Support for commands M0

[kaktusus]

Hello
😃

The Marlin Firmware does wait for user to press a button on the LCD, or a specific time. "M0 P2000" waits 2000 milliseconds, "M0 S2" waits 2 seconds.

This will allow you to create interesting scripts, pause the action until the user intervenes.
With the M117 (Display Message) command, huge possibilities are created.
😉