Stupid Simple Arduino LF RFID Tag Spoofer

Step 3 The Data

You can either download the code below, or get it here: www.scribd.com/doc/30215336/RFID-Faker-Code

The serial number of a tag is sent over using a fairly simple protocol.

It starts by sending 9 one's

Then it sends 10 sets of 4 bits, then one parity bit (it's using even parity)
Then it sends "column" parity bits (even parity of the rows in the previous step)
Last it sends a 0 stop bit

So an example looks like this:

(start bits)
111111111

(10 rows of data - the card serial number)
(the first 4 bits are the data, the last is the even parity bit)

11110
10100
10001
11000
10010
11101
11110
00000
00011
01010

(then it sends the column parity bits, even parity of the rows above)

1101

(last a 0 stop bit)

0

See the pdf in the first link in the references section for more details on this

Image provided by Flickr user at www.flickr.com/photos/kurtisscaletta/2473469841/ and used under the creative commons license.

Comments

[musick7]

LC METER Link, This will help with this project.

http://electronics-diy.com/lc_meter.php

Great Project! Love the simpleness here at Instructables!

[lras]

 Shouldn't the sixth line "11100" be "11101"?  (Zero-happy again? :-)

[sketchsk3tch]

 You're right, thanks for pointing that out.  It should be fixed now.  Let me know if you notice anything else.

[lras]

 Or perhaps it should be "11110" to make the column party correct.