klipper/klippy/stepper.py

372 lines
17 KiB
Python

# Printer stepper support
#
# Copyright (C) 2016-2021 Kevin O'Connor <kevin@koconnor.net>
#
# This file may be distributed under the terms of the GNU GPLv3 license.
import math, logging, collections
import chelper
class error(Exception):
pass
######################################################################
# Steppers
######################################################################
# Interface to low-level mcu and chelper code
class MCU_stepper:
def __init__(self, name, step_pin_params, dir_pin_params, step_dist,
units_in_radians=False):
self._name = name
self._step_dist = step_dist
self._units_in_radians = units_in_radians
self._mcu = step_pin_params['chip']
self._oid = oid = self._mcu.create_oid()
self._mcu.register_config_callback(self._build_config)
self._step_pin = step_pin_params['pin']
self._invert_step = step_pin_params['invert']
if dir_pin_params['chip'] is not self._mcu:
raise self._mcu.get_printer().config_error(
"Stepper dir pin must be on same mcu as step pin")
self._dir_pin = dir_pin_params['pin']
self._invert_dir = dir_pin_params['invert']
self._mcu_position_offset = 0.
self._reset_cmd_tag = self._get_position_cmd = None
self._active_callbacks = []
ffi_main, ffi_lib = chelper.get_ffi()
self._stepqueue = ffi_main.gc(ffi_lib.stepcompress_alloc(oid),
ffi_lib.stepcompress_free)
self._mcu.register_stepqueue(self._stepqueue)
self._stepper_kinematics = None
self._itersolve_generate_steps = ffi_lib.itersolve_generate_steps
self._itersolve_check_active = ffi_lib.itersolve_check_active
self._trapq = ffi_main.NULL
self._mcu.get_printer().register_event_handler('klippy:connect',
self._query_mcu_position)
def get_mcu(self):
return self._mcu
def get_name(self, short=False):
if short and self._name.startswith('stepper_'):
return self._name[8:]
return self._name
def units_in_radians(self):
# Returns true if distances are in radians instead of millimeters
return self._units_in_radians
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 setup_itersolve(self, alloc_func, *params):
ffi_main, ffi_lib = chelper.get_ffi()
sk = ffi_main.gc(getattr(ffi_lib, alloc_func)(*params), ffi_lib.free)
self.set_stepper_kinematics(sk)
def _build_config(self):
self._mcu.add_config_cmd(
"config_stepper oid=%d step_pin=%s dir_pin=%s invert_step=%d"
% (self._oid, self._step_pin, self._dir_pin, self._invert_step))
self._mcu.add_config_cmd("reset_step_clock oid=%d clock=0"
% (self._oid,), on_restart=True)
step_cmd_tag = self._mcu.lookup_command_tag(
"queue_step oid=%c interval=%u count=%hu add=%hi")
dir_cmd_tag = self._mcu.lookup_command_tag(
"set_next_step_dir oid=%c dir=%c")
self._reset_cmd_tag = self._mcu.lookup_command_tag(
"reset_step_clock oid=%c clock=%u")
self._get_position_cmd = self._mcu.lookup_query_command(
"stepper_get_position oid=%c",
"stepper_position oid=%c pos=%i", oid=self._oid)
max_error = self._mcu.get_max_stepper_error()
ffi_main, ffi_lib = chelper.get_ffi()
ffi_lib.stepcompress_fill(self._stepqueue,
self._mcu.seconds_to_clock(max_error),
self._invert_dir, step_cmd_tag, dir_cmd_tag)
def get_oid(self):
return self._oid
def get_step_dist(self):
return self._step_dist
def set_step_dist(self, dist):
mcu_pos = self.get_mcu_position()
self._step_dist = dist
self.set_stepper_kinematics(self._stepper_kinematics)
self._set_mcu_position(mcu_pos)
def is_dir_inverted(self):
return self._invert_dir
def calc_position_from_coord(self, coord):
ffi_main, ffi_lib = chelper.get_ffi()
return ffi_lib.itersolve_calc_position_from_coord(
self._stepper_kinematics, coord[0], coord[1], coord[2])
def set_position(self, coord):
mcu_pos = self.get_mcu_position()
sk = self._stepper_kinematics
ffi_main, ffi_lib = chelper.get_ffi()
ffi_lib.itersolve_set_position(sk, coord[0], coord[1], coord[2])
self._set_mcu_position(mcu_pos)
def get_commanded_position(self):
ffi_main, ffi_lib = chelper.get_ffi()
return ffi_lib.itersolve_get_commanded_pos(self._stepper_kinematics)
def get_mcu_position(self):
mcu_pos_dist = self.get_commanded_position() + self._mcu_position_offset
mcu_pos = mcu_pos_dist / self._step_dist
if mcu_pos >= 0.:
return int(mcu_pos + 0.5)
return int(mcu_pos - 0.5)
def _set_mcu_position(self, mcu_pos):
mcu_pos_dist = mcu_pos * self._step_dist
self._mcu_position_offset = mcu_pos_dist - self.get_commanded_position()
def get_past_mcu_position(self, print_time):
clock = self._mcu.print_time_to_clock(print_time)
ffi_main, ffi_lib = chelper.get_ffi()
pos = ffi_lib.stepcompress_find_past_position(self._stepqueue, clock)
return int(pos)
def mcu_to_commanded_position(self, mcu_pos):
return mcu_pos * self._step_dist - self._mcu_position_offset
def dump_steps(self, count, start_clock, end_clock):
ffi_main, ffi_lib = chelper.get_ffi()
data = ffi_main.new('struct pull_history_steps[]', count)
count = ffi_lib.stepcompress_extract_old(self._stepqueue, data, count,
start_clock, end_clock)
return (data, count)
def set_stepper_kinematics(self, sk):
old_sk = self._stepper_kinematics
mcu_pos = 0
if old_sk is not None:
mcu_pos = self.get_mcu_position()
self._stepper_kinematics = sk
ffi_main, ffi_lib = chelper.get_ffi()
ffi_lib.itersolve_set_stepcompress(sk, self._stepqueue, self._step_dist)
self.set_trapq(self._trapq)
self._set_mcu_position(mcu_pos)
return old_sk
def note_homing_end(self):
ffi_main, ffi_lib = chelper.get_ffi()
ret = ffi_lib.stepcompress_reset(self._stepqueue, 0)
if ret:
raise error("Internal error in stepcompress")
data = (self._reset_cmd_tag, self._oid, 0)
ret = ffi_lib.stepcompress_queue_msg(self._stepqueue, data, len(data))
if ret:
raise error("Internal error in stepcompress")
self._query_mcu_position()
def _query_mcu_position(self):
if self._mcu.is_fileoutput():
return
params = self._get_position_cmd.send([self._oid])
last_pos = params['pos']
if self._invert_dir:
last_pos = -last_pos
print_time = self._mcu.estimated_print_time(params['#receive_time'])
clock = self._mcu.print_time_to_clock(print_time)
ffi_main, ffi_lib = chelper.get_ffi()
ret = ffi_lib.stepcompress_set_last_position(self._stepqueue, clock,
last_pos)
if ret:
raise error("Internal error in stepcompress")
self._set_mcu_position(last_pos)
self._mcu.get_printer().send_event("stepper:sync_mcu_position", self)
def set_trapq(self, tq):
ffi_main, ffi_lib = chelper.get_ffi()
if tq is None:
tq = ffi_main.NULL
ffi_lib.itersolve_set_trapq(self._stepper_kinematics, tq)
old_tq = self._trapq
self._trapq = tq
return old_tq
def add_active_callback(self, cb):
self._active_callbacks.append(cb)
def generate_steps(self, flush_time):
# Check for activity if necessary
if self._active_callbacks:
sk = self._stepper_kinematics
ret = self._itersolve_check_active(sk, flush_time)
if ret:
cbs = self._active_callbacks
self._active_callbacks = []
for cb in cbs:
cb(ret)
# Generate steps
sk = self._stepper_kinematics
ret = self._itersolve_generate_steps(sk, flush_time)
if ret:
raise error("Internal error in stepcompress")
def is_active_axis(self, axis):
ffi_main, ffi_lib = chelper.get_ffi()
return ffi_lib.itersolve_is_active_axis(self._stepper_kinematics, axis)
# Helper code to build a stepper object from a config section
def PrinterStepper(config, units_in_radians=False):
printer = config.get_printer()
name = config.get_name()
# Stepper definition
ppins = printer.lookup_object('pins')
step_pin = config.get('step_pin')
step_pin_params = ppins.lookup_pin(step_pin, can_invert=True)
dir_pin = config.get('dir_pin')
dir_pin_params = ppins.lookup_pin(dir_pin, can_invert=True)
step_dist = parse_step_distance(config, units_in_radians, True)
mcu_stepper = MCU_stepper(name, step_pin_params, dir_pin_params, step_dist,
units_in_radians)
# Register with helper modules
for mname in ['stepper_enable', 'force_move', 'motion_report']:
m = printer.load_object(config, mname)
m.register_stepper(config, mcu_stepper)
return mcu_stepper
# Parse stepper gear_ratio config parameter
def parse_gear_ratio(config, note_valid):
gear_ratio = config.getlists('gear_ratio', (), seps=(':', ','), count=2,
parser=float, note_valid=note_valid)
result = 1.
for g1, g2 in gear_ratio:
result *= g1 / g2
return result
# Obtain "step distance" information from a config section
def parse_step_distance(config, units_in_radians=None, note_valid=False):
if units_in_radians is None:
# Caller doesn't know if units are in radians - infer it
rd = config.get('rotation_distance', None, note_valid=False)
gr = config.get('gear_ratio', None, note_valid=False)
units_in_radians = rd is None and gr is not None
if units_in_radians:
rotation_dist = 2. * math.pi
config.get('gear_ratio', note_valid=note_valid)
else:
rd = config.get('rotation_distance', None, note_valid=False)
sd = config.get('step_distance', None, note_valid=False)
if rd is None and sd is not None:
# Older config format with step_distance
return config.getfloat('step_distance', above=0.,
note_valid=note_valid)
rotation_dist = config.getfloat('rotation_distance', above=0.,
note_valid=note_valid)
# Newer config format with rotation_distance
microsteps = config.getint('microsteps', minval=1, note_valid=note_valid)
full_steps = config.getint('full_steps_per_rotation', 200, minval=1,
note_valid=note_valid)
if full_steps % 4:
raise config.error("full_steps_per_rotation invalid in section '%s'"
% (config.get_name(),))
gearing = parse_gear_ratio(config, note_valid)
return rotation_dist / (full_steps * microsteps * gearing)
######################################################################
# Stepper controlled rails
######################################################################
# A motor control "rail" with one (or more) steppers and one (or more)
# endstops.
class PrinterRail:
def __init__(self, config, need_position_minmax=True,
default_position_endstop=None, units_in_radians=False):
# Primary stepper and endstop
self.stepper_units_in_radians = units_in_radians
self.steppers = []
self.endstops = []
self.add_extra_stepper(config)
mcu_stepper = self.steppers[0]
self.get_name = mcu_stepper.get_name
self.get_commanded_position = mcu_stepper.get_commanded_position
self.calc_position_from_coord = mcu_stepper.calc_position_from_coord
# Primary endstop position
mcu_endstop = self.endstops[0][0]
if hasattr(mcu_endstop, "get_position_endstop"):
self.position_endstop = mcu_endstop.get_position_endstop()
elif 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.second_homing_speed = config.getfloat(
'second_homing_speed', self.homing_speed/2., above=0.)
self.homing_retract_speed = config.getfloat(
'homing_retract_speed', self.homing_speed, 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(),))
config.getboolean('homing_positive_dir', self.homing_positive_dir)
elif ((self.homing_positive_dir
and self.position_endstop == self.position_min)
or (not self.homing_positive_dir
and self.position_endstop == self.position_max)):
raise config.error(
"Invalid homing_positive_dir / position_endstop in '%s'"
% (config.get_name(),))
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_speed', 'retract_dist',
'positive_dir', 'second_homing_speed'])(
self.homing_speed, self.position_endstop,
self.homing_retract_speed, self.homing_retract_dist,
self.homing_positive_dir, self.second_homing_speed)
return homing_info
def get_steppers(self):
return list(self.steppers)
def get_endstops(self):
return list(self.endstops)
def add_extra_stepper(self, config):
stepper = PrinterStepper(config, self.stepper_units_in_radians)
self.steppers.append(stepper)
if self.endstops and config.get('endstop_pin', None) is None:
# No endstop defined - use primary endstop
self.endstops[0][0].add_stepper(stepper)
return
printer = config.get_printer()
ppins = printer.lookup_object('pins')
mcu_endstop = ppins.setup_pin('endstop', config.get('endstop_pin'))
mcu_endstop.add_stepper(stepper)
name = stepper.get_name(short=True)
self.endstops.append((mcu_endstop, name))
query_endstops = printer.load_object(config, 'query_endstops')
query_endstops.register_endstop(mcu_endstop, name)
def setup_itersolve(self, alloc_func, *params):
for stepper in self.steppers:
stepper.setup_itersolve(alloc_func, *params)
def generate_steps(self, flush_time):
for stepper in self.steppers:
stepper.generate_steps(flush_time)
def set_trapq(self, trapq):
for stepper in self.steppers:
stepper.set_trapq(trapq)
def set_position(self, coord):
for stepper in self.steppers:
stepper.set_position(coord)
# Wrapper for dual stepper motor support
def LookupMultiRail(config):
rail = PrinterRail(config)
for i in range(1, 99):
if not config.has_section(config.get_name() + str(i)):
break
rail.add_extra_stepper(config.getsection(config.get_name() + str(i)))
return rail