fan_generic: Add support for named fans and gcode to control them (#3054)

Signed-off-by: Pontus Borg <liquidpontus@yahoo.se>

config/example-extras.cfg

@@ -1224,6 +1224,12 @@
 #   given id. The default is to not report the temperature via M105.
 
 
+# Manually controlled fan (one may define any number of sections with a
+# "fan_generic" prefix). The speed of a manually controlled fan is set with the
+# SET_FAN_SPEED gcode command.
+#[fan_generic extruder_partfan]
+#   Options are the same as for the [fan] section
+
 ######################################################################
 # Additional servos, LEDs, buttons, and other pins
 ######################################################################

docs/G-Codes.md

@@ -244,6 +244,13 @@ The following command is available when an "output_pin" config section
 is enabled:
 - `SET_PIN PIN=config_name VALUE=<value>`
 
+## Manually Controlled Fans Commands
+
+The following command is available when a "fan_generic" config section
+is enabled:
+- `SET_FAN_SPEED FAN=config_name SPEED=<speed>` This command sets
+  the speed of a fan. <speed> must be between 0.0 and 1.0.
+
 ## Neopixel and Dotstar Commands
 
 The following command is available when "neopixel" or "dotstar" config

klippy/extras/fan_generic.py

@@ -0,0 +1,28 @@
+# Support fans that are controlled by gcode
+#
+# Copyright (C) 2016-2020  Kevin O'Connor <kevin@koconnor.net>
+#
+# This file may be distributed under the terms of the GNU GPLv3 license.
+from . import fan
+
+class PrinterFanGeneric:
+    cmd_SET_FAN_SPEED_help = "Sets the speed of a fan"
+    def __init__(self, config):
+        self.printer = config.get_printer()
+        self.fan = fan.Fan(config, default_shutdown_speed=0.)
+        self.fan_name = config.get_name().split()[-1]
+
+        gcode = self.printer.lookup_object("gcode")
+        gcode.register_mux_command("SET_FAN_SPEED", "FAN",
+                                   self.fan_name,
+                                   self.cmd_SET_FAN_SPEED,
+                                   desc=self.cmd_SET_FAN_SPEED_help)
+
+    def get_status(self, eventtime):
+        return self.fan.get_status(eventtime)
+    def cmd_SET_FAN_SPEED(self, gcmd):
+        speed = gcmd.get_float('SPEED', 0.)
+        self.fan.set_speed_from_command(speed)
+
+def load_config_prefix(config):
+    return PrinterFanGeneric(config)