When calculating the advance tick interval, be sure to check for integer
overflow. Very low step rates can result in values exceeding uint16_t
causing premature LA tick delivery.
An overflow resulting in zero would also block in an infinite loop
within advance_spread().
Even though such rates are worthless in terms of compensation and often
result in 0 extra ticks as well, do not disable LA for the block (as
doing so would reset the count for short segments) and do not check for
zero in multiple paces either.
Saturate the interval instead, delaying any further tick to the next
block.
To maintain an accurate step count (which is required for correct
position recovery), any call to plan_set_position&co needs to be done
synchronously and from a halted state.
However, G92 E* is currently special-cased to skip the sync (likely to
avoid the associated performance cost), causing an incorrect E step
count and position to be set. This breaks absolute position recovery,
miscalculation of the LA factor and possibly other weird issues.
We rewrite the handling of G92 to always sync but still special-case the
frequent "G92 E0" for performance by using a free bit in the block flags.
To avoid a sync, we relay the request for reset first to the planner
which clears its internal state and then relays the request to the final
stepper isr.
Since the global feedrate can be similarly modified for moves ahead of
time, save the original feedrate in the planner as we do for
gcode_target.
This avoids having to undo feedmultiply (and machine limits!) from
"nominal_speed" as previously done.
Thanks @leptun
When starting to replay existing USB/SD commands from a recovery state,
an immediate relative move needs to compensate for a previously
interrupted move. This is almost the norm for the E axis.
Instead of saving the relative status of the move (which needs to
account for the world2machine conversion and is not always available on
a chunked move split by MBL) save directly the calculated target
position for the move in the original plan, which is easy to replay.
While handling moves in a recursive plan, such a filament check,
ensure restore_print_from_ram_and_continue unwinds the stack by
aborting early from any call that waits on the planner.
This currently only handles G1 moves, but hard-coded behavior that can
trigger recursive behavior (such as filament change) will probably have
to be checked too.
Do not store the block e_D ratio, store directly the computed
compression factor so that we can recompute the advance steps
quickly and update them in sync with the acceleration rates.
When recovering from a pause, the nozzle is often primed while
being lowered. If LA is triggered under such a move, the pressure
advance will be wasted.
Timing functions (millis, micros and delay) replaced in whole source, defined in Marlin.h.
This commit enables original implementation (SYSTEM_TIMER_2 undefined)
Verified with passed complete wizard process.
numeric accuracy and to reduce compuatitonal load. With this commit,
the numeric rounding is fixed not only for the M221 G-code
(as implemented by the preceding commit), but also for the volumetric
extrusion in general.
Removed the old FILAMENT_SENSOR code, which served the purpose
to modulate the volumetric multiplayer in real time depending
on the measured filament diameter. This feature will certainly not be
used by Prusa Research in the near future as we know of no sensor,
which would offer sufficient accuracy for a reasonable price.
