106 lines
4.9 KiB
Python
106 lines
4.9 KiB
Python
# Support for servos
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#
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# Copyright (C) 2017-2024 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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from . import output_pin
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SERVO_SIGNAL_PERIOD = 0.020
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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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self.min_width = config.getfloat('minimum_pulse_width', .001,
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above=0., below=SERVO_SIGNAL_PERIOD)
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self.max_width = config.getfloat('maximum_pulse_width', .002,
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above=self.min_width,
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below=SERVO_SIGNAL_PERIOD)
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self.max_angle = config.getfloat('maximum_servo_angle', 180.)
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self.signal_duration = config.getfloat('signal_duration', 0, minval=0.)
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if self.signal_duration:
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self.signal_duration = max(self.signal_duration, SERVO_SIGNAL_PERIOD)
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if abs(self.signal_duration / SERVO_SIGNAL_PERIOD - round(self.signal_duration / SERVO_SIGNAL_PERIOD)) < 1e-9:
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self.signal_duration -= 0.001
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self.steps_decomposed = config.getint('steps_decomposed', 0)
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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 = 0.
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self.initial_pwm = 0.
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iangle = config.getfloat('initial_angle', None, minval=0., maxval=360.)
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if iangle is not None:
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self.initial_pwm = self._get_pwm_from_angle(iangle)
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else:
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iwidth = config.getfloat('initial_pulse_width', 0.,
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minval=0., maxval=self.max_width)
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self.initial_pwm = self._get_pwm_from_pulse_width(iwidth)
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# Setup mcu_servo pin
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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.mcu_servo.setup_start_value(self.initial_pwm, 0.)
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# Register event handler
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self.printer.register_event_handler("klippy:ready", self._handle_ready)
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# Create gcode request queue
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self.gcrq = output_pin.GCodeRequestQueue(
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config, self.mcu_servo.get_mcu(), self.__set_pwm)
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# Register commands
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servo_name = config.get_name().split()[1]
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gcode = self.printer.lookup_object('gcode')
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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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def get_status(self, eventtime):
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return {'value': self.last_value}
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def __set_pwm(self, print_time, value):
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if self.steps_decomposed:
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return self._set_low_pwm(print_time, value)
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else:
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return self._set_pwm(print_time, 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 "discard", 0.
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self.last_value = value
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self.mcu_servo.set_pwm(print_time, value)
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if self.signal_duration:
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self.mcu_servo.set_pwm(print_time + self.signal_duration, 0)
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def _get_s_curve_value(self, last_value, value, t):
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smooth_factor = t * t * (3 - 2 * t)
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return last_value + smooth_factor * (value - last_value)
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def _set_low_pwm(self, print_time, value):
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if value == self.last_value:
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return "discard", 0.
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enter_value = self.initial_pwm if self.last_value == 0 else self.last_value
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self.last_value = value
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steps = self.steps_decomposed
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for step in range(steps):
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t = step / (steps - 1)
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current_value = self._get_s_curve_value(enter_value, value, t)
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next_time = print_time + SERVO_SIGNAL_PERIOD * step
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self.mcu_servo.set_pwm(next_time, current_value)
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if self.signal_duration:
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next_time = print_time + SERVO_SIGNAL_PERIOD * steps + self.signal_duration
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self.mcu_servo.set_pwm(next_time, 0)
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def _handle_ready(self):
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self.gcrq.queue_gcode_request(self.initial_pwm)
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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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if 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, gcmd):
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width = gcmd.get_float('WIDTH', None)
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if width is not None:
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value = self._get_pwm_from_pulse_width(width)
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else:
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angle = gcmd.get_float('ANGLE')
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value = self._get_pwm_from_angle(angle)
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self.gcrq.queue_gcode_request(value)
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def load_config_prefix(config):
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return PrinterServo(config)
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