Extreme simple system for auto turn off atx power supply requested by Shauki 2 week ago.
Need modify marlin_main.cpp
1 turn on via switch.
2 after bootstrap or ramps or during printing enable pin58 (depend on modify on marlin_main.cpp)
3 now can turn off power swith (if using push button and autoenable pin can hold it for 7 second (bootstrap time of mega) )
4 in end-gcode ad command for turn off pin58
tested and work .