's detected. Now you can also start working on improving the antenna by trying adding or removing turns, trying different shapes et cetera. Power the Adruino with the 9v power supply, not just USB because at least in my case that didn't work. You can
download the file named 'rfid3.pde' to test. The code requires NewSoftSerial.h which can be obtained
here