Button for Pausing and Resuming (Or Stop, Start) Standby

I have my 3d printer view and some buttons on a screen. I use it to see what the printer is doing e.t.c.

BUT: I would like to pause standby, and later resume it when printing is finished.

Why: So screen savers or dimming wont occur while i am printing.

So: I would like a button that i can place anywhere on the screen to pause and resume standby.