- feed to finda engages the idler so no need to do that before
- retract from finda disengages the idler, again avoid double operation
LEDs set mostly by feed to finda and retract from finda
because of the change of semantics of LoadFilament operation.
LoadFilament pushes the filament into FINDA and then retracts it back just to keep the
filament ready to be grabbed by the idler and pulley and loaded into the printer's nozzle.
So the selector is not blocked by the filament -> filament NOT loaded
I hate when the compiler doesn't check something what it normally does:
`pgm_read_byte` is more than happy with a parameter (*str), which reads
an address at a location where *str points to - which is obviously not the intent.
Load filament performs feed to FINDA and retract:
- engage idler
- feed normal to FINDA with config::feedToFinda distance until FINDA triggers
- retract normal and as soon FINDA un-triggers move back to PTFE config::cuttingEdgeToFindaMidpoint
- disengage the idler
That implied introducing another substate machine - RetractFromFinda, which does the opposite
of FeedToFinda while also checking for the FINDA switching off while retracting filament.
Still, ToolChange and CutFilament need fixing with this change
kudos to @leptun for this original and actually a very clean idea.
For the start we report "Reset finished" which in fact corresponds with the MMU state pretty closely
and plays nicely even with the protocol implementation.
And, since the default startup command is the noCommand, which always returns "Finished"
the implementation is clean and straightforward - the response to the first Q0 messages
will look like "X0 F" until a command (T, L, U ...) has been issued.