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Topic: Interfacing with Parallax RFID Reader/Writer (Read 21589 times) previous topic - next topic


Nov 27, 2010, 09:00 am Last Edit: Nov 27, 2010, 09:56 am by Bu11Billy Reason: 1
Just wanted to say this does indeed work just make sure of the tag type you are using and use the correct read method. The only thing i cant figure out is how the output of the unique id is suppose to be the same as the whats printed on the side of the card or is it ? because for instance i get an output of (look in the byte column)
BYTE        HEX            CHAR            
10            A            NewLine
51            33            3
67            43            C
48            30            0
48            30            0
67            43            C
69            45            E
50            32            2            
52            34            4
57            39            9
48            30            0
13            D            Carrage return
but the serial printed on the side of the fob is 0013509776
Are they not suppose to be the same ?

Nm i just figured out my mistake but ill leave it here for others the output im not sure of what the first 2 lines are doing the 3C but after that is the HEX equivalent of the decimal number printed on the side of the keyfob in my case.  The first and last line are the start of the tag and end as represented in documentation.  Does anyone know what the first things are representing or is it just something specif set on the tag?

Last edit i swear just wanted to add that the tags are the seed studio ones


Hi Bu11Billy,

could you post your code please ?
i am cracking my head for hours on this now but i can't
get it to read a 125khz card... i am currently using the code that is posted earlier in this topic and the led on the RFID reader turns red for a second or so and then just goes green again.. it seems that it just stops at the
Code: [Select]
is there anything else i need to do other then pass then !RW RFID_READ 32 ?

this is the complete code i am using now :
Code: [Select]
//Interface Arduino USB with Parallax 125 Khz UART RFID Reader/Writer
#include <NewSoftSerial.h>

#define rxPin 19
#define txPin 18

//Reader/Writer Commands
#define RFID_READ  0x01
#define RFID_WRITE 0x02

//Memory Locations for Data
#define DATA_ADDR_0  3
#define DATA_ADDR_1  4

//Error Codes
#define ERR_OK  0x01

NewSoftSerial mySerial(rxPin, txPin);
char statusCode;

void setup()
 pinMode(rxPin, INPUT);
 pinMode(txPin, OUTPUT);
 Serial.println("RFID Read/Write Test");

void loop()
   Serial.println("Reading Tag Data...");
   //1st 4 bytes
   mySerial.print(RFID_READ, BYTE);
   mySerial.print(32, DEC);
      //this is where it halts..
     Serial.print("Read Status:");
     statusCode = mySerial.read();
     if(statusCode == ERR_OK)
       Serial.print("RFID Data:");
       Serial.print(mySerial.read(), BYTE);
       Serial.print(mySerial.read(), BYTE);
       Serial.print(mySerial.read(), BYTE);
       Serial.println(mySerial.read(), BYTE);
       Serial.print("NOT OK. Error Code:");
       Serial.println(statusCode, HEX);

thanks in advance for your help ,



Has anyone managed to interface with this read/writer yet?
I have tried many of things, but I plain and simple cannot get anything.




Jan 23, 2011, 09:15 pm Last Edit: Feb 21, 2011, 06:59 pm by DIXIS Reason: 1

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