diff options
Diffstat (limited to 'klippy')
| -rw-r--r-- | klippy/extras/adc_scaled.py | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/klippy/extras/adc_scaled.py b/klippy/extras/adc_scaled.py new file mode 100644 index 00000000..c2d2cb87 --- /dev/null +++ b/klippy/extras/adc_scaled.py @@ -0,0 +1,79 @@ +# Support for scaling ADC values based on measured VREF and VSSA +# +# Copyright (C) 2020 Kevin O'Connor <kevin@koconnor.net> +# +# This file may be distributed under the terms of the GNU GPLv3 license. + +SAMPLE_TIME = 0.001 +SAMPLE_COUNT = 8 +REPORT_TIME = 0.300 +RANGE_CHECK_COUNT = 4 + +class MCU_scaled_adc: + def __init__(self, main, pin_params): + self._main = main + self._last_state = (0., 0.) + self._mcu_adc = main.mcu.setup_pin('adc', pin_params) + query_adc = main.printer.lookup_object('query_adc') + qname = main.name + ":" + pin_params['pin'] + query_adc.register_adc(qname, self._mcu_adc) + self._callback = None + self.setup_minmax = self._mcu_adc.setup_minmax + self.get_mcu = self._mcu_adc.get_mcu + def _handle_callback(self, read_time, read_value): + max_adc = self._main.last_vref[1] + min_adc = self._main.last_vssa[1] + scaled_val = (read_value - min_adc) / (max_adc - min_adc) + self._last_state = (scaled_val, read_time) + self._callback(read_time, scaled_val) + def setup_adc_callback(self, report_time, callback): + self._callback = callback + self._mcu_adc.setup_adc_callback(report_time, self._handle_callback) + def get_last_value(self): + return self._last_state + +class PrinterADCScaled: + def __init__(self, config): + self.printer = config.get_printer() + self.name = config.get_name().split()[1] + self.last_vref = (0., 0.) + self.last_vssa = (0., 0.) + # Configure vref and vssa pins + self.mcu_vref = self._config_pin(config, 'vref', self.vref_callback) + self.mcu_vssa = self._config_pin(config, 'vssa', self.vssa_callback) + smooth_time = config.getfloat('smooth_time', 2., above=0.) + self.inv_smooth_time = 1. / smooth_time + self.mcu = self.mcu_vref.get_mcu() + if self.mcu is not self.mcu_vssa.get_mcu(): + raise config.error("vref and vssa must be on same mcu") + # Register setup_pin + ppins = self.printer.lookup_object('pins') + ppins.register_chip(self.name, self) + def _config_pin(self, config, name, callback): + pin_name = config.get(name + '_pin') + ppins = self.printer.lookup_object('pins') + mcu_adc = ppins.setup_pin('adc', pin_name) + mcu_adc.setup_adc_callback(REPORT_TIME, callback) + mcu_adc.setup_minmax(SAMPLE_TIME, SAMPLE_COUNT, minval=0., maxval=1., + range_check_count=RANGE_CHECK_COUNT) + query_adc = config.get_printer().load_object(config, 'query_adc') + query_adc.register_adc(self.name + ":" + name, mcu_adc) + return mcu_adc + def setup_pin(self, pin_type, pin_params): + if pin_type != 'adc': + raise self.printer.config_error("adc_scaled only supports adc pins") + return MCU_scaled_adc(self, pin_params) + def calc_smooth(self, read_time, read_value, last): + last_time, last_value = last + time_diff = read_time - last_time + value_diff = read_value - last_value + adj_time = min(time_diff * self.inv_smooth_time, 1.) + smoothed_value = last_value + value_diff * adj_time + return (read_time, smoothed_value) + def vref_callback(self, read_time, read_value): + self.last_vref = self.calc_smooth(read_time, read_value, self.last_vref) + def vssa_callback(self, read_time, read_value): + self.last_vssa = self.calc_smooth(read_time, read_value, self.last_vssa) + +def load_config_prefix(config): + return PrinterADCScaled(config) |