heater: Add PrinterHeaters class that stores all sensors and heaters

Add a PrinterHeaters class that can stores references to available
temperature sensors and stores references to instantiated heaters.

Add a extras/heater_bed.py file and delay instantiation of the
heater_bed object.  This allows the heater.py module to be imported
earlier during the setup phase, and allows the PrinterHeaters class to
be available for registering sensors and heaters.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

klippy/extras/heater_bed.py

@@ -0,0 +1,8 @@
+# Support for a heated bed
+#
+# Copyright (C) 2018  Kevin O'Connor <kevin@koconnor.net>
+#
+# This file may be distributed under the terms of the GNU GPLv3 license.
+
+def load_config(config):
+    return config.get_printer().lookup_object('heater').setup_heater(config)

klippy/extras/heater_fan.py

@@ -3,7 +3,7 @@
 # Copyright (C) 2016-2018  Kevin O'Connor <kevin@koconnor.net>
 #
 # This file may be distributed under the terms of the GNU GPLv3 license.
-import fan, extruder
+import fan
 
 PIN_MIN_TIME = 0.100
 
@@ -20,8 +20,8 @@ class PrinterHeaterFan:
         self.fan.mcu_fan.setup_start_value(0., max_power)
     def printer_state(self, state):
         if state == 'ready':
-            self.heater = extruder.get_printer_heater(
-                self.printer, self.heater_name)
+            pheater = self.printer.lookup_object('heater')
+            self.heater = pheater.lookup_heater(self.heater_name)
             reactor = self.printer.get_reactor()
             reactor.register_timer(self.callback, reactor.NOW)
     def callback(self, eventtime):

klippy/extras/pid_calibrate.py

@@ -4,7 +4,7 @@
 #
 # This file may be distributed under the terms of the GNU GPLv3 license.
 import math, logging
-import extruder, heater
+import heater
 
 class PIDCalibrate:
     def __init__(self, config):
@@ -18,8 +18,9 @@ class PIDCalibrate:
         heater_name = self.gcode.get_str('HEATER', params)
         target = self.gcode.get_float('TARGET', params)
         write_file = self.gcode.get_int('WRITE_FILE', params, 0)
+        pheater = self.printer.lookup_object('heater')
         try:
-            heater = extruder.get_printer_heater(self.printer, heater_name)
+            heater = pheater.lookup_heater(heater_name)
         except self.printer.config_error as e:
             raise self.gcode.error(str(e))
         print_time = self.printer.lookup_object('toolhead').get_last_move_time()

klippy/extras/verify_heater.py

@@ -4,7 +4,6 @@
 #
 # This file may be distributed under the terms of the GNU GPLv3 license.
 import logging
-import extruder
 
 HINT_THERMAL = """
 See the 'verify_heater' section in config/example-extras.cfg
@@ -29,8 +28,8 @@ class HeaterCheck:
         self.fault_systime = self.printer.get_reactor().NEVER
     def printer_state(self, state):
         if state == 'connect':
-            self.heater = extruder.get_printer_heater(
-                self.printer, self.heater_name)
+            pheater = self.printer.lookup_object('heater')
+            self.heater = pheater.lookup_heater(self.heater_name)
             logging.info("Starting heater checks for %s", self.heater_name)
             reactor = self.printer.get_reactor()
             reactor.register_timer(self.check_event, reactor.NOW)