StoneFlower3D - how to pause a print? I've been trying to make a paste extruder and I came across StoneFlower3D. In their site, they mentioned about a feature called Infinite Printing. Please see page number 25 of this document. 

They're only using Step, Dir, Enable and GND from main controller and there's not a serial connection with the controller.

Anyone have idea about how they're doing it?
The extruder is connected to 3d printer mainboard as a stepper driver.
That said it is not using standard stepper motor output, but it is fed directly from CPU digital pins.

Please see OP reference manual. 

The extruder has theability to self-feed (load filament) - so that is the reason of kit/printer switches - see pic 1.
Then pausing a print to feed the clay tank need to be executed from printer (pause print) and then operated locally in the kit mode.



if get your comments well - pic below gives an overview how to connect it to rams - see manual for details