writer = peripheral.wrap("rfid writer_0");
reader = peripheral.wrap("rfid reader_0");
redside = "back";

label = "GateKey";
data = "this is the gate key";
range = 5;

print("Simple in-secure RFID door!");
print("Key name: " .. label);
print("Scanning Range " .. range);

function main()
while true do
  if writer.isPresent() and (not writer.isCoded()) and (writer.getProgress() == -1) then
    writer.encode(data,label);
  end
  redstone.setOutput(redside,readerloop());
  os.sleep(.5); --let the redstone settle
  os.queueEvent("marker_event"); --clear the event stack
  repeat
    e = os.pullEvent();
  until e == "marker_event";
end
end

function readerloop()
  reader.scan(range);
  while true do
    e,p1,p2,p3,p4,p5 = os.pullEvent()
    if e == "rfid_detected" and p1 == data then
      return true;
    elseif e == "rfid_scan_done" then
      return false;
    end
  end
end

main()