Making Things Talk

/*
  Microcontroller RFID Reader
  Language: Wiring/Arduino

  Reads data serially from a Parallax or ID Innovations ID12
  RFID reader.
*/

#define tagLength 10    // each tag ID contains 10 bytes
#define startByte 0x0A  // for the ID Innovations reader, use 0x02
#define endByte 0x0D    // for the ID Innovations reader, use 0x03
#define dataRate 2400   // for the ID Innovations reader, use 9600

char tagID[tagLength];            // array to hold the tag you read
int tagIndex = 0;                 // counter for number of bytes read
int tagComplete = false;          // whether the whole tag's been read

void setup() {
  // begin serial:
  Serial.begin(dataRate);
}

void loop() {
  // read in and parse serial data:
  if (Serial.available() > 0) {
    readByte();
  }
  if(tagComplete == true) {

    Serial.println(tagID);
  }
}

/*
  This method reads the bytes, and puts the
 appropriate ones in the tagID

 */
void readByte() {
  char thisChar = Serial.read();
Serial.print(thisChar, HEX);
  switch (thisChar) {
  case startByte:     // start character
    // reset the tag index counter
    tagIndex = 0;
    break;
  case endByte:    // end character
    tagComplete = true;  // you have the whole tag
    break;
  default:    // any other character
    tagComplete = false;  // there are still more bytes to read
    // add the byte to the tagID
    if (tagIndex < tagLength) {
      tagID[tagIndex] = thisChar;
      // increment the tag byte counter
      tagIndex++;
    }
    break;
  }
}