klipper/klippy/stepper.py

209 lines
9.9 KiB
Python

# Printer stepper support
#
# Copyright (C) 2016-2018 Kevin O'Connor <kevin@koconnor.net>
#
# This file may be distributed under the terms of the GNU GPLv3 license.
import math, logging
import homing, pins
# Tracking of shared stepper enable pins
class StepperEnablePin:
def __init__(self, mcu_enable, enable_count=0):
self.mcu_enable = mcu_enable
self.enable_count = enable_count
def set_enable(self, print_time, enable):
if enable:
if not self.enable_count:
self.mcu_enable.set_digital(print_time, 1)
self.enable_count += 1
else:
self.enable_count -= 1
if not self.enable_count:
self.mcu_enable.set_digital(print_time, 0)
def lookup_enable_pin(printer, pin):
if pin is None:
return StepperEnablePin(None, 9999)
pin_params = pins.get_printer_pins(printer).lookup_pin(
'digital_out', pin, 'stepper_enable')
enable = pin_params.get('class')
if enable is None:
mcu_enable = pin_params['chip'].setup_pin(pin_params)
mcu_enable.setup_max_duration(0.)
pin_params['class'] = enable = StepperEnablePin(mcu_enable)
return enable
# Code storing the definitions for a stepper motor
class PrinterStepper:
def __init__(self, printer, config):
self.name = config.get_name()
if self.name.startswith('stepper_'):
self.name = self.name[8:]
self.need_motor_enable = True
# Stepper definition
self.mcu_stepper = pins.setup_pin(
printer, 'stepper', config.get('step_pin'))
dir_pin_params = pins.get_printer_pins(printer).lookup_pin(
'digital_out', config.get('dir_pin'))
self.mcu_stepper.setup_dir_pin(dir_pin_params)
self.step_dist = config.getfloat('step_distance', above=0.)
self.mcu_stepper.setup_step_distance(self.step_dist)
self.step = self.mcu_stepper.step
self.step_const = self.mcu_stepper.step_const
self.step_delta = self.mcu_stepper.step_delta
self.enable = lookup_enable_pin(printer, config.get('enable_pin', None))
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.setup_min_stop_interval(min_stop_interval)
def set_position(self, pos):
self.mcu_stepper.set_position(pos)
def motor_enable(self, print_time, enable=0):
if self.need_motor_enable != (not enable):
self.enable.set_enable(print_time, enable)
self.need_motor_enable = not enable
# Support for stepper controlled linear axis with an endstop
class PrinterHomingStepper(PrinterStepper):
def __init__(self, printer, config, default_position=None):
PrinterStepper.__init__(self, printer, config)
# Endstop and its position
self.mcu_endstop = pins.setup_pin(
printer, 'endstop', config.get('endstop_pin'))
self.mcu_endstop.add_stepper(self.mcu_stepper)
if default_position is None:
self.position_endstop = config.getfloat('position_endstop')
else:
self.position_endstop = config.getfloat(
'position_endstop', default_position)
# Axis range
self.position_min = config.getfloat('position_min', 0.)
self.position_max = config.getfloat(
'position_max', 0., above=self.position_min)
# Homing mechanics
self.homing_speed = config.getfloat('homing_speed', 5.0, above=0.)
self.homing_retract_dist = config.getfloat(
'homing_retract_dist', 5., above=0.)
self.homing_positive_dir = config.getboolean('homing_positive_dir', None)
if self.homing_positive_dir is None:
axis_len = self.position_max - self.position_min
if self.position_endstop <= self.position_min + axis_len / 4.:
self.homing_positive_dir = False
elif self.position_endstop >= self.position_max - axis_len / 4.:
self.homing_positive_dir = True
else:
raise config.error(
"Unable to infer homing_positive_dir in section '%s'" % (
config.get_name(),))
# Endstop stepper phase position tracking
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 (self.homing_endstop_phase is not None
and config.getboolean('homing_endstop_align_zero', False)):
# Adjust the endstop position so 0.0 is always at a full step
micro_steps = self.homing_stepper_phases // 4
phase_offset = (
((self.homing_endstop_phase + micro_steps // 2) % micro_steps)
- micro_steps // 2) * self.step_dist
full_step = micro_steps * self.step_dist
es_pos = (int(self.position_endstop / full_step + .5) * full_step
+ phase_offset)
if es_pos != self.position_endstop:
logging.info("Changing %s endstop position to %.3f"
" (from %.3f)", self.name, es_pos,
self.position_endstop)
self.position_endstop = es_pos
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 * .5 / self.step_dist))
else:
self.homing_endstop_accuracy = int(math.ceil(
endstop_accuracy / self.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 self.mcu_endstop.get_mcu().is_fileoutput():
self.homing_endstop_accuracy = self.homing_stepper_phases
def get_endstops(self):
return [(self.mcu_endstop, self.name)]
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
# Wrapper for dual stepper motor support
class PrinterMultiStepper(PrinterHomingStepper):
def __init__(self, printer, config):
PrinterHomingStepper.__init__(self, printer, config)
self.endstops = PrinterHomingStepper.get_endstops(self)
self.extras = []
self.all_step_const = [self.step_const]
for i in range(1, 99):
if not config.has_section(config.get_name() + str(i)):
break
extraconfig = config.getsection(config.get_name() + str(i))
extra = PrinterStepper(printer, extraconfig)
self.extras.append(extra)
self.all_step_const.append(extra.step_const)
extraendstop = extraconfig.get('endstop_pin', None)
if extraendstop is not None:
mcu_endstop = pins.setup_pin(printer, 'endstop', extraendstop)
mcu_endstop.add_stepper(extra.mcu_stepper)
self.endstops.append((mcu_endstop, extra.name))
else:
self.mcu_endstop.add_stepper(extra.mcu_stepper)
self.step_const = self.step_multi_const
def step_multi_const(self, print_time, start_pos, dist, start_v, accel):
for step_const in self.all_step_const:
step_const(print_time, start_pos, dist, start_v, accel)
def set_max_jerk(self, max_halt_velocity, max_accel):
PrinterHomingStepper.set_max_jerk(self, max_halt_velocity, max_accel)
for extra in self.extras:
extra.set_max_jerk(max_halt_velocity, max_accel)
def set_position(self, pos):
PrinterHomingStepper.set_position(self, pos)
for extra in self.extras:
extra.set_position(pos)
def motor_enable(self, print_time, enable=0):
PrinterHomingStepper.motor_enable(self, print_time, enable)
for extra in self.extras:
extra.motor_enable(print_time, enable)
def get_endstops(self):
return self.endstops
def LookupMultiHomingStepper(printer, config):
if not config.has_section(config.get_name() + '1'):
return PrinterHomingStepper(printer, config)
return PrinterMultiStepper(printer, config)