0784名無しさん@お腹いっぱい。
2018/01/31(水) 20:41:14.77ID:uKX9yO3Ihttp://marlinfw.org/docs/gcode/M081.html
M81 - Power Off
Turn off the high-voltage power supply. If the board is not powered from another source, this may also shut down the electronics.
Usage
M81
Notes
Requires POWER_SUPPLY and a digital pin connected to the PSU’s enable pin.
このあたりを使うのが素直な感じがします