RFID Library (14 bytes)

This revised version now decodes cards (or badges) that transmit 14 bytes, whereas the previous version handled only 5 bytes.

This library only support TTL RS232 serial port.

Grove - 125KHz RFID Reader

Example:

• When reading the data from some RFID card, you will get data like 2 30 32 30 30 36 41 44 42 34 46 46 43 3 (2 and 3 indicate the start and stop of a transmission; we are going to ignore them).

• Each numbers are is a ASCII character in HEX: 30 32 30 30 36 41 44 42 34 46 46 43 ==> 0 2 0 0 6 A D B 4 F F C

• And need to be reunited in pairs: 0 2 0 0 6 A D B 4 F F C ==> 02 00 6A DB 4F FC

• FC is the checksum using XOR: 02^00^6A^DB^4F == FC

• 02 00 6A DB 4F are your card number: last four bytes (00 6A DB 4F) are the engraved number on the card

• 00 6A DB 4F: engraved number can be retrieved by converting hexadecimal to base-ten (00 6A DB 4F(hex) = 00000000 01101010 11011011 01001111(bin) = 0007002959(dec))

Pins

1. VCC support 3.3 ~ 5V
2. TX, RX connect to Arduino or Seeeduino
3. T1, T2 is the Signal port for RFID antenna
4. W0, W1 is for wiegand protocol, but this library not support yet.

     		+-----------+
++++++++----|VCC	  T1|----
|  +++++----|GND	  T2|----
|  | |++----|TX		 SER|----
|  | |	----|RX		 LED|----	
|  | |	----|W0		BEEP|----
|  | |	----|W1		 GND|----
|  | |		+-----------+
|  | \___________________________________
|  |_____________________________        |
|                                |       |
|                              + + + + + + + +  + + + + + + + +
|                              | | | | | | | |  | | | | | | | |
|                              | | | | | | | |  | | | | | | | |
|            +-----------------|-|-|-|-|-|-|-|--|-|-|-|-|-|-|-|-+
|            |                 x-x-x-x-x-x-x-x  x-x-x-x-x-x-x-x |
|            |              xxx                                 |
|       +--------+          xxx    --- ---    .............     |
|       |        |                | - x + |  ' |  ||\ |.-. '    +
|       |        |          ^      --- ---   | |__|| \|._. |     x
|       |        |        <+++>    ARDUINO   '.............'      +
|       +--------+          V                                     |
|            |            _____                       ++-++   xx  |
|            |           <_____>                      +-O-+   xx  |
|            |                                        ++-++   xx  |
|            |+--++--                                             |
|            ||||++--                  +---------------------+    |
|            |+--++--                  |                     |    |
|            |                         |                     |    |
|         ++------+                    +---------------------+    |
|         ++      |                                               +
|         ++      |          +-+ +-+                             x
|         ++------+          +-+ +-+   x-x-x-x-x-x x-x-x-x-x-x  +
|            +-------------------------|-|-|-|-|-|-|-|-|-|-|-|--+
|                                      | | | | | | | | | | | |
|                                      | | | | | | | | | | | |
|                                      + + + + + + + + + + + +
|____________________________________________|
	

Usage

Connecting RFID Reader RX, TX to Arduino pin headers.

RX <--> 10 TX <--> 11

// RFID_UART.ino

#include <SoftwareSerial.h>
#include <SeeedRFID.h>

#define RFID_RX_PIN 10
#define RFID_TX_PIN 11

#define TEST

SeeedRFID RFID(RFID_RX_PIN, RFID_TX_PIN);
RFIDdata tag;

void setup() {
	Serial.begin(57600);
	Serial.println("Hello, double bk!");
}

void loop() { 
	if(RFID.isAvailable()){
		tag = RFID.data();
		Serial.print("RFID card number: ");
		Serial.println(RFID.cardNumber());
#ifdef TEST
	Serial.print("RFID raw data: ");
	for(int i=0; i<tag.dataLen; i++){
	    Serial.print(tag.raw[i], HEX);
	    Serial.print('\t');
		}
#endif
	}
}

Using multiple readers

When using multiple readers, you'll need to call the 'listen' function in order to receive any future readings.

// RFID_UART.ino

#include <SoftwareSerial.h>
#include <SeeedRFID.h>

#define RFID_RX_PIN 10
#define RFID_TX_PIN 11

#define RFID2_RX_PIN 12
#define RFID2_TX_PIN 13


SeeedRFID RFID(RFID_RX_PIN, RFID_TX_PIN);
RFIDdata tag;

SeeedRFID RFID2(RFID2_RX_PIN, RFID2_TX_PIN);
RFIDdata tag2;

void setup() {
  Serial.begin(9600);
  RFID.listen(); //first, we listen for data on reader #1
}

void loop() { 

  if(RFID.isAvailable()){
    tag = RFID.data();
    Serial.print("RFID card number: ");
    Serial.println(RFID.cardNumber());
    RFID2.listen(); //now start listening for data on reader #2
  }

  if(RFID2.isAvailable()){
    tag2 = RFID2.data();
    Serial.print("RFID2 card number: ");
    Serial.println(RFID2.cardNumber());
    RFID.listen(); //then we listen to reader #1 again...
  }
}

For more information please visit wiki.

---

The original library was written by Ye Xiaobo for seeed studio
and is licensed under The MIT License.
This modified library was written by Adrien FALLOT.

Contributing to this software is warmly welcomed. You can do this basically by
forking, committing modifications and then pulling requests (follow the links above
for operating guide). Adding change log and your contact into file header is encouraged.
Thanks for your contribution.

Seeed Studio is an open hardware facilitation company based in Shenzhen, China.
Benefiting from local manufacture power and convenient global logistic system,
we integrate resources to serve new era of innovation. Seeed also works with
global distributors and partners to push open hardware movement.