80 lines
3.5 KiB
Python
80 lines
3.5 KiB
Python
# Support for scaling ADC values based on measured VREF and VSSA
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#
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# Copyright (C) 2020 Kevin O'Connor <kevin@koconnor.net>
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#
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# This file may be distributed under the terms of the GNU GPLv3 license.
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SAMPLE_TIME = 0.001
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SAMPLE_COUNT = 8
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REPORT_TIME = 0.300
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RANGE_CHECK_COUNT = 4
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class MCU_scaled_adc:
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def __init__(self, main, pin_params):
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self._main = main
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self._last_state = (0., 0.)
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self._mcu_adc = main.mcu.setup_pin('adc', pin_params)
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query_adc = main.printer.lookup_object('query_adc')
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qname = main.name + ":" + pin_params['pin']
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query_adc.register_adc(qname, self._mcu_adc)
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self._callback = None
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self.setup_minmax = self._mcu_adc.setup_minmax
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self.get_mcu = self._mcu_adc.get_mcu
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def _handle_callback(self, read_time, read_value):
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max_adc = self._main.last_vref[1]
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min_adc = self._main.last_vssa[1]
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scaled_val = (read_value - min_adc) / (max_adc - min_adc)
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self._last_state = (scaled_val, read_time)
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self._callback(read_time, scaled_val)
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def setup_adc_callback(self, report_time, callback):
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self._callback = callback
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self._mcu_adc.setup_adc_callback(report_time, self._handle_callback)
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def get_last_value(self):
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return self._last_state
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class PrinterADCScaled:
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def __init__(self, config):
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self.printer = config.get_printer()
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self.name = config.get_name().split()[1]
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self.last_vref = (0., 0.)
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self.last_vssa = (0., 0.)
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# Configure vref and vssa pins
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self.mcu_vref = self._config_pin(config, 'vref', self.vref_callback)
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self.mcu_vssa = self._config_pin(config, 'vssa', self.vssa_callback)
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smooth_time = config.getfloat('smooth_time', 2., above=0.)
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self.inv_smooth_time = 1. / smooth_time
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self.mcu = self.mcu_vref.get_mcu()
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if self.mcu is not self.mcu_vssa.get_mcu():
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raise config.error("vref and vssa must be on same mcu")
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# Register setup_pin
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ppins = self.printer.lookup_object('pins')
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ppins.register_chip(self.name, self)
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def _config_pin(self, config, name, callback):
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pin_name = config.get(name + '_pin')
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ppins = self.printer.lookup_object('pins')
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mcu_adc = ppins.setup_pin('adc', pin_name)
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mcu_adc.setup_adc_callback(REPORT_TIME, callback)
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mcu_adc.setup_minmax(SAMPLE_TIME, SAMPLE_COUNT, minval=0., maxval=1.,
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range_check_count=RANGE_CHECK_COUNT)
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query_adc = config.get_printer().load_object(config, 'query_adc')
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query_adc.register_adc(self.name + ":" + name, mcu_adc)
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return mcu_adc
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def setup_pin(self, pin_type, pin_params):
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if pin_type != 'adc':
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raise self.printer.config_error("adc_scaled only supports adc pins")
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return MCU_scaled_adc(self, pin_params)
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def calc_smooth(self, read_time, read_value, last):
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last_time, last_value = last
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time_diff = read_time - last_time
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value_diff = read_value - last_value
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adj_time = min(time_diff * self.inv_smooth_time, 1.)
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smoothed_value = last_value + value_diff * adj_time
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return (read_time, smoothed_value)
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def vref_callback(self, read_time, read_value):
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self.last_vref = self.calc_smooth(read_time, read_value, self.last_vref)
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def vssa_callback(self, read_time, read_value):
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self.last_vssa = self.calc_smooth(read_time, read_value, self.last_vssa)
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def load_config_prefix(config):
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return PrinterADCScaled(config)
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