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										 |  |  | # Obtain temperature using linear interpolation of ADC values | 
					
						
							|  |  |  | # | 
					
						
							|  |  |  | # Copyright (C) 2016-2018  Kevin O'Connor <kevin@koconnor.net> | 
					
						
							|  |  |  | # | 
					
						
							|  |  |  | # This file may be distributed under the terms of the GNU GPLv3 license. | 
					
						
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										 |  |  | import logging, bisect | 
					
						
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										 |  |  | 
 | 
					
						
							|  |  |  | SAMPLE_TIME = 0.001 | 
					
						
							|  |  |  | SAMPLE_COUNT = 8 | 
					
						
							|  |  |  | REPORT_TIME = 0.300 | 
					
						
							|  |  |  | 
 | 
					
						
							|  |  |  | # Linear style conversion chips calibrated with two temp measurements | 
					
						
							|  |  |  | class Linear: | 
					
						
							|  |  |  |     def __init__(self, config, params): | 
					
						
							|  |  |  |         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 | 
					
						
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										 |  |  |         self.adc_samples = [] | 
					
						
							|  |  |  |         self.slope_samples = [] | 
					
						
							|  |  |  |         self.calc_coefficients(config, params) | 
					
						
							|  |  |  |     def calc_coefficients(self, config, params): | 
					
						
							|  |  |  |         adc_voltage = config.getfloat('adc_voltage', 5., above=0.) | 
					
						
							|  |  |  |         last_volt = last_temp = None | 
					
						
							|  |  |  |         for volt, temp in sorted([(v, t) for t, v in params]): | 
					
						
							|  |  |  |             adc = volt / adc_voltage | 
					
						
							|  |  |  |             if adc < 0. or adc > 1.: | 
					
						
							|  |  |  |                 logging.warn("Ignoring adc sample %.3f/%.3f in heater %s", | 
					
						
							|  |  |  |                              temp, volt, config.get_name()) | 
					
						
							|  |  |  |                 continue | 
					
						
							|  |  |  |             if last_volt is None: | 
					
						
							|  |  |  |                 last_volt = volt | 
					
						
							|  |  |  |                 last_temp = temp | 
					
						
							|  |  |  |                 continue | 
					
						
							|  |  |  |             if volt <= last_volt: | 
					
						
							|  |  |  |                 raise config.error("adc_temperature duplicate voltage") | 
					
						
							|  |  |  |             slope = (temp - last_temp) / (volt - last_volt) | 
					
						
							|  |  |  |             gain = adc_voltage * slope | 
					
						
							|  |  |  |             offset = last_temp - last_volt * slope | 
					
						
							|  |  |  |             if self.slope_samples and self.slope_samples[-1] == (gain, offset): | 
					
						
							|  |  |  |                 continue | 
					
						
							|  |  |  |             last_temp = temp | 
					
						
							|  |  |  |             last_volt = volt | 
					
						
							|  |  |  |             self.adc_samples.append(adc) | 
					
						
							|  |  |  |             self.slope_samples.append((gain, offset)) | 
					
						
							|  |  |  |         if not self.adc_samples: | 
					
						
							|  |  |  |             raise config.error( | 
					
						
							|  |  |  |                 "adc_temperature needs two volt and temperature measurements") | 
					
						
							|  |  |  |         self.adc_samples[-1] = 1. | 
					
						
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										 |  |  |     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 get_report_time_delta(self): | 
					
						
							|  |  |  |         return REPORT_TIME | 
					
						
							|  |  |  |     def adc_callback(self, read_time, read_value): | 
					
						
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										 |  |  |         pos = bisect.bisect(self.adc_samples, read_value) | 
					
						
							|  |  |  |         gain, offset = self.slope_samples[pos] | 
					
						
							|  |  |  |         temp = read_value * gain + offset | 
					
						
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										 |  |  |         self.temperature_callback(read_time + SAMPLE_COUNT * SAMPLE_TIME, temp) | 
					
						
							|  |  |  |     def calc_adc(self, temp): | 
					
						
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										 |  |  |         temps = [adc * gain + offset for adc, (gain, offset) in zip( | 
					
						
							|  |  |  |             self.adc_samples, self.slope_samples)] | 
					
						
							|  |  |  |         if temps[0] < temps[-1]: | 
					
						
							|  |  |  |             pos = min([i for i in range(len(temps)) if temps[i] >= temp] | 
					
						
							|  |  |  |                       + [len(temps) - 1]) | 
					
						
							|  |  |  |         else: | 
					
						
							|  |  |  |             pos = min([i for i in range(len(temps)) if temps[i] <= temp] | 
					
						
							|  |  |  |                       + [len(temps) - 1]) | 
					
						
							|  |  |  |         gain, offset = self.slope_samples[pos] | 
					
						
							|  |  |  |         return (temp - offset) / gain | 
					
						
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										 |  |  | AD595 = [ | 
					
						
							|  |  |  |     (0., .0027), (10., .101), (20., .200), (25., .250), (30., .300), (40., .401), | 
					
						
							|  |  |  |     (50., .503), (60., .605), (80., .810), (100., 1.015), (120., 1.219), | 
					
						
							|  |  |  |     (140., 1.420), (160., 1.620), (180., 1.817), (200., 2.015), (220., 2.213), | 
					
						
							|  |  |  |     (240., 2.413), (260., 2.614), (280., 2.817), (300., 3.022), (320., 3.227), | 
					
						
							|  |  |  |     (340., 3.434), (360., 3.641), (380., 3.849), (400., 4.057), (420., 4.266), | 
					
						
							|  |  |  |     (440., 4.476), (460., 4.686), (480., 4.896) | 
					
						
							|  |  |  | ] | 
					
						
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										 |  |  | 
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										 |  |  | PT100 = [ | 
					
						
							|  |  |  |     (0, 0.00), (1, 1.11), (10, 1.15), (20, 1.20), (30, 1.24), (40, 1.28), | 
					
						
							|  |  |  |     (50, 1.32), (60, 1.36), (70, 1.40), (80, 1.44), (90, 1.48), (100, 1.52), | 
					
						
							|  |  |  |     (110, 1.56), (120, 1.61), (130, 1.65), (140, 1.68), (150, 1.72), (160, 1.76), | 
					
						
							|  |  |  |     (170, 1.80), (180, 1.84), (190, 1.88), (200, 1.92), (210, 1.96), (220, 2.00), | 
					
						
							|  |  |  |     (230, 2.04), (240, 2.07), (250, 2.11), (260, 2.15), (270, 2.18), (280, 2.22), | 
					
						
							|  |  |  |     (290, 2.26), (300, 2.29), (310, 2.33), (320, 2.37), (330, 2.41), (340, 2.44), | 
					
						
							|  |  |  |     (350, 2.48), (360, 2.51), (370, 2.55), (380, 2.58), (390, 2.62), (400, 2.66), | 
					
						
							|  |  |  |     (500, 3.00), (600, 3.33), (700, 3.63), (800, 3.93), (900, 4.21), | 
					
						
							|  |  |  |     (1000, 4.48), (1100, 4.73) | 
					
						
							|  |  |  | ] | 
					
						
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										 |  |  | def load_config(config): | 
					
						
							|  |  |  |     # Register default sensors | 
					
						
							|  |  |  |     pheater = config.get_printer().lookup_object("heater") | 
					
						
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										 |  |  |     for sensor_type, params in [("AD595", AD595), ("PT100 INA826", PT100)]: | 
					
						
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										 |  |  |         func = (lambda config, params=params: Linear(config, params)) | 
					
						
							|  |  |  |         pheater.add_sensor(sensor_type, func) |