Stupid Simple Arduino LF RFID Tag Spoofer

Step 8 Elephants in the Room

 This project does have a few deficiencies that should be mentioned.  First, since the RFID emulator runs on it's own clock instead of using the one from the magnetic field the reader creates not every serial ID broadcast is received by the broadcaster.  This isn't a huge deal because in my experience they end up matching up close enough every about every second or two.  If you wanted to modify this so it could brute force tag IDs it might be more important that every tag ID is broadcast correctly.

The second issue is the form factor of the antenna.  It should be easy to modify this though by simply collapsing the coil.  At that point though you'll need to use a different calculator that does multi-level coils to figure out how to wind it.

Last, there's the range.  By experimenting with the coil winds and the capacitor you should be able to get a few inches of range.  More range would probably need some type of an amplified coil.

The image for this step is from www.flickr.com/photos/exfordy/123900378/ used under the creative commons license.