diff --git a/app/src/main/cpp/MicroPhoto.cpp b/app/src/main/cpp/MicroPhoto.cpp
index 1793cdc2..84a1ff20 100644
--- a/app/src/main/cpp/MicroPhoto.cpp
+++ b/app/src/main/cpp/MicroPhoto.cpp
@@ -646,3 +646,13 @@ Java_com_xypower_mpapp_MicroPhotoService_setCam3V3Enable(
     GpioControl::setCam3V3Enable(enabled != JNI_FALSE);
 }
 
+extern "C" JNIEXPORT jstring JNICALL
+Java_com_xypower_mpapp_MicroPhotoService_getSerialNumber(
+        JNIEnv* env,
+        jclass cls) {
+
+    char value[PROP_VALUE_MAX] = { 0 };
+    __system_property_get("ro.serialno", value);
+    return env->NewStringUTF(value);
+}
+
diff --git a/app/src/main/java/com/xypower/mpapp/MainActivity.java b/app/src/main/java/com/xypower/mpapp/MainActivity.java
index 692d4a16..d9294268 100644
--- a/app/src/main/java/com/xypower/mpapp/MainActivity.java
+++ b/app/src/main/java/com/xypower/mpapp/MainActivity.java
@@ -184,7 +184,11 @@ public class MainActivity extends AppCompatActivity {
         Log.d(TAG, "MainActivity: reboot=" + rebootFlag + " noDelay=" + noDelay);
 
         MicroPhotoContext.AppConfig appConfig = getAppConfig();
-        binding.cmdid.setText(appConfig.cmdid);
+        if (TextUtils.isEmpty(appConfig.cmdid)) {
+            binding.cmdid.setText(MicroPhotoService.getSerialNumber());
+        } else {
+            binding.cmdid.setText(appConfig.cmdid);
+        }
         binding.server.setText(appConfig.server);
         binding.port.setText(appConfig.port != 0 ? Integer.toString(appConfig.port) : "");
         String protocolStr = appConfig.protocol + "-";
diff --git a/app/src/main/java/com/xypower/mpapp/MicroPhotoService.java b/app/src/main/java/com/xypower/mpapp/MicroPhotoService.java
index d27f4752..5f628a7e 100644
--- a/app/src/main/java/com/xypower/mpapp/MicroPhotoService.java
+++ b/app/src/main/java/com/xypower/mpapp/MicroPhotoService.java
@@ -1034,6 +1034,7 @@ cellSignalStrengthGsm.getDbm();
     protected native void recordingFinished(long handler, boolean result, String path, long videoId);
     public static native void setOtgState(boolean enabled);
     public static native void setCam3V3Enable(boolean enabled);
+    public static native String getSerialNumber();
 
     ////////////////////////GPS////////////////////
     private static final String GPS_LOCATION_NAME = android.location.LocationManager.GPS_PROVIDER;