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>

1 files changed, 3 insertions, 3 deletions

diff --git a/klippy/klippy.py b/klippy/klippy.py
index 77ab3cc0..9532b911 100644
--- a/klippy/klippy.py
+++ b/klippy/klippy.py
@@ -7,7 +7,7 @@
 import sys, os, optparse, logging, time, threading
 import collections, ConfigParser, importlib
 import util, reactor, queuelogger, msgproto
-import gcode, pins, mcu, toolhead, extruder, heater
+import gcode, pins, heater, mcu, toolhead, extruder
 
 message_ready = "Printer is ready"
 
@@ -204,11 +204,11 @@ class Printer:
             ConfigLogger(fileconfig, self.bglogger)
         # Create printer components
         config = ConfigWrapper(self, fileconfig, 'printer')
-        for m in [pins, mcu]:
+        for m in [pins, heater, mcu]:
             m.add_printer_objects(self, config)
         for section in fileconfig.sections():
             self.try_load_module(config, section)
-        for m in [toolhead, extruder, heater]:
+        for m in [toolhead, extruder]:
             m.add_printer_objects(self, config)
         # Validate that there are no undefined parameters in the config file
         valid_sections = { s: 1 for s, o in self.all_config_options }