If FSENSOR_DIDNT_SWITCH_ON was caused by misaligned Idler, rehoming it may fix the issue when auto retrying -> no user intervention.
So first invalidate homing flags as the user may have moved the Idler or Selector accidentally.
Beware: we may run into issues when FINDA or FSensor do not work correctly. Selector may rely on the presumed filament position and actually cut it accidentally when trying to rehome.
It is yet to be seen if something like this can actually happen.
MMU-191
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.
Originally, only FeedingToBondtech was reported to the printer.
With PR#173 we have this operation separated into a fast and a slow stage (for MK3S with the chimney).
It looks like the printer could benefit from knowing if the MMU is still pushing fast
or when it entered the slow stage (to prevent ramming hard the Bondtech gears)
Along with this new state being reported, we also introduce a new ErrorCode::FSENSOR_TOO_EARLY
which basically means that the fsensor triggered in the fast feeding stage.
Besides Unload Filament, which only operates on active slot, all other
top level state machines check the validity of the command's parameter.
If the parameter is out of range for available slots, they return
ErrorCode::INVALID_TOOL now.
D.R.racer
Guðni Már Gilbert
3d-gussner