It is a realtime control over the head position via the LCD menu system that works _while_ printing.
Using it, one can e.g. tune the z-position in realtime, while printing the first layer.
Also, lost steps can be manually added/removed, but thats not the prime feature.
Stuff is placed into the Tune->Babystep *
It is not possible to have realtime control via gcode sending due to the buffering, so I did not include a gcode yet. However, it could be added, but it movements will not be realtime then.
Historically, a very similar thing was implemented for the "Kaamermaker" project, while Joris was babysitting his offspring, hence the name.
say goodby to fuddling around with the z-axis.
and the mechanism so that if an endstop is hit it the ISR, the steps_to_be_taken are stored, and some current_block data that will be deleted in the next move
If the normal loop() then finds such an event, the position is calculated (floats would have taken too long in the ISR) A serial message is generated.