diff --git a/sdk/Arduino/Arduino-ESP32/Helper.cpp b/sdk/Arduino/Arduino-ESP32/Helper.cpp
index c0ac8344..acaa1005 100644
--- a/sdk/Arduino/Arduino-ESP32/Helper.cpp
+++ b/sdk/Arduino/Arduino-ESP32/Helper.cpp
@@ -461,6 +461,7 @@ String getTime()
     }
     delay(500);
   }
+  return "";
 }
 
 //打印提示信息
diff --git a/sdk/Arduino/Arduino-ESP8266/Helper.cpp b/sdk/Arduino/Arduino-ESP8266/Helper.cpp
index 1a57083d..a782d8e1 100644
--- a/sdk/Arduino/Arduino-ESP8266/Helper.cpp
+++ b/sdk/Arduino/Arduino-ESP8266/Helper.cpp
@@ -450,6 +450,7 @@ String getTime()
     }
     delay(500);
   }
+  return "";
 }
 
 //打印提示信息
diff --git a/sdk/Arduino/WumeiArduino/Auth.cpp b/sdk/Arduino/WumeiArduino/Auth.cpp
index 3705ab93..eb003fed 100644
--- a/sdk/Arduino/WumeiArduino/Auth.cpp
+++ b/sdk/Arduino/WumeiArduino/Auth.cpp
@@ -117,6 +117,7 @@ String getTime()
     }
     delay(500);
   }
+  return "";
 }
 
 /*