heater: Move Thermistor and Linear to their own files in extras/

Move the Thermistor code to a new thermistor.py module.  Move the
Linear code to a new adc_temperature.py module.  This simplifies the
heater.py code.

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

1 files changed, 13 insertions, 123 deletions

diff --git a/klippy/heater.py b/klippy/heater.py
index b8f2a276..7c0def43 100644
--- a/klippy/heater.py
+++ b/klippy/heater.py
@@ -3,128 +3,17 @@
 # Copyright (C) 2016-2018  Kevin O'Connor <kevin@koconnor.net>
 #
 # This file may be distributed under the terms of the GNU GPLv3 license.
-import math, logging, threading
-
-
-######################################################################
-# Sensors
-######################################################################
-
-KELVIN_TO_CELCIUS = -273.15
-SAMPLE_TIME = 0.001
-SAMPLE_COUNT = 8
-REPORT_TIME = 0.300
-
-# Analog voltage to temperature converter for thermistors
-class Thermistor:
-    def __init__(self, config, params):
-        self.pullup = config.getfloat('pullup_resistor', 4700., above=0.)
-        ppins = config.get_printer().lookup_object('pins')
-        self.mcu_adc = ppins.setup_pin('adc', config.get('sensor_pin'))
-        self.mcu_adc.setup_adc_callback(REPORT_TIME, self.adc_callback)
-        self.temperature_callback = None
-        self.c1 = self.c2 = self.c3 = 0.
-        if 'beta' in params:
-            self.calc_coefficients_beta(params)
-        else:
-            self.calc_coefficients(params)
-    def calc_coefficients(self, params):
-        # Calculate Steinhart-Hart coefficents from temp measurements.
-        # Arrange samples as 3 linear equations and solve for c1, c2, and c3.
-        inv_t1 = 1. / (params['t1'] - KELVIN_TO_CELCIUS)
-        inv_t2 = 1. / (params['t2'] - KELVIN_TO_CELCIUS)
-        inv_t3 = 1. / (params['t3'] - KELVIN_TO_CELCIUS)
-        ln_r1 = math.log(params['r1'])
-        ln_r2 = math.log(params['r2'])
-        ln_r3 = math.log(params['r3'])
-        ln3_r1, ln3_r2, ln3_r3 = ln_r1**3, ln_r2**3, ln_r3**3
-
-        inv_t12, inv_t13 = inv_t1 - inv_t2, inv_t1 - inv_t3
-        ln_r12, ln_r13 = ln_r1 - ln_r2, ln_r1 - ln_r3
-        ln3_r12, ln3_r13 = ln3_r1 - ln3_r2, ln3_r1 - ln3_r3
-
-        self.c3 = ((inv_t12 - inv_t13 * ln_r12 / ln_r13)
-                   / (ln3_r12 - ln3_r13 * ln_r12 / ln_r13))
-        self.c2 = (inv_t12 - self.c3 * ln3_r12) / ln_r12
-        self.c1 = inv_t1 - self.c2 * ln_r1 - self.c3 * ln3_r1
-    def calc_coefficients_beta(self, params):
-        # Calculate equivalent Steinhart-Hart coefficents from beta
-        inv_t1 = 1. / (params['t1'] - KELVIN_TO_CELCIUS)
-        ln_r1 = math.log(params['r1'])
-        self.c3 = 0.
-        self.c2 = 1. / params['beta']
-        self.c1 = inv_t1 - self.c2 * ln_r1
-    def setup_minmax(self, min_temp, max_temp):
-        adc_range = [self.calc_adc(min_temp), self.calc_adc(max_temp)]
-        self.mcu_adc.setup_minmax(SAMPLE_TIME, SAMPLE_COUNT,
-                                  minval=min(adc_range), maxval=max(adc_range))
-    def setup_callback(self, temperature_callback):
-        self.temperature_callback = temperature_callback
-    def adc_callback(self, read_time, read_value):
-        # Calculate temperature from adc
-        adc = max(.00001, min(.99999, read_value))
-        r = self.pullup * adc / (1.0 - adc)
-        ln_r = math.log(r)
-        inv_t = self.c1 + self.c2 * ln_r + self.c3 * ln_r**3
-        temp = 1.0/inv_t + KELVIN_TO_CELCIUS
-        self.temperature_callback(read_time, temp)
-    def calc_adc(self, temp):
-        inv_t = 1. / (temp - KELVIN_TO_CELCIUS)
-        if self.c3:
-            # Solve for ln_r using Cardano's formula
-            y = (self.c1 - inv_t) / (2. * self.c3)
-            x = math.sqrt((self.c2 / (3. * self.c3))**3 + y**2)
-            ln_r = math.pow(x - y, 1./3.) - math.pow(x + y, 1./3.)
-        else:
-            ln_r = (inv_t - self.c1) / self.c2
-        r = math.exp(ln_r)
-        return r / (self.pullup + r)
-
-# Linear style conversion chips calibrated with two temp measurements
-class Linear:
-    def __init__(self, config, params):
-        adc_voltage = config.getfloat('adc_voltage', 5., above=0.)
-        ppins = config.get_printer().lookup_object('pins')
-        self.mcu_adc = ppins.setup_pin('adc', config.get('sensor_pin'))
-        self.mcu_adc.setup_adc_callback(REPORT_TIME, self.adc_callback)
-        self.temperature_callback = None
-        slope = (params['t2'] - params['t1']) / (params['v2'] - params['v1'])
-        self.gain = adc_voltage * slope
-        self.offset = params['t1'] - params['v1'] * slope
-    def setup_minmax(self, min_temp, max_temp):
-        adc_range = [self.calc_adc(min_temp), self.calc_adc(max_temp)]
-        self.mcu_adc.setup_minmax(SAMPLE_TIME, SAMPLE_COUNT,
-                                  minval=min(adc_range), maxval=max(adc_range))
-    def setup_callback(self, temperature_callback):
-        self.temperature_callback = temperature_callback
-    def adc_callback(self, read_time, read_value):
-        temp = read_value * self.gain + self.offset
-        self.temperature_callback(read_time, temp)
-    def calc_adc(self, temp):
-        return (temp - self.offset) / self.gain
-
-# Available sensors
-Sensors = {
-    "EPCOS 100K B57560G104F": {
-        'class': Thermistor, 't1': 25., 'r1': 100000.,
-        't2': 150., 'r2': 1641.9, 't3': 250., 'r3': 226.15 },
-    "ATC Semitec 104GT-2": {
-        'class': Thermistor, 't1': 20., 'r1': 126800.,
-        't2': 150., 'r2': 1360., 't3': 300., 'r3': 80.65 },
-    "NTC 100K beta 3950": {
-        'class': Thermistor, 't1': 25., 'r1': 100000., 'beta': 3950. },
-    "AD595": { 'class': Linear, 't1': 25., 'v1': .25, 't2': 300., 'v2': 3.022 },
-}
+import logging, threading
 
 
 ######################################################################
 # Heater
 ######################################################################
 
+KELVIN_TO_CELCIUS = -273.15
 MAX_HEAT_TIME = 5.0
 AMBIENT_TEMP = 25.
 PID_PARAM_BASE = 255.
-PWM_DELAY = REPORT_TIME + SAMPLE_TIME*SAMPLE_COUNT
 
 class error(Exception):
     pass
@@ -139,6 +28,7 @@ class Heater:
         self.max_temp = config.getfloat('max_temp', above=self.min_temp)
         self.sensor.setup_minmax(self.min_temp, self.max_temp)
         self.sensor.setup_callback(self.temperature_callback)
+        self.pwm_delay = self.sensor.get_report_time_delta()
         self.min_extrude_temp = config.getfloat(
             'min_extrude_temp', 170., minval=self.min_temp, maxval=self.max_temp)
         self.max_power = config.getfloat('max_power', 1., above=0., maxval=1.)
@@ -155,7 +45,7 @@ class Heater:
         else:
             self.mcu_pwm = ppins.setup_pin('pwm', heater_pin)
             pwm_cycle_time = config.getfloat(
-                'pwm_cycle_time', 0.100, above=0., maxval=REPORT_TIME)
+                'pwm_cycle_time', 0.100, above=0., maxval=self.pwm_delay)
             self.mcu_pwm.setup_cycle_time(pwm_cycle_time)
         self.mcu_pwm.setup_max_duration(MAX_HEAT_TIME)
         is_fileoutput = self.mcu_pwm.get_mcu().is_fileoutput()
@@ -174,7 +64,7 @@ class Heater:
             and abs(value - self.last_pwm_value) < 0.05):
             # No significant change in value - can suppress update
             return
-        pwm_time = read_time + PWM_DELAY
+        pwm_time = read_time + self.pwm_delay
         self.next_pwm_time = pwm_time + 0.75 * MAX_HEAT_TIME
         self.last_pwm_value = value
         logging.debug("%s: pwm=%.3f@%.3f (from %.3f@%.3f [%.3f])",
@@ -307,20 +197,23 @@ class PrinterHeaters:
         self.printer = printer
         self.sensors = {}
         self.heaters = {}
-    def add_sensor(self, sensor_type, params):
-        self.sensors[sensor_type] = params
+    def add_sensor(self, sensor_type, sensor_factory):
+        self.sensors[sensor_type] = sensor_factory
     def setup_heater(self, config):
         heater_name = config.get_name()
         if heater_name == 'extruder':
             heater_name = 'extruder0'
         if heater_name in self.heaters:
             raise config.error("Heater %s already registered" % (heater_name,))
+        # Setup sensor
+        self.printer.try_load_module(config, "thermistor")
+        self.printer.try_load_module(config, "adc_temperature")
         sensor_type = config.get('sensor_type')
         if sensor_type not in self.sensors:
             raise self.printer.config_error("Unknown temperature sensor '%s'" % (
                 sensor_type,))
-        params = self.sensors[sensor_type]
-        sensor = params['class'](config, params)
+        sensor = self.sensors[sensor_type](config)
+        # Create heater
         self.heaters[heater_name] = heater = Heater(config, sensor)
         return heater
     def lookup_heater(self, heater_name):
@@ -332,7 +225,4 @@ class PrinterHeaters:
         return self.heaters[heater_name]
 
 def add_printer_objects(printer, config):
-    ph = PrinterHeaters(printer, config)
-    printer.add_object('heater', ph)
-    for sensor_type, params in Sensors.items():
-        ph.add_sensor(sensor_type, params)
+    printer.add_object('heater', PrinterHeaters(printer, config))