Read/Decode EM4100 RFID card

Hi All,

I'm trying to read a 125Khz RFID card from my own reader and decode the data in to meaningful number that is printed on the back of this card,

|500x322

Now, i know the second part (089,47544) is another representation of the same number(0005880248).

For the decoding part, i'm following this tutorial

Before i post the binary gibberish that i'm reading from the card, let me encode below card back in to binary using this example so that i can(hope) find the similar pattern in the binary readings,

|500x115

Below are the steps,

  • Convert card number(0005880248) to hex - 0x59B9B8
  • Get last 8 hex numbers and convert in to 4 bit binary - 0000 0000 0101 1001 1011 1001 1011 1000
  • Above binary with even parity bits included - 0000000000010101001010111100101011110001

According to above article and this article, Even after i skip the leading and trailing binary data i should get something similar to this 0000000000010101001010111100101011110001 in somewhere in middle of my data set. But the problem is i don't.

I'm posting my binary data reading here so you can see it by yourself, But be warned, there are lot of data because i kept the reader running for couple of seconds, and ignore the initial bits thats before i place the card near the reader coil,

00011111111111111111111111111111111111111111111111111111111111111111111111001111110001110011110011011110110111111111100001001101011111111001111110001110011110011011110110101111111100001000101011111111001011110001110011100011011110110100111111100001000011011111111001001110001110011100111011110110100011111100001000011011111111001000110001110011100111011110110100001111100001000011011111111001000010001110011100101011110110100000111100001000011011111111001000001001110011100101011110110100000011100001000011001111111001000001101110011100101011110110100000001100001000011001111111001000001111110011100101001110110100000000100001000011001011111001000001111110011100101000110110100000000010001000011001001111001000001110110011100101000010110100000000011001000011001000111001000001110010011100101000000110100000000011101000011001000011001000001110001011100101000000110100000000011111000011001000011001000001110001111100101000000010100000000011111000011001000010001000001110001111100101000000001100000000011110100011001000010011000001110001101100101000000001100000000011110110011001000010011000001110001100100101000000001100000000011110111011001000010010100001110001100010101000000001101000000011110111111001000010010110001110001100011101000000001101100000011110111111001000010010111001110001100011101000000001101110000011110111101001000010010111101110001100011011000000001101111000011110111100101000010010111111110001100011011000000001101111100011110111100111000010010111111110001100011010100000001101111100011110111100111000010010111111110001100011010110000001101111100011110111100110100010010111111110001100011010111000001101111100011110111100110110010010111111111001100011010111100001101111100011110111100110111010010111111111001100011010111110001101111100011110111100110111110010111111111001100011010111111001101111100011110111100110111110010111111111001100011010111111101101111100011110111100110111101010111111111000100011010111111111101111100011100111100110111101110111111111000010011010111111111101111100011100111100110111101110111111111000010011010111111110101111100011100111100110111101101111111111000010011010111111110011111100011100111100110111101101111111111000010011010111111110011111100011100111100110111101101011111111000010001010111111110010111100011100111000110111101101001111111000010000110111111110010011100011100111001110111101101000111111000010000110111111110010001100011100111001110111101101000011111000010000110111111110010000100011100111001010111101101000001111000010000110111111110010000010011100111001010111101101000000111000010000110011111110010000011011100111001010111101101000000011000010000110011111110010000011111100111001010011101101000000001000010000110010111110010000011111100111001010001101101000000000100010000110010011110010000011101100111001010000101101000000000110010000110010001110010000011100100111001010000001101000000000111010000110010000110010000011100010111001010000001101000000000111110000110010000110010000011100011111001010000000101000000000111110000110010000100010000011100011111001010000000011000000000111101000110010000100110000011100011011001010000000011000000000111101100110010000100110000011100011001001010000000011000000000111101110110010000100101000011100011000101010000000011010000000111101111110010000100101100011100011000111010000000011011000000111101111110010000100101110011100011000111010000000011011100000111101111010010000100101111011100011000110110000000011011110000111101111001010000100101111111100011000110110000000011011111000111101111001110000100101111111100011000110101000000011011111000111101111001110000100101111111100011000110101100000011011111000111101111001101000100101111111100011000110101110000011011111000111101111001101100100101111111110011000110101111000011011111000111101111001101110100101111111110011000110101111100011011111000111101111001101111100101111111110011000110101111110011011111000111101111001101111100101111111110011000

Other factors,

I'm using this reader module and disconnected the 125Khz square wave trace and feeding my own 125Khz square wave to the circuit using an Arduino. And the opamp output is similar to the original. I have scoped the output data and it is similar to the original output which i had before disconnect the 125Khz square wave signal line from it's own firmware.

710059B9B829 This is what i read from the above module for above given card. And yes it gives the same data (710059B9B829) even after i injected my own 125Khz signal from Arduino.

Any help would really appreciated.

Hi, did you managed to solve the issue? I'm also reading raw data from RDM and it looks like a lot of garbage.