It looks we have some kind of leak when filament sensor state is not completely coherent with FINDA state.
This is yet to be discovered and fixed with some unit tests.
This solves a number of issues - if FINDA or FSensor failed,
the unload was never "complete" - filament was stuck in the selector
blocking it from normal operation.
Now, after all errors have been resolved, filament is explicitly FED
into FINDA and then RETRACTED to Pulley.
Both movable components now perform homing sequences transparently
whenever the logic layer invalidates the homingValid flag.
That reflects the fact, that the user may have moved the Idler or Selector
while trying to resolve a HW issue with un/loading filament.
Basic rules:
- Idler gets rehomed immediately and then moves into the target slot position
- Selector rehomes once it is possible - i.e. when filament load state
is AtPulley - then it immediately and spontanneously executes the homing
sequence and then returns to the desired state
Motivation:
- resolve startup issues (EEPROM says we have filament, but FINDA is not triggered)
- resolve accidental moves of Idler and/or Selector while
digging out stuck filament from the unit
D.R.racer