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This example is for Wiring version 1.0 build 0100+. If you have a previous version, use the examples included with your software. If you see any errors or have comments, please let us know.

RFID reading by BARRAGAN http://barraganstudio.com
Demonstrates how to read data from a Parallax RFID reader connected to the Serial1 serial port and print the tag number through the Serial serial port.

    byte val;
    char code[10];
    int bytesread = 0;

    void setup()
    {
      Serial1.begin(2400);  // RFID reader SOUT pin connected to Serial1 RX pin at 2400bps
      Serial.begin(9600);   // Serial set to 9600
      pinMode(4, OUTPUT);   // Set digital pin 4 as OUTPUT to connect it to the RFID /ENABLE pin
    }

    void loop()
    {
      digitalWrite(4, LOW);                  // Activate the RFID reader
      if (Serial1.available() > 0)           // if data available from reader
      {
        if ((val = Serial1.read()) == 10)    // check for header
        {
          bytesread = 0;
          while (bytesread < 10)             // read 10 digit code
          {
            if (Serial1.available() > 0)
            {
              val = Serial1.read();
              if ((val == 10) || (val == 13)) // if header or stop bytes before the 10 digit reading
              {
                break;                       // stop reading
              }
              code[bytesread] = val;         // add the digit
              bytesread++;                   // ready to read next digit
            }
          }
          if (bytesread == 10)               // if 10 digit read is complete
          {
            Serial.print("TAG code is: ");   // possibly a good TAG
            Serial.println(code);            // print the TAG code
          }
          bytesread = 0;
          digitalWrite(4, HIGH);             // deactivate RFID reader
          delay(1000);                       // wait for a second
        }
      }
    }