Fixes the motion stutters generally happening as more than a single
axis are active and one completes in the middle of the motion.
Do not generate a spourious interval as one axis exits the queue. This
short interval didn't account for the minimal stepping quantum,
potentially causing a timer overflow.
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.
Slower loading speed is necessary for precise detection
of filament sensor trigger and starting rotation of the E-motor.
Experimentally it turned out speeds above 80mm/s tend to cause timing issues
(sometimes one can hear a crack as MMU' or the printer's drive gears
slip while pushing the filament).
Such a timing issue then causes blobs in purge towers.
On the other hand - 80mm/s for the fast part of filament load
seems not only absolutely reliable, but also very quiet.
120mm/s for unload is much louder (we may slow it down later)
Solves an interesting tiny issue introduced in the previous commits.
When we start with the filament in selector, the corresponding LED
is set to ON. However, all of the logic state machines only operated
on the LED pair of the active slot -> the starting LED may have been
left ON in some edge cases.
Now, this is resolved by clearing all other LEDs except for the active
slot where appropriate.
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
Previously it looked like only the active block has been discarded
which worked most of the time, since we only planned single moves.
But with introduction of PlanLongMove in one of the last commits
this is not true anymore.
we may discuss when to check for the FSensor state and why,
but this approach seemed to me like the least invasive method
of just checking the fsensor state and reporting an error in case
it didn't switch off.
In AVR __builtin_abs() breaks for non-base types.
Provide a generic function and use an overload when it is safe to use
instead.
This fixes the underlying step count calculation in PlanMove, thus
removing the need for the PlanLongMove work-around.
- fix homing procedure for Idler and Selector
(homing now ends with a move to the Parking position)
- fix unit tests' startup conditions with regard to necessary
homing of Idler and Selector
TODO: still test_cut_filament fails for minor reasons
That includes:
- introduce pulley slow feedrate and fsensor-to-nozzle distance
in config necessary for slowly feeding the filament from fsensor into the nozzle.
(the constant is subject to extraction into some other config as it has to be used in the printer as well).
- update FeedToBondtech accordingly to perform a gentle push into the nozzle
after fsensor detects the filament + update its unit tests.
- slight cleanup of LoadFilament + fix its unit tests
- add FeedingToNozzle progress code, as it might be interesting
to inform the printer about this task in the future
- revert non-clean changes from RetractFromFinda - it should not disengage the idler
- revert incorrect + fix ToolChange
- clean-up UnloadFilament
Should also hopefully fix the random behavior of the DIR pins. When I was testing a really slow timing, the steppers seemed to want to not go in the right direction. That was fixed with the critical section. The 1us delay might be overkill, but I'm not the one that added a 100nF capacitor on the LATCH line (basically chip select). This might be part of the randomness that happened and why some board behaved better than others (stronger GPIO outputs)
- 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
Yuri D'Elia
D.R.racer
Alex Voinea
3d-gussner