fastio relies on macros for pin definitions, so we cannot use the const
declaration in Sd2PinMap or the arduino's definition.
Declare SDA/SCL_PIN into pins.h based on the current MCU, which is
identical in all our variants.
Remove the conflicting/unused declaration in Sd2PinMap.
- Start saving instructions as the whole PR was >1KB long.
- It turned out the compiler was unable to understand the core skipping
cycle and an ASM version had to be used.
- Add seekSet aware of the G-code filter
This is an extension/optimization of PR #2956.
It uses the cached 512B block buffer to avoid heavy-weight read() in SdBaseFile.
Even though this principle allowed the AVR to skip ~600KB of data within ~5 seconds,
the impact on code base is huge, especially into well proven and long-term stable
parts like reading a file from the SD card.
The sole purpose of this PR is to show/verify the possibility of the AVR CPU
in relation to adding thumbnails into MK3 G-codes.
Moreover, this PR shall not be merged unless the missing/commented features
are restored - especially file seeking and M84 search.
PFW-1175
If there are large blocks of comments in the G-code,
the printer may get shot down by its own watchdog.
Watchdog is generally set to 4s and updated only
in manage_heaters (and some other spots in some specific cases).
So far, the code reading the file and feeding it into Marlin
cycles indefinitely until it finds valid G-code lines and fills up the
command queue.
If the block is large enough, the printer cannot read it completely
within those 4s.
A simple workaround - bail out after some consecutive empty/comment
lines to enable other parts of code do their job (especially
manage_heaters).
Tested on MK404, previous FW fails with 600KB of comment lines at the
beginning, this patch survives. The printer even draws some update
on its status screen before starting a real print.
Introduce new macros TMC2130_MINIMUM_DELAY/STEPPER_MINIMUM_DELAY for
blocking pauses.
If MINIMUM_PULSE has defined to be zero, avoid the delay call entirely.
Farmers request having the Change filament menu item always visible in
the main menu and located after the Live Adjust Z (which disappears
after the first few printed layers).
