klipper/klippy/stepper.py

253 lines
12 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, collections
import homing, chelper
# 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(ppins, pin):
if pin is None:
return StepperEnablePin(None, 9999)
pin_params = ppins.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, config):
printer = config.get_printer()
self.name = config.get_name()
self.need_motor_enable = True
# Stepper definition
ppins = printer.lookup_object('pins')
self.mcu_stepper = ppins.setup_pin('stepper', config.get('step_pin'))
dir_pin_params = ppins.lookup_pin('digital_out', config.get('dir_pin'))
self.mcu_stepper.setup_dir_pin(dir_pin_params)
step_dist = config.getfloat('step_distance', above=0.)
self.mcu_stepper.setup_step_distance(step_dist)
self.enable = lookup_enable_pin(ppins, config.get('enable_pin', None))
# Register STEPPER_BUZZ command
stepper_buzz = printer.try_load_module(config, 'stepper_buzz')
stepper_buzz.register_stepper(self, config.get_name())
# Wrappers
self.step_itersolve = self.mcu_stepper.step_itersolve
self.setup_itersolve = self.mcu_stepper.setup_itersolve
self.set_ignore_move = self.mcu_stepper.set_ignore_move
self.get_mcu_position = self.mcu_stepper.get_mcu_position
self.get_commanded_position = self.mcu_stepper.get_commanded_position
self.get_step_dist = self.mcu_stepper.get_step_dist
def get_name(self, short=False):
if short and self.name.startswith('stepper_'):
return self.name[8:]
return self.name
def add_to_endstop(self, mcu_endstop):
mcu_endstop.add_stepper(self.mcu_stepper)
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
step_dist = self.get_step_dist()
last_step_time = self._dist_to_time(
step_dist, max_halt_velocity, max_accel)
second_last_step_time = self._dist_to_time(
2. * 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
def is_motor_enabled(self):
return not self.need_motor_enable
# Support for stepper controlled linear axis with an endstop
class PrinterHomingStepper(PrinterStepper):
def __init__(self, config, need_position_minmax=True,
default_position_endstop=None):
PrinterStepper.__init__(self, config)
# Endstop and its position
ppins = config.get_printer().lookup_object('pins')
self.mcu_endstop = ppins.setup_pin('endstop', config.get('endstop_pin'))
self.add_to_endstop(self.mcu_endstop)
if default_position_endstop is None:
self.position_endstop = config.getfloat('position_endstop')
else:
self.position_endstop = config.getfloat(
'position_endstop', default_position_endstop)
# Axis range
if need_position_minmax:
self.position_min = config.getfloat('position_min', 0.)
self.position_max = config.getfloat(
'position_max', above=self.position_min)
else:
self.position_min = 0.
self.position_max = self.position_endstop
if (self.position_endstop < self.position_min
or self.position_endstop > self.position_max):
raise config.error(
"position_endstop in section '%s' must be between"
" position_min and position_max" % config.get_name())
# Homing mechanics
self.homing_speed = config.getfloat('homing_speed', 5.0, above=0.)
self.homing_retract_dist = config.getfloat(
'homing_retract_dist', 5., minval=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:
step_dist = self.get_step_dist()
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) * step_dist
full_step = micro_steps * 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.get_name(short=True),
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 / step_dist))
else:
self.homing_endstop_accuracy = int(math.ceil(
endstop_accuracy / 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", self.get_name(short=True))
self.homing_stepper_phases = None
if self.mcu_endstop.get_mcu().is_fileoutput():
self.homing_endstop_accuracy = self.homing_stepper_phases
def setup_cartesian_itersolve(self, axis):
ffi_main, ffi_lib = chelper.get_ffi()
self.setup_itersolve(ffi_main.gc(
ffi_lib.cartesian_stepper_alloc(axis), ffi_lib.free))
def get_range(self):
return self.position_min, self.position_max
def get_homing_info(self):
homing_info = collections.namedtuple('homing_info', [
'speed', 'position_endstop', 'retract_dist', 'positive_dir'])(
self.homing_speed, self.position_endstop,
self.homing_retract_dist, self.homing_positive_dir)
return homing_info
def get_endstops(self):
return [(self.mcu_endstop, self.get_name(short=True))]
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.get_name(short=True), 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.get_name(short=True), pos, self.homing_endstop_phase))
return delta * self.get_step_dist()
# Wrapper for dual stepper motor support
class PrinterMultiStepper(PrinterHomingStepper):
def __init__(self, config):
PrinterHomingStepper.__init__(self, config)
self.endstops = PrinterHomingStepper.get_endstops(self)
self.extras = []
self.all_step_itersolve = [self.step_itersolve]
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(extraconfig)
self.extras.append(extra)
self.all_step_itersolve.append(extra.step_itersolve)
mcu_endstop = self.mcu_endstop
extraendstop = extraconfig.get('endstop_pin', None)
if extraendstop is not None:
ppins = config.get_printer().lookup_object('pins')
mcu_endstop = ppins.setup_pin('endstop', extraendstop)
self.endstops.append((mcu_endstop, extra.get_name(short=True)))
extra.add_to_endstop(mcu_endstop)
self.step_itersolve = self.step_multi_itersolve
def step_multi_itersolve(self, cmove):
for step_itersolve in self.all_step_itersolve:
step_itersolve(cmove)
def setup_cartesian_itersolve(self, axis):
ffi_main, ffi_lib = chelper.get_ffi()
self.setup_itersolve(ffi_main.gc(
ffi_lib.cartesian_stepper_alloc(axis), ffi_lib.free))
for extra in self.extras:
extra.setup_itersolve(ffi_main.gc(
ffi_lib.cartesian_stepper_alloc(axis), ffi_lib.free))
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(config):
if not config.has_section(config.get_name() + '1'):
return PrinterHomingStepper(config)
return PrinterMultiStepper(config)