klipper/klippy/stepper.py

102 lines
5.0 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')
self.inv_step_dist = 1. / self.step_dist
self.min_stop_interval = 0.
self.homing_speed = config.getfloat('homing_speed', 5.0)
self.homing_positive_dir = config.getboolean(
'homing_positive_dir', False)
self.homing_retract_dist = config.getfloat('homing_retract_dist', 5.)
self.homing_stepper_phases = config.getint('homing_stepper_phases', None)
self.homing_endstop_phase = config.getint('homing_endstop_phase', None)
endstop_accuracy = config.getfloat('homing_endstop_accuracy', None)
self.homing_endstop_accuracy = None
if self.homing_stepper_phases:
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
self.position_min = self.position_endstop = self.position_max = None
endstop_pin = config.get('endstop_pin', None)
step_pin = config.get('step_pin')
dir_pin = config.get('dir_pin')
mcu = printer.mcu
self.mcu_stepper = mcu.create_stepper(step_pin, dir_pin)
enable_pin = config.get('enable_pin', None)
if enable_pin is not None:
self.mcu_enable = mcu.create_digital_out(enable_pin, 0)
if endstop_pin is not None:
self.mcu_endstop = mcu.create_endstop(endstop_pin)
self.mcu_endstop.add_stepper(self.mcu_stepper)
self.position_min = config.getfloat('position_min', 0.)
self.position_endstop = config.getfloat('position_endstop')
self.position_max = config.getfloat('position_max', 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
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