# 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
######################################################################
# Stepper enable 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(ppins, pin):
if pin is None:
return StepperEnablePin(None, 9999)
pin_params = ppins.lookup_pin(pin, can_invert=True,
share_type='stepper_enable')
enable = pin_params.get('class')
if enable is None:
mcu_enable = pin_params['chip'].setup_pin('digital_out', pin_params)
mcu_enable.setup_max_duration(0.)
pin_params['class'] = enable = StepperEnablePin(mcu_enable)
return enable
######################################################################
# Steppers
######################################################################
# 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')
step_pin = config.get('step_pin')
self.mcu_stepper = mcu_stepper = ppins.setup_pin('stepper', step_pin)
dir_pin = config.get('dir_pin')
dir_pin_params = ppins.lookup_pin(dir_pin, can_invert=True)
mcu_stepper.setup_dir_pin(dir_pin_params)
step_dist = config.getfloat('step_distance', above=0.)
mcu_stepper.setup_step_distance(step_dist)
self.enable = lookup_enable_pin(ppins, config.get('enable_pin', None))
# Register STEPPER_BUZZ command
force_move = printer.try_load_module(config, 'force_move')
force_move.register_stepper(self)
# Wrappers
self.step_itersolve = mcu_stepper.step_itersolve
self.setup_itersolve = mcu_stepper.setup_itersolve
self.set_stepper_kinematics = mcu_stepper.set_stepper_kinematics
self.set_ignore_move = mcu_stepper.set_ignore_move
self.calc_position_from_coord = mcu_stepper.calc_position_from_coord
self.set_position = mcu_stepper.set_position
self.get_commanded_position = mcu_stepper.get_commanded_position
self.set_commanded_position = mcu_stepper.set_commanded_position
self.get_mcu_position = mcu_stepper.get_mcu_position
self.get_step_dist = 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 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
######################################################################
# 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):
# Primary stepper
stepper = PrinterStepper(config)
self.steppers = [stepper]
self.name = stepper.get_name(short=True)
self.step_itersolve = stepper.step_itersolve
self.get_commanded_position = stepper.get_commanded_position
self.is_motor_enabled = stepper.is_motor_enabled
# Primary endstop and its position
printer = config.get_printer()
ppins = printer.lookup_object('pins')
mcu_endstop = ppins.setup_pin('endstop', config.get('endstop_pin'))
self.endstops = [(mcu_endstop, self.name)]
stepper.add_to_endstop(mcu_endstop)
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)
query_endstops = printer.try_load_module(config, 'query_endstops')
query_endstops.register_endstop(mcu_endstop, self.name)
# 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_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(),))
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',
'second_homing_speed'])(
self.homing_speed, self.position_endstop,
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.steppers.append(stepper)
self.step_itersolve = self.step_multi_itersolve
mcu_endstop = self.endstops[0][0]
endstop_pin = config.get('endstop_pin', None)
if endstop_pin is not None:
printer = config.get_printer()
ppins = printer.lookup_object('pins')
mcu_endstop = ppins.setup_pin('endstop', endstop_pin)
name = stepper.get_name(short=True)
self.endstops.append((mcu_endstop, name))
query_endstops = printer.try_load_module(config, 'query_endstops')
query_endstops.register_endstop(mcu_endstop, name)
stepper.add_to_endstop(mcu_endstop)
def add_to_endstop(self, mcu_endstop):
for stepper in self.steppers:
stepper.add_to_endstop(mcu_endstop)
def step_multi_itersolve(self, cmove):
for stepper in self.steppers:
stepper.step_itersolve(cmove)
def setup_itersolve(self, alloc_func, *params):
for stepper in self.steppers:
stepper.setup_itersolve(alloc_func, *params)
def set_max_jerk(self, max_halt_velocity, max_accel):
for stepper in self.steppers:
stepper.set_max_jerk(max_halt_velocity, max_accel)
def set_commanded_position(self, pos):
for stepper in self.steppers:
stepper.set_commanded_position(pos)
def set_position(self, coord):
for stepper in self.steppers:
stepper.set_position(coord)
def motor_enable(self, print_time, enable=0):
for stepper in self.steppers:
stepper.motor_enable(print_time, enable)
# 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