chdkActive was set to false regardless of (millis() - chdkHigh) being bigger than the CHDK_DELAY or not. So if (millis() - chdkHigh) wasn't bigger than the delay the first time, the CHDK would never be set back to LOW.
Also, don't return from the function, as there might be other stuff to do, after the CHDK check.
Positioning of string terminator to truncate checksum from the commands
M23, M28, M30, M32, M928 and M117 was off by one, causing the last
letter of the actual command to be truncated instead of just the
checksum.
In case of the SD commands this caused checksummed commands targeting
existing files to fail since the last letter of the filename was
truncated.
In case of M117 this caused the last given letter not to be displayed.
This patch fixes the off-by-one error and sets the null terminator
on the exact position of the * starting the checksum instead of the
character before that.
This is a feature to protect your printer from burn up in flames if it
has a thermistor coming off place (this happened to a friend of mine
recently and motivated me writing this feature).
The issue: If a thermistor come off, it will read a lower temperature
than actual. The system will turn the heater on forever, burning up the
filament and anything
else around.
After the temperature reaches the target for the first time, this
feature will start measuring for how long the current temperature stays
below the target minus _HYSTERESIS (set_temperature -
THERMAL_RUNAWAY_PROTECTION_HYSTERESIS).
If it stays longer than _PERIOD, it means the thermistor temperature
cannot catch up with the target, so something *may be* wrong. Then, to
be on the safe side, the system will he halt.
Bear in mind the count down will just start AFTER the first time the
thermistor temperature is over the target, so you will have no problem
if your extruder heater takes 2 minutes to hit the target on heating.
This leads to the command not being acknowledged properly
by the firmware, leading to consecutive issues in host software
waiting for an acknowledgement.
FW retraction is extended onto swap retraction invoked by 'G10 S1'.
Bookkeeping of the retract state of all extruders allows for having one
extruder fw standard retracted while another extruder is swap retracted.
An LCD menu item for the swap retract and recover length was added.
Having the non-active feeder motors powered on all the time is not
necessary. A feature to deactivate the unused feeder motors has been
implemented. The feature is enabled on default but can be switched off
in the configuration.
When using LCD_I2C_TYPE_PCF8575T (like Sainsmart I2C), the backlight
won't come on; the incorrect ifdef blocks the evocation of the backlight
functions.
