 
    Input:
       RFID tag
+      Signal from Pin 4
 
    Output:
       Serial number of tag scanned
+      Elapsed time
 
    Operation:
       Reader waits until a tag is scanned, then prints the serial number of the tag

  digitalWrite(ledPin, LOW); 
  standby = true;
  response[7] = NULL;

  // read response from RDM880 and print
  int i = 0;

      // Machine is ready to fire, get ready to track time
      standby = false;
      elapsed_time = accumulator(standby) / 1000;
      Serial.print("Elapsed Time: ");
      Serial.print(elapsed_time);
      }
    }
  }
