CreatBotKlipper/klippy/stepper.py
Kevin O'Connor 143b7cccf4 stepper: Separate out homing code to its own PrinterHomingStepper class
Keep the homing code separate from the main stepper class.  This makes
it easier to verify the correct config parameters are provided.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>
2017-07-24 13:54:46 -04:00

112 lines
5.4 KiB
Python

# Printer stepper support
#
# Copyright (C) 2016 Kevin O'Connor <kevin@koconnor.net>
#
# This file may be distributed under the terms of the GNU GPLv3 license.
import math, logging
import homing
class PrinterStepper:
def __init__(self, printer, config, name):
self.name = name
self.step_dist = config.getfloat('step_distance', above=0.)
self.inv_step_dist = 1. / self.step_dist
self.min_stop_interval = 0.
step_pin = config.get('step_pin')
dir_pin = config.get('dir_pin')
self.mcu_stepper = printer.mcu.create_stepper(step_pin, dir_pin)
self.mcu_stepper.set_step_distance(self.step_dist)
enable_pin = config.get('enable_pin', None)
if enable_pin is not None:
self.mcu_enable = printer.mcu.create_digital_out(enable_pin, 0)
self.need_motor_enable = True
def _dist_to_time(self, dist, start_velocity, accel):
# Calculate the time it takes to travel a distance with constant accel
time_offset = start_velocity / accel
return math.sqrt(2. * dist / accel + time_offset**2) - time_offset
def set_max_jerk(self, max_halt_velocity, max_accel):
# Calculate the firmware's maximum halt interval time
last_step_time = self._dist_to_time(
self.step_dist, max_halt_velocity, max_accel)
second_last_step_time = self._dist_to_time(
2. * self.step_dist, max_halt_velocity, max_accel)
min_stop_interval = second_last_step_time - last_step_time
self.mcu_stepper.set_min_stop_interval(min_stop_interval)
def motor_enable(self, move_time, enable=0):
if enable and self.need_motor_enable:
mcu_time = self.mcu_stepper.print_to_mcu_time(move_time)
self.mcu_stepper.reset_step_clock(mcu_time)
if (self.mcu_enable is not None
and self.mcu_enable.get_last_setting() != enable):
mcu_time = self.mcu_enable.print_to_mcu_time(move_time)
self.mcu_enable.set_digital(mcu_time, enable)
self.need_motor_enable = not enable
class PrinterHomingStepper(PrinterStepper):
def __init__(self, printer, config, name):
PrinterStepper.__init__(self, printer, config, name)
endstop_pin = config.get('endstop_pin', None)
self.mcu_endstop = printer.mcu.create_endstop(endstop_pin)
self.mcu_endstop.add_stepper(self.mcu_stepper)
self.position_min = config.getfloat('position_min', 0.)
self.position_max = config.getfloat(
'position_max', 0., above=self.position_min)
self.position_endstop = config.getfloat('position_endstop')
self.homing_speed = config.getfloat('homing_speed', 5.0, above=0.)
self.homing_positive_dir = config.getboolean(
'homing_positive_dir', False)
self.homing_retract_dist = config.getfloat(
'homing_retract_dist', 5., above=0.)
self.homing_stepper_phases = config.getint(
'homing_stepper_phases', None, minval=0)
endstop_accuracy = config.getfloat(
'homing_endstop_accuracy', None, above=0.)
self.homing_endstop_accuracy = self.homing_endstop_phase = None
if self.homing_stepper_phases:
self.homing_endstop_phase = config.getint(
'homing_endstop_phase', None, minval=0
, maxval=self.homing_stepper_phases-1)
if endstop_accuracy is None:
self.homing_endstop_accuracy = self.homing_stepper_phases//2 - 1
elif self.homing_endstop_phase is not None:
self.homing_endstop_accuracy = int(math.ceil(
endstop_accuracy * self.inv_step_dist / 2.))
else:
self.homing_endstop_accuracy = int(math.ceil(
endstop_accuracy * self.inv_step_dist))
if self.homing_endstop_accuracy >= self.homing_stepper_phases // 2:
logging.info("Endstop for %s is not accurate enough for stepper"
" phase adjustment" % (name,))
self.homing_stepper_phases = None
if printer.mcu.is_fileoutput():
self.homing_endstop_accuracy = self.homing_stepper_phases
def enable_endstop_checking(self, move_time, step_time):
mcu_time = self.mcu_endstop.print_to_mcu_time(move_time)
self.mcu_endstop.home_start(mcu_time, step_time)
return self.mcu_endstop
def query_endstop(self, print_time):
mcu_time = self.mcu_endstop.print_to_mcu_time(print_time)
self.mcu_endstop.query_endstop(mcu_time)
return self.mcu_endstop
def get_homed_offset(self):
if not self.homing_stepper_phases or self.need_motor_enable:
return 0
pos = self.mcu_stepper.get_mcu_position()
pos %= self.homing_stepper_phases
if self.homing_endstop_phase is None:
logging.info("Setting %s endstop phase to %d" % (self.name, pos))
self.homing_endstop_phase = pos
return 0
delta = (pos - self.homing_endstop_phase) % self.homing_stepper_phases
if delta >= self.homing_stepper_phases - self.homing_endstop_accuracy:
delta -= self.homing_stepper_phases
elif delta > self.homing_endstop_accuracy:
raise homing.EndstopError(
"Endstop %s incorrect phase (got %d vs %d)" % (
self.name, pos, self.homing_endstop_phase))
return delta * self.step_dist