palette2: Add ping variation + ping status reports (#4114)

Signed-off-by: Clifford Roche <clifford.roche@gmail.com>

docs/Command_Templates.md

@@ -313,6 +313,12 @@ The following are common printer attributes:
 - `printer.system_stats.sysload`, `printer.system_stats.cputime`,
   `printer.system_stats.memavail`: Information on the host operating
   system and process load.
+- `printer.palette2.ping`: Amount of the last reported Palette 2 ping
+  in percent.
+- `printer.palette2.remaining_load_length`: When starting a Palette 2
+  print, this will be the amount of filament to load into the extruder.
+- `printer.palette2.is_splicing`: True when the Palette 2 is splicing
+  filament.
 
 The above list is subject to change - if using an attribute be sure to
 review the [Config Changes document](Config_Changes.md) when upgrading

docs/Config_Reference.md

@@ -3903,12 +3903,14 @@ for your print to begin.
 [palette2]
 serial:
 #   The serial port to connect to the Palette 2.
-#baud: 250000
-#   The baud rate to use. The default is 250000.
+#baud: 115200
+#   The baud rate to use. The default is 115200.
 #feedrate_splice: 0.8
 #   The feedrate to use when splicing, default is 0.8
 #feedrate_normal: 1.0
 #   The feedrate to use after splicing, default is 1.0
 #auto_load_speed: 2
 #   Extrude feedrate when autoloading, default is 2 (mm/s)
+#auto_cancel_variation: 0.1
+#   Auto cancel print when ping varation is above this threshold
 ```