77 lines
3.5 KiB
Python
77 lines
3.5 KiB
Python
# Support for servos
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#
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# Copyright (C) 2017,2018 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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SERVO_SIGNAL_PERIOD = 0.020
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PIN_MIN_TIME = 0.100
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class PrinterServo:
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def __init__(self, config):
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self.printer = config.get_printer()
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ppins = self.printer.lookup_object('pins')
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self.mcu_servo = ppins.setup_pin('pwm', config.get('pin'))
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self.mcu_servo.setup_max_duration(0.)
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self.mcu_servo.setup_cycle_time(SERVO_SIGNAL_PERIOD)
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self.min_width = config.getfloat(
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'minimum_pulse_width', .001, above=0., below=SERVO_SIGNAL_PERIOD)
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self.max_width = config.getfloat(
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'maximum_pulse_width', .002
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, above=self.min_width, below=SERVO_SIGNAL_PERIOD)
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self.max_angle = config.getfloat('maximum_servo_angle', 180.)
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self.angle_to_width = (self.max_width - self.min_width) / self.max_angle
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self.width_to_value = 1. / SERVO_SIGNAL_PERIOD
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self.last_value = self.last_value_time = 0.
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servo_name = config.get_name().split()[1]
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self.gcode = self.printer.lookup_object('gcode')
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self.gcode.register_mux_command("SET_SERVO", "SERVO", servo_name,
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self.cmd_SET_SERVO,
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desc=self.cmd_SET_SERVO_help)
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# Check to see if an initial angle or pulse width is
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# configured and set it as required
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self.initial_pwm_value = None
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initial_angle = config.getfloat('initial_angle', None,
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minval=0., maxval=360.)
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if initial_angle is not None:
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self.initial_pwm_value = self._get_pwm_from_angle(initial_angle)
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else:
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initial_pulse_width = config.getfloat('initial_pulse_width', None,
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minval=self.min_width,
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maxval=self.max_width)
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if initial_pulse_width is not None:
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self.initial_pwm_value = self._get_pwm_from_pulse_width(
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initial_pulse_width)
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def printer_state(self, state):
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if state == 'ready':
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if self.initial_pwm_value is not None:
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toolhead = self.printer.lookup_object('toolhead')
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print_time = toolhead.get_last_move_time()
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self._set_pwm(print_time, self.initial_pwm_value)
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def _set_pwm(self, print_time, value):
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if value == self.last_value:
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return
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print_time = max(print_time, self.last_value_time + PIN_MIN_TIME)
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self.mcu_servo.set_pwm(print_time, value)
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self.last_value = value
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self.last_value_time = print_time
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def _get_pwm_from_angle(self, angle):
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angle = max(0., min(self.max_angle, angle))
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width = self.min_width + angle * self.angle_to_width
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return width * self.width_to_value
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def _get_pwm_from_pulse_width(self, width):
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width = max(self.min_width, min(self.max_width, width))
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return width * self.width_to_value
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cmd_SET_SERVO_help = "Set servo angle"
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def cmd_SET_SERVO(self, params):
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print_time = self.printer.lookup_object('toolhead').get_last_move_time()
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if 'WIDTH' in params:
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self._set_pwm(print_time, self._get_pwm_from_pulse_width(
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self.gcode.get_float('WIDTH', params)))
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else:
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self._set_pwm(print_time, self._get_pwm_from_angle(
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self.gcode.get_float('ANGLE', params)))
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def load_config_prefix(config):
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return PrinterServo(config)
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