360 lines
16 KiB
Python
360 lines
16 KiB
Python
# Printer stepper support
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#
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# Copyright (C) 2016-2019 Kevin O'Connor <kevin@koconnor.net>
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#
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# This file may be distributed under the terms of the GNU GPLv3 license.
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import math, logging, collections
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import chelper
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class error(Exception):
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pass
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######################################################################
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# Steppers
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######################################################################
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# Interface to low-level mcu and chelper code
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class MCU_stepper:
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def __init__(self, name, step_pin_params, dir_pin_params, step_dist,
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units_in_radians=False):
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self._name = name
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self._step_dist = step_dist
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self._units_in_radians = units_in_radians
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self._mcu = step_pin_params['chip']
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self._oid = oid = self._mcu.create_oid()
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self._mcu.register_config_callback(self._build_config)
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self._step_pin = step_pin_params['pin']
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self._invert_step = step_pin_params['invert']
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if dir_pin_params['chip'] is not self._mcu:
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raise self._mcu.get_printer().config_error(
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"Stepper dir pin must be on same mcu as step pin")
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self._dir_pin = dir_pin_params['pin']
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self._invert_dir = dir_pin_params['invert']
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self._mcu_position_offset = self._tag_position = 0.
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self._min_stop_interval = 0.
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self._reset_cmd_id = self._get_position_cmd = None
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self._active_callbacks = []
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ffi_main, self._ffi_lib = chelper.get_ffi()
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self._stepqueue = ffi_main.gc(self._ffi_lib.stepcompress_alloc(oid),
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self._ffi_lib.stepcompress_free)
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self._mcu.register_stepqueue(self._stepqueue)
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self._stepper_kinematics = None
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self._itersolve_generate_steps = self._ffi_lib.itersolve_generate_steps
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self._itersolve_check_active = self._ffi_lib.itersolve_check_active
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self._trapq = ffi_main.NULL
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def get_mcu(self):
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return self._mcu
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def get_name(self, short=False):
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if short and self._name.startswith('stepper_'):
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return self._name[8:]
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return self._name
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def units_in_radians(self):
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# Returns true if distances are in radians instead of millimeters
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return self._units_in_radians
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def _dist_to_time(self, dist, start_velocity, accel):
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# Calculate the time it takes to travel a distance with constant accel
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time_offset = start_velocity / accel
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return math.sqrt(2. * dist / accel + time_offset**2) - time_offset
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def set_max_jerk(self, max_halt_velocity, max_accel):
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# Calculate the firmware's maximum halt interval time
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last_step_time = self._dist_to_time(self._step_dist,
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max_halt_velocity, max_accel)
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second_last_step_time = self._dist_to_time(2. * self._step_dist,
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max_halt_velocity, max_accel)
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self._min_stop_interval = second_last_step_time - last_step_time
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def setup_itersolve(self, alloc_func, *params):
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ffi_main, ffi_lib = chelper.get_ffi()
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sk = ffi_main.gc(getattr(ffi_lib, alloc_func)(*params), ffi_lib.free)
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self.set_stepper_kinematics(sk)
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def _build_config(self):
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max_error = self._mcu.get_max_stepper_error()
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min_stop_interval = max(0., self._min_stop_interval - max_error)
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self._mcu.add_config_cmd(
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"config_stepper oid=%d step_pin=%s dir_pin=%s"
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" min_stop_interval=%d invert_step=%d" % (
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self._oid, self._step_pin, self._dir_pin,
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self._mcu.seconds_to_clock(min_stop_interval),
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self._invert_step))
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self._mcu.add_config_cmd("reset_step_clock oid=%d clock=0"
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% (self._oid,), on_restart=True)
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step_cmd_id = self._mcu.lookup_command_id(
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"queue_step oid=%c interval=%u count=%hu add=%hi")
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dir_cmd_id = self._mcu.lookup_command_id(
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"set_next_step_dir oid=%c dir=%c")
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self._reset_cmd_id = self._mcu.lookup_command_id(
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"reset_step_clock oid=%c clock=%u")
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self._get_position_cmd = self._mcu.lookup_query_command(
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"stepper_get_position oid=%c",
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"stepper_position oid=%c pos=%i", oid=self._oid)
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self._ffi_lib.stepcompress_fill(
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self._stepqueue, self._mcu.seconds_to_clock(max_error),
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self._invert_dir, step_cmd_id, dir_cmd_id)
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def get_oid(self):
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return self._oid
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def get_step_dist(self):
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return self._step_dist
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def set_step_dist(self, dist):
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self._step_dist = dist
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self.set_stepper_kinematics(self._stepper_kinematics)
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def is_dir_inverted(self):
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return self._invert_dir
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def calc_position_from_coord(self, coord):
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return self._ffi_lib.itersolve_calc_position_from_coord(
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self._stepper_kinematics, coord[0], coord[1], coord[2])
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def set_position(self, coord):
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opos = self.get_commanded_position()
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sk = self._stepper_kinematics
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self._ffi_lib.itersolve_set_position(sk, coord[0], coord[1], coord[2])
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self._mcu_position_offset += opos - self.get_commanded_position()
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def get_commanded_position(self):
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sk = self._stepper_kinematics
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return self._ffi_lib.itersolve_get_commanded_pos(sk)
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def get_mcu_position(self):
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mcu_pos_dist = self.get_commanded_position() + self._mcu_position_offset
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mcu_pos = mcu_pos_dist / self._step_dist
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if mcu_pos >= 0.:
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return int(mcu_pos + 0.5)
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return int(mcu_pos - 0.5)
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def get_tag_position(self):
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return self._tag_position
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def set_tag_position(self, position):
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self._tag_position = position
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def set_stepper_kinematics(self, sk):
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old_sk = self._stepper_kinematics
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self._stepper_kinematics = sk
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if sk is not None:
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self._ffi_lib.itersolve_set_stepcompress(sk, self._stepqueue,
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self._step_dist)
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self.set_trapq(self._trapq)
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return old_sk
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def note_homing_end(self, did_trigger=False):
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ret = self._ffi_lib.stepcompress_reset(self._stepqueue, 0)
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if ret:
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raise error("Internal error in stepcompress")
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data = (self._reset_cmd_id, self._oid, 0)
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ret = self._ffi_lib.stepcompress_queue_msg(
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self._stepqueue, data, len(data))
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if ret:
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raise error("Internal error in stepcompress")
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if not did_trigger or self._mcu.is_fileoutput():
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return
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params = self._get_position_cmd.send([self._oid])
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mcu_pos_dist = params['pos'] * self._step_dist
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if self._invert_dir:
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mcu_pos_dist = -mcu_pos_dist
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self._mcu_position_offset = mcu_pos_dist - self.get_commanded_position()
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def set_trapq(self, tq):
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if tq is None:
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ffi_main, self._ffi_lib = chelper.get_ffi()
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tq = ffi_main.NULL
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self._ffi_lib.itersolve_set_trapq(self._stepper_kinematics, tq)
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old_tq = self._trapq
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self._trapq = tq
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return old_tq
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def add_active_callback(self, cb):
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self._active_callbacks.append(cb)
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def generate_steps(self, flush_time):
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# Check for activity if necessary
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if self._active_callbacks:
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ret = self._itersolve_check_active(self._stepper_kinematics,
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flush_time)
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if ret:
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cbs = self._active_callbacks
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self._active_callbacks = []
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for cb in cbs:
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cb(ret)
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# Generate steps
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ret = self._itersolve_generate_steps(self._stepper_kinematics,
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flush_time)
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if ret:
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raise error("Internal error in stepcompress")
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def is_active_axis(self, axis):
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return self._ffi_lib.itersolve_is_active_axis(
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self._stepper_kinematics, axis)
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# Helper code to build a stepper object from a config section
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def PrinterStepper(config, units_in_radians=False):
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printer = config.get_printer()
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name = config.get_name()
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# Stepper definition
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ppins = printer.lookup_object('pins')
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step_pin = config.get('step_pin')
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step_pin_params = ppins.lookup_pin(step_pin, can_invert=True)
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dir_pin = config.get('dir_pin')
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dir_pin_params = ppins.lookup_pin(dir_pin, can_invert=True)
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step_dist = parse_step_distance(config, units_in_radians, True)
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mcu_stepper = MCU_stepper(name, step_pin_params, dir_pin_params, step_dist,
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units_in_radians)
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# Support for stepper enable pin handling
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stepper_enable = printer.load_object(config, 'stepper_enable')
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stepper_enable.register_stepper(mcu_stepper, config.get('enable_pin', None))
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# Register STEPPER_BUZZ command
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force_move = printer.load_object(config, 'force_move')
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force_move.register_stepper(mcu_stepper)
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return mcu_stepper
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# Parse stepper gear_ratio config parameter
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def parse_gear_ratio(config, note_valid):
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gear_ratio = config.get('gear_ratio', None, note_valid=note_valid)
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if gear_ratio is None:
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return 1.
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result = 1.
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try:
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gears = gear_ratio.split(',')
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for gear in gears:
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g1, g2 = [float(v.strip()) for v in gear.split(':')]
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result *= g1 / g2
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except:
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raise config.error("Unable to parse gear_ratio: %s" % (gear_ratio,))
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return result
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# Obtain "step distance" information from a config section
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def parse_step_distance(config, units_in_radians=None, note_valid=False):
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if units_in_radians is None:
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# Caller doesn't know if units are in radians - infer it
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rd = config.get('rotation_distance', None, note_valid=False)
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gr = config.get('gear_ratio', None, note_valid=False)
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units_in_radians = rd is None and gr is not None
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if units_in_radians:
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rotation_dist = 2. * math.pi
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config.get('gear_ratio', note_valid=note_valid)
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else:
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rotation_dist = config.getfloat('rotation_distance', None,
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above=0., note_valid=note_valid)
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if rotation_dist is None:
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# Older config format with step_distance
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return config.getfloat('step_distance', above=0., note_valid=note_valid)
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# Newer config format with rotation_distance
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microsteps = config.getint('microsteps', minval=1, note_valid=note_valid)
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full_steps = config.getint('full_steps_per_rotation', 200, minval=1,
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note_valid=note_valid)
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if full_steps % 4:
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raise config.error("full_steps_per_rotation invalid in section '%s'"
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% (config.get_name(),))
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gearing = parse_gear_ratio(config, note_valid)
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return rotation_dist / (full_steps * microsteps * gearing)
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######################################################################
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# Stepper controlled rails
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######################################################################
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# A motor control "rail" with one (or more) steppers and one (or more)
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# endstops.
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class PrinterRail:
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def __init__(self, config, need_position_minmax=True,
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default_position_endstop=None, units_in_radians=False):
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# Primary stepper and endstop
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self.stepper_units_in_radians = units_in_radians
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self.steppers = []
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self.endstops = []
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self.add_extra_stepper(config)
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mcu_stepper = self.steppers[0]
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self.get_commanded_position = mcu_stepper.get_commanded_position
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self.get_tag_position = mcu_stepper.get_tag_position
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self.set_tag_position = mcu_stepper.set_tag_position
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self.calc_position_from_coord = mcu_stepper.calc_position_from_coord
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# Primary endstop position
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mcu_endstop = self.endstops[0][0]
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if hasattr(mcu_endstop, "get_position_endstop"):
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self.position_endstop = mcu_endstop.get_position_endstop()
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elif default_position_endstop is None:
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self.position_endstop = config.getfloat('position_endstop')
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else:
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self.position_endstop = config.getfloat(
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'position_endstop', default_position_endstop)
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# Axis range
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if need_position_minmax:
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self.position_min = config.getfloat('position_min', 0.)
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self.position_max = config.getfloat(
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'position_max', above=self.position_min)
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else:
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self.position_min = 0.
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self.position_max = self.position_endstop
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if (self.position_endstop < self.position_min
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or self.position_endstop > self.position_max):
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raise config.error(
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"position_endstop in section '%s' must be between"
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" position_min and position_max" % config.get_name())
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# Homing mechanics
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self.homing_speed = config.getfloat('homing_speed', 5.0, above=0.)
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self.second_homing_speed = config.getfloat(
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'second_homing_speed', self.homing_speed/2., above=0.)
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self.homing_retract_speed = config.getfloat(
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'homing_retract_speed', self.homing_speed, above=0.)
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self.homing_retract_dist = config.getfloat(
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'homing_retract_dist', 5., minval=0.)
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self.homing_positive_dir = config.getboolean(
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'homing_positive_dir', None)
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if self.homing_positive_dir is None:
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axis_len = self.position_max - self.position_min
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if self.position_endstop <= self.position_min + axis_len / 4.:
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self.homing_positive_dir = False
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elif self.position_endstop >= self.position_max - axis_len / 4.:
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self.homing_positive_dir = True
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else:
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raise config.error(
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"Unable to infer homing_positive_dir in section '%s'" % (
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config.get_name(),))
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elif ((self.homing_positive_dir
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and self.position_endstop == self.position_min)
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or (not self.homing_positive_dir
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and self.position_endstop == self.position_max)):
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raise config.error(
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"Invalid homing_positive_dir / position_endstop in '%s'"
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% (config.get_name(),))
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def get_range(self):
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return self.position_min, self.position_max
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def get_homing_info(self):
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homing_info = collections.namedtuple('homing_info', [
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'speed', 'position_endstop', 'retract_speed', 'retract_dist',
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'positive_dir', 'second_homing_speed'])(
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self.homing_speed, self.position_endstop,
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self.homing_retract_speed, self.homing_retract_dist,
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self.homing_positive_dir, self.second_homing_speed)
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return homing_info
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def get_steppers(self):
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return list(self.steppers)
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def get_endstops(self):
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return list(self.endstops)
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def add_extra_stepper(self, config):
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stepper = PrinterStepper(config, self.stepper_units_in_radians)
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self.steppers.append(stepper)
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if self.endstops and config.get('endstop_pin', None) is None:
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# No endstop defined - use primary endstop
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self.endstops[0][0].add_stepper(stepper)
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return
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printer = config.get_printer()
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ppins = printer.lookup_object('pins')
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mcu_endstop = ppins.setup_pin('endstop', config.get('endstop_pin'))
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mcu_endstop.add_stepper(stepper)
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name = stepper.get_name(short=True)
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self.endstops.append((mcu_endstop, name))
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query_endstops = printer.load_object(config, 'query_endstops')
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query_endstops.register_endstop(mcu_endstop, name)
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def setup_itersolve(self, alloc_func, *params):
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for stepper in self.steppers:
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stepper.setup_itersolve(alloc_func, *params)
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def generate_steps(self, flush_time):
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for stepper in self.steppers:
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stepper.generate_steps(flush_time)
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def set_trapq(self, trapq):
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for stepper in self.steppers:
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stepper.set_trapq(trapq)
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def set_max_jerk(self, max_halt_velocity, max_accel):
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for stepper in self.steppers:
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stepper.set_max_jerk(max_halt_velocity, max_accel)
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def set_position(self, coord):
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for stepper in self.steppers:
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stepper.set_position(coord)
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# Wrapper for dual stepper motor support
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def LookupMultiRail(config):
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rail = PrinterRail(config)
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for i in range(1, 99):
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if not config.has_section(config.get_name() + str(i)):
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break
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rail.add_extra_stepper(config.getsection(config.get_name() + str(i)))
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return rail
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