 }
 
 void loop() { 
-  // send command packet to RDM880
+  // send command packet to RDM880 to read serial number every second
   RDM880.write(get_readID, 8);
   delay(100);
   digitalWrite(ledPin, LOW);
   response[7] = NULL;
   standby = true;
 
-  // read response from RDM880 and print
+  // read response packet from RDM880 and print
   int i = 0;
   while(RDM880.available()) {
     response[i] = RDM880.read();

        endTime = (millis() - startTime)/1000;
        if (endTime != 0) {
          Serial.print("Elapsed time: ");
          Serial.println(endTime);
        }
        previousState = signalState;
        standby = true;

      Elapsed time

   Operation:
      Reader waits until a tag is scanned, then prints the serial number of the tag.
      Reader now waits for "control" signal, and when that signal goes high, counts time.

*/

