diff --git a/app/src/main/cpp/SensorsProtocol.cpp b/app/src/main/cpp/SensorsProtocol.cpp
index c57bff12..69624008 100644
--- a/app/src/main/cpp/SensorsProtocol.cpp
+++ b/app/src/main/cpp/SensorsProtocol.cpp
@@ -1901,7 +1901,7 @@ void CameraPhotoPortDataProcess(SIO_PARAM_SERIAL_DEF *curserial)
 			iNo = rtumsg.MsgData[i + 1] + rtumsg.MsgData[i] * 256;
 			if((0xFF == rtumsg.MsgData[i+2]) && (3 == datalen))
 			{
-				curserial->SerialCmdidx = iNo + 1;
+				curserial->SerialCmdidx = iNo;
 				break;
 			}