122 lines
5.9 KiB
Python
122 lines
5.9 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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class PrinterStepper:
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def __init__(self, printer, config, name):
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self.name = name
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self.step_dist = config.getfloat('step_distance', above=0.)
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self.inv_step_dist = 1. / self.step_dist
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self.min_stop_interval = 0.
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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.mcu_stepper.setup_step_distance(self.step_dist)
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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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self.need_motor_enable = True
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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 motor_enable(self, print_time, enable=0):
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if enable and self.need_motor_enable:
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self.mcu_stepper.reset_step_clock(print_time)
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if (self.mcu_enable is not None
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and self.mcu_enable.get_last_setting() != 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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class PrinterHomingStepper(PrinterStepper):
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def __init__(self, printer, config, name):
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PrinterStepper.__init__(self, printer, config, name)
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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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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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self.position_endstop = config.getfloat('position_endstop')
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self.homing_speed = config.getfloat('homing_speed', 5.0, 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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self.homing_retract_dist = config.getfloat(
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'homing_retract_dist', 5., above=0.)
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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 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 * self.inv_step_dist / 2.))
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else:
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self.homing_endstop_accuracy = int(math.ceil(
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endstop_accuracy * self.inv_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_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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