diff --git a/mpmaster/src/main/res/layout/activity_main.xml b/mpmaster/src/main/res/layout/activity_main.xml
index 611c13a8..673ecfbc 100644
--- a/mpmaster/src/main/res/layout/activity_main.xml
+++ b/mpmaster/src/main/res/layout/activity_main.xml
@@ -65,4 +65,23 @@
         app:layout_constraintStart_toStartOf="parent"
         app:layout_constraintTop_toBottomOf="@+id/btnTurnOtgOn" />
 
+    <Button
+        android:id="@+id/btnTurn485On"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginStart="12dp"
+        android:layout_marginTop="12dp"
+        android:text="485 On"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintTop_toBottomOf="@+id/btnTurnAppOn" />
+
+    <Button
+        android:id="@+id/btnTurn485Off"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_marginStart="12dp"
+        android:text="485 Off"
+        app:layout_constraintStart_toEndOf="@+id/btnTurn485On"
+        app:layout_constraintTop_toTopOf="@+id/btnTurn485On" />
+
 </androidx.constraintlayout.widget.ConstraintLayout>
\ No newline at end of file