diff --git a/mpmaster/src/main/java/com/xypower/mpmaster/MainActivity.java b/mpmaster/src/main/java/com/xypower/mpmaster/MainActivity.java
index acab5cb3..d5077703 100644
--- a/mpmaster/src/main/java/com/xypower/mpmaster/MainActivity.java
+++ b/mpmaster/src/main/java/com/xypower/mpmaster/MainActivity.java
@@ -14,6 +14,7 @@ import android.os.Bundle;
 import android.os.Handler;
 import android.os.StrictMode;
 import android.view.View;
+import android.widget.Switch;
 
 
 import com.dev.devapi.api.SysApi;
@@ -106,6 +107,18 @@ public class MainActivity extends AppCompatActivity {
             }
         });
 
+        findViewById(R.id.btn485ReadMode).setOnClickListener(new View.OnClickListener() {
+            @Override
+            public void onClick(View view) {
+                Switch sw = (Switch)view;
+                if (sw.isChecked()) {
+                    SysApi.set485ReadMode();
+                } else {
+                    SysApi.set485WriteMode();
+                }
+            }
+        });
+
 
         startMicroPhotoService(getApplicationContext());
     }
diff --git a/mpmaster/src/main/res/layout/activity_main.xml b/mpmaster/src/main/res/layout/activity_main.xml
index 673ecfbc..40e22db9 100644
--- a/mpmaster/src/main/res/layout/activity_main.xml
+++ b/mpmaster/src/main/res/layout/activity_main.xml
@@ -84,4 +84,13 @@
         app:layout_constraintStart_toEndOf="@+id/btnTurn485On"
         app:layout_constraintTop_toTopOf="@+id/btnTurn485On" />
 
+    <Switch
+        android:id="@+id/btn485ReadMode"
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:text="485Read"
+        app:layout_constraintStart_toEndOf="@+id/btnTurn485Off"
+        app:layout_constraintTop_toTopOf="@+id/btnTurn485On" />
+
+
 </androidx.constraintlayout.widget.ConstraintLayout>
\ No newline at end of file