 // command packet - start, address, data length, command, data[0 to 2], end
 // response packet when idle - 0xAA, 0x00, 0x02, 0x01, 0x83, 0x80, 0xBB
 char get_readID[] = { 0xAA , 0x00, 0x03, 0x25, 0x26, 0x00, 0x00, 0xBB };
-byte response;
-
+byte response[11];
 const int ledPin = 13;
 
 void setup() {

#include <SoftwareSerial.h> 

SoftwareSerial RDM880(2, 3);
char txrxbuffer[255];

}

void loop() { 
  // send command packet to RDM880
  RDM880.write(get_readID, 8);
  delay(100);
  digitalWrite(ledPin, LOW); 
  response[7] = 0xFF;

  // read response from RDM880 and print
  int i = 0;
  while(RDM880.available()) {
    response[i] = RDM880.read();
    Serial.print(response[i], HEX);
    Serial.print(" ");
    i++;

    // LED on if an RFID is detected
    if(response[7] != 0xFF) {
      digitalWrite(ledPin, HIGH);
    }
  }
  Serial.println();
}
