klipper-dgus/klippy/extras/adc_scaled.py

80 lines
3.5 KiB
Python

# 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)