Take advantage of __TEXT_REGION_LENGTH__ in the avr5 linker script to
preset the effective available space in the flash.
This ensures we don't overflow into the bootloader.
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