diff options
Diffstat (limited to 'klippy/heater.py')
| -rw-r--r-- | klippy/heater.py | 136 |
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)) |