Hi, I am working on ucgui version 3.90 . As you know the componment MemDev was not included in 3.90. So I combine the MemDev code of version 3.24 into 3.90. Some test programs with memdev seems to be run ok. But others such as WIDGET_Effect.c are failed. So my question is What is GUI_USAGE ? I can't understand it. Thanks.