194 lines
9.5 KiB
Python
194 lines
9.5 KiB
Python
# Printer stepper support
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#
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# Copyright (C) 2016,2017 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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import math, logging
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import homing, pins
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# Code storing the definitions for a stepper motor
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class PrinterStepper:
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def __init__(self, printer, config):
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self.name = config.section
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if self.name.startswith('stepper_'):
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self.name = self.name[8:]
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self.need_motor_enable = True
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# Stepper definition
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self.mcu_stepper = pins.setup_pin(
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printer, 'stepper', config.get('step_pin'))
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dir_pin_params = pins.get_printer_pins(printer).parse_pin_desc(
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config.get('dir_pin'), can_invert=True)
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self.mcu_stepper.setup_dir_pin(dir_pin_params)
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self.step_dist = config.getfloat('step_distance', above=0.)
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self.mcu_stepper.setup_step_distance(self.step_dist)
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self.step_const = self.mcu_stepper.step_const
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self.step_delta = self.mcu_stepper.step_delta
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# Enable pin
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enable_pin = config.get('enable_pin', None)
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self.mcu_enable = None
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if enable_pin is not None:
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self.mcu_enable = pins.setup_pin(printer, 'digital_out', enable_pin)
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self.mcu_enable.setup_max_duration(0.)
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def _dist_to_time(self, dist, start_velocity, accel):
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# Calculate the time it takes to travel a distance with constant accel
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time_offset = start_velocity / accel
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return math.sqrt(2. * dist / accel + time_offset**2) - time_offset
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def set_max_jerk(self, max_halt_velocity, max_accel):
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# Calculate the firmware's maximum halt interval time
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last_step_time = self._dist_to_time(
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self.step_dist, max_halt_velocity, max_accel)
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second_last_step_time = self._dist_to_time(
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2. * self.step_dist, max_halt_velocity, max_accel)
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min_stop_interval = second_last_step_time - last_step_time
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self.mcu_stepper.setup_min_stop_interval(min_stop_interval)
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def set_position(self, pos):
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self.mcu_stepper.set_position(pos)
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def motor_enable(self, print_time, enable=0):
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if (self.mcu_enable is not None
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and self.need_motor_enable != (not enable)):
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self.mcu_enable.set_digital(print_time, enable)
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self.need_motor_enable = not enable
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# Support for stepper controlled linear axis with an endstop
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class PrinterHomingStepper(PrinterStepper):
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def __init__(self, printer, config, default_position=None):
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PrinterStepper.__init__(self, printer, config)
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# Endstop and its position
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self.mcu_endstop = pins.setup_pin(
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printer, 'endstop', config.get('endstop_pin'))
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self.mcu_endstop.add_stepper(self.mcu_stepper)
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if default_position is None:
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self.position_endstop = config.getfloat('position_endstop')
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else:
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self.position_endstop = config.getfloat(
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'position_endstop', default_position)
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# Axis range
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self.position_min = config.getfloat('position_min', 0.)
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self.position_max = config.getfloat(
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'position_max', 0., above=self.position_min)
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# Homing mechanics
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self.homing_speed = config.getfloat('homing_speed', 5.0, above=0.)
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self.homing_retract_dist = config.getfloat(
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'homing_retract_dist', 5., above=0.)
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self.homing_positive_dir = config.getboolean('homing_positive_dir', None)
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if self.homing_positive_dir is None:
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axis_len = self.position_max - self.position_min
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if self.position_endstop <= self.position_min + axis_len / 4.:
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self.homing_positive_dir = False
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elif self.position_endstop >= self.position_max - axis_len / 4.:
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self.homing_positive_dir = True
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else:
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raise config.error(
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"Unable to infer homing_positive_dir in section '%s'" % (
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config.section,))
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# Endstop stepper phase position tracking
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self.homing_stepper_phases = config.getint(
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'homing_stepper_phases', None, minval=0)
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endstop_accuracy = config.getfloat(
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'homing_endstop_accuracy', None, above=0.)
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self.homing_endstop_accuracy = self.homing_endstop_phase = None
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if self.homing_stepper_phases:
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self.homing_endstop_phase = config.getint(
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'homing_endstop_phase', None, minval=0
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, maxval=self.homing_stepper_phases-1)
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if (self.homing_endstop_phase is not None
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and config.getboolean('homing_endstop_align_zero', False)):
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# Adjust the endstop position so 0.0 is always at a full step
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micro_steps = self.homing_stepper_phases // 4
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phase_offset = (
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((self.homing_endstop_phase + micro_steps // 2) % micro_steps)
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- micro_steps // 2) * self.step_dist
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full_step = micro_steps * self.step_dist
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es_pos = (int(self.position_endstop / full_step + .5) * full_step
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+ phase_offset)
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if es_pos != self.position_endstop:
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logging.info("Changing %s endstop position to %.3f"
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" (from %.3f)", self.name, es_pos,
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self.position_endstop)
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self.position_endstop = es_pos
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if endstop_accuracy is None:
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self.homing_endstop_accuracy = self.homing_stepper_phases//2 - 1
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elif self.homing_endstop_phase is not None:
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self.homing_endstop_accuracy = int(math.ceil(
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endstop_accuracy * .5 / self.step_dist))
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else:
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self.homing_endstop_accuracy = int(math.ceil(
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endstop_accuracy / self.step_dist))
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if self.homing_endstop_accuracy >= self.homing_stepper_phases // 2:
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logging.info("Endstop for %s is not accurate enough for stepper"
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" phase adjustment", name)
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self.homing_stepper_phases = None
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if self.mcu_endstop.get_mcu().is_fileoutput():
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self.homing_endstop_accuracy = self.homing_stepper_phases
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def get_endstops(self):
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return [(self.mcu_endstop, self.name)]
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def get_homing_speed(self):
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# Round the configured homing speed so that it is an even
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# number of ticks per step.
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adjusted_freq = self.mcu_stepper.get_mcu().get_adjusted_freq()
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dist_ticks = adjusted_freq * self.step_dist
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ticks_per_step = round(dist_ticks / self.homing_speed)
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return dist_ticks / ticks_per_step
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def get_homed_offset(self):
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if not self.homing_stepper_phases or self.need_motor_enable:
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return 0.
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pos = self.mcu_stepper.get_mcu_position()
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pos %= self.homing_stepper_phases
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if self.homing_endstop_phase is None:
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logging.info("Setting %s endstop phase to %d", self.name, pos)
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self.homing_endstop_phase = pos
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return 0.
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delta = (pos - self.homing_endstop_phase) % self.homing_stepper_phases
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if delta >= self.homing_stepper_phases - self.homing_endstop_accuracy:
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delta -= self.homing_stepper_phases
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elif delta > self.homing_endstop_accuracy:
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raise homing.EndstopError(
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"Endstop %s incorrect phase (got %d vs %d)" % (
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self.name, pos, self.homing_endstop_phase))
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return delta * self.step_dist
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# Wrapper for dual stepper motor support
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class PrinterMultiStepper(PrinterHomingStepper):
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def __init__(self, printer, config):
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PrinterHomingStepper.__init__(self, printer, config)
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self.endstops = PrinterHomingStepper.get_endstops(self)
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self.extras = []
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self.all_step_const = [self.step_const]
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for i in range(1, 99):
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if not config.has_section(config.section + str(i)):
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break
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extraconfig = config.getsection(config.section + str(i))
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extra = PrinterStepper(printer, extraconfig)
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self.extras.append(extra)
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self.all_step_const.append(extra.step_const)
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extraendstop = extraconfig.get('endstop_pin', None)
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if extraendstop is not None:
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mcu_endstop = pins.setup_pin(printer, 'endstop', extraendstop)
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mcu_endstop.add_stepper(extra.mcu_stepper)
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self.endstops.append((mcu_endstop, extra.name))
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else:
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self.mcu_endstop.add_stepper(extra.mcu_stepper)
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self.step_const = self.step_multi_const
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def step_multi_const(self, print_time, start_pos, dist, start_v, accel):
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for step_const in self.all_step_const:
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step_const(print_time, start_pos, dist, start_v, accel)
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def set_max_jerk(self, max_halt_velocity, max_accel):
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PrinterHomingStepper.set_max_jerk(self, max_halt_velocity, max_accel)
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for extra in self.extras:
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extra.set_max_jerk(max_halt_velocity, max_accel)
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def set_position(self, pos):
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PrinterHomingStepper.set_position(self, pos)
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for extra in self.extras:
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extra.set_position(pos)
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def motor_enable(self, print_time, enable=0):
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PrinterHomingStepper.motor_enable(self, print_time, enable)
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for extra in self.extras:
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extra.motor_enable(print_time, enable)
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def get_endstops(self):
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return self.endstops
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def LookupMultiHomingStepper(printer, config):
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if not config.has_section(config.section + '1'):
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return PrinterHomingStepper(printer, config)
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return PrinterMultiStepper(printer, config)
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