@Override
  public void start(Stage primaryStage) {
    primaryStage.setTitle("CoAP Explorer");
    Group root = new Group();
    Scene scene = new Scene(root, 800, 600);

    TextArea hexArea = new TextArea();
    TextArea binArea = new TextArea();

    CoapPacket packet = new CoapPacket();
    packet.setPayload("PAYLOAD");
    packetProp.setValue(packet);

    binArea.textProperty().bindBidirectional(packetProp, new AsciiConverter());

    hexArea.textProperty().bindBidirectional(packetProp, new HexConverter());
    hexArea.setEditable(false);
    hexArea.setFont(javafx.scene.text.Font.font(Font.MONOSPACED));

    VBox vbox = new VBox();
    vbox.setPadding(new Insets(10));
    vbox.setSpacing(8);

    VBox.setMargin(hexArea, new Insets(0, 0, 0, 8));
    vbox.getChildren().add(hexArea);
    VBox.setMargin(binArea, new Insets(0, 0, 0, 8));
    vbox.getChildren().add(binArea);

    root.getChildren().add(vbox);

    primaryStage.setScene(scene);
    primaryStage.show();
  }