RDM6300 RFID

Next, upload the following sketch to your Arduino and open the serial monitor window in the IDE:
// --------------------------------------------------------
#include <SoftwareSerial.h>
SoftwareSerial RFID(2, 3); // RX and TX
int i;
void setup()
{
RFID.begin(9600); // start serial to RFID reader
Serial.begin(9600); // start serial to PC 
}
void loop()
{
if (RFID.available() > 0) 
{
i = RFID.read();
Serial.print(i, DEC);
Serial.print(" ");
}
}
// --------------------------------------------------------

Reading and recognising RFID cards

To do anything with the card data, we need to create some functions to retrieve the card number when it is read and place in an array for comparison against existing card data (e.g. a list of accepted cards) so your systems will know who to accept and who to deny. Using those functions, you can then make your own access system, time-logging device and so on.

Let’s demonstrate an example of this. It will check if a card presented to the reader is on an “accepted” list, and if so light a green LED, otherwise light a red LED. Use the hardware from the previous sketche, but add a typical green and red LED with 560 ohm resistor to digital pins 13 and 12 respectively. Then upload the following sketch:

//-------------------------------------------------------------------------------------------------------------
#include <SoftwareSerial.h>
SoftwareSerial RFID(2, 3); // RX and TX
int data1 = 0;
int ok = -1;
int yes = 13;
int no = 12;

int tag1[14] = {2,52,48,48,48,56,54,66,49,52,70,51,56,3};
int tag2[14] = {2,52,48,48,48,56,54,67,54,54,66,54,66,3};
int newtag[14] = { 0,0,0,0,0,0,0,0,0,0,0,0,0,0}; // used for read comparisons
void setup()
{
RFID.begin(9600); // start serial to RFID reader
Serial.begin(9600); // start serial to PC
pinMode(yes, OUTPUT); // for status LEDs
pinMode(no, OUTPUT);
}
boolean comparetag(int aa[14], int bb[14])
{
boolean ff = false;
int fg = 0;
for (int cc = 0 ; cc < 14 ; cc++)
{
if (aa[cc] == bb[cc])
{
fg++;
}
}
if (fg == 14)
{
ff = true;
}
return ff;
}
void checkmytags() // compares each tag against the tag just read
{
ok = 0; // this variable helps decision-making,
// if it is 1 we have a match, zero is a read but no match,
// -1 is no read attempt made
if (comparetag(newtag, tag1) == true)
{
ok++;
}
if (comparetag(newtag, tag2) == true)
{
ok++;
}
}
void readTags()
{
ok = -1;
if (RFID.available() > 0)
{
// read tag numbers
delay(100); // needed to allow time for the data to come in from the serial buffer.
for (int z = 0 ; z < 14 ; z++) // read the rest of the tag
{
data1 = RFID.read();
newtag[z] = data1;
}
RFID.flush(); // stops multiple reads
// do the tags match up?
checkmytags();
}
// now do something based on tag type
if (ok > 0) // if we had a match
{
Serial.println("Accepted");
digitalWrite(yes, HIGH);
delay(1000);
digitalWrite(yes, LOW);
ok = -1;
}
else if (ok == 0) // if we didn't have a match
{
Serial.println("Rejected");
digitalWrite(no, HIGH);
delay(1000);
digitalWrite(no, LOW);
ok = -1;
}
}
void loop()
{
readTags();
}
// ------------------------------------------------------------------------------------

In the sketch we have a few functions that take care of reading and comparing RFID tags. Notice that the allowed tag numbers are listed at the top of the sketch, you can always add your own and more – as long as you add them to the list in the function checkmytags() which determines if the card being read is allowed or to be denied.

The function readTags() takes care of the actual reading of the tags/cards, by placing the currently-read tag number into an array which is them used in the comparison function checkmytags(). Then the LEDs are illuminated depending on the status of the tag at the reader.