What is the problem?
Currently, I click my Preheat button but I must guess at the amount of time for the tool and bed to meet the target temp. I like to read email, or something, while I wait. I often forget. So I set a timer.
But I wouldn't have to if my printer beeped when the target temps are met.
I don't know how to write plugins. I don't know gcode.
Has anyone written a plugin or something to do this?
Please remember, I'm not a techy. I don't understand gcode talk (or Jupiterian).