Add adafruit servokit compatible pololu library
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# SPDX-FileCopyrightText: 2018 Kattni Rembor for Adafruit Industries
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#
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# SPDX-License-Identifier: MIT
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#
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# MODIFIED to use pololu motor drivers, but compatible with adafruit_servokit driver layout
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# by Cole Deck
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"""
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`adafruit_servokit`
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====================================================
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CircuitPython helper library for the PWM/Servo FeatherWing, Shield and Pi HAT and Bonnet kits.
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* Author(s): Kattni Rembor
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Implementation Notes
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--------------------
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**Hardware:**
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* `8-Channel PWM or Servo FeatherWing <https://www.adafruit.com/product/2928>`_
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* `Adafruit 16-Channel 12-bit PWM/Servo Shield <https://www.adafruit.com/product/1411>`_
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* `Adafruit 16-Channel PWM/Servo HAT for Raspberry Pi <https://www.adafruit.com/product/2327>`_
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* `Adafruit 16-Channel PWM/Servo Bonnet for Raspberry Pi <https://www.adafruit.com/product/3416>`_
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**Software and Dependencies:**
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* Adafruit CircuitPython firmware for the supported boards:
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https://github.com/adafruit/circuitpython/releases
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* Adafruit's Bus Device library: https://github.com/adafruit/Adafruit_CircuitPython_BusDevice
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* Adafruit's Register library: https://github.com/adafruit/Adafruit_CircuitPython_Register
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* Adafruit's PCA9685 library: https://github.com/adafruit/Adafruit_CircuitPython_PCA9685
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* Adafruit's Motor library: https://github.com/adafruit/Adafruit_CircuitPython_Motor
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"""
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#import board
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#from adafruit_pca9685 import PCA9685
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try:
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from typing import Optional
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import maestro
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#from busio import I2C
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#from adafruit_motor.servo import Servo, ContinuousServo
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except ImportError:
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pass
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__version__ = "0.0.0+auto.0"
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__repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_ServoKit.git"
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pca = None
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class ServoKit:
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"""Class representing an Adafruit PWM/Servo FeatherWing, Shield or Pi HAT and Bonnet kits.
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Automatically uses the I2C bus on a Feather, Metro or Raspberry Pi.
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Initialise the PCA9685 chip at ``address``.
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The internal reference clock is 25MHz but may vary slightly with environmental conditions and
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manufacturing variances. Providing a more precise ``reference_clock_speed`` can improve the
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accuracy of the frequency and duty_cycle computations. See the ``calibration.py`` example in
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the `PCA9685 GitHub repo <https://github.com/adafruit/Adafruit_CircuitPython_PCA9685>`_ for
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how to derive this value by measuring the resulting pulse widths.
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:param int channels: The number of servo channels available. Must be 8 or 16. The FeatherWing
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has 8 channels. The Shield, HAT, and Bonnet have 16 channels.
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:param ~I2C i2c: The I2C bus to use. If not provided, it will use generate the default I2C
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bus singleton ``busio.I2C()`` and use that.
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:param int address: The I2C address of the PCA9685. Default address is ``0x40``.
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:param int reference_clock_speed: The frequency of the internal reference clock in Hertz.
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Default reference clock speed is ``25000000``.
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:param int frequency: The overall PWM frequency of the PCA9685 in Hertz.
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Default frequency is ``50``.
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"""
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def __init__(
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self,
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*,
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channels: int,
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#i2c: Optional[I2C] = None,
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address: str = "/dev/ttyACM0",
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reference_clock_speed: int = 25000000,
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frequency: int = 50 # actually, device ID over serial pololu protocol
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) -> None:
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if channels not in [6, 12, 18, 24]:
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raise ValueError("servo_channels must be 6, 12, 18, 24!")
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self._items = [None] * channels
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self._channels = channels
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#if i2c is None:
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# i2c = board.I2C()
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#self._pca = PCA9685(
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# i2c, address=address, reference_clock_speed=reference_clock_speed
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#)
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#self._pca.frequency = frequency
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global pca
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self._pca = maestro.Controller(ttyStr=address,device=frequency)
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pca = self._pca
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self._servo = _Servo(self)
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@property
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def servo(self) -> "_Servo":
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""":class:`~adafruit_motor.servo.Servo` controls for standard servos.
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This FeatherWing example rotates a servo on channel ``0`` to ``180`` degrees for one second,
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and then returns it to ``0`` degrees.
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.. code-block:: python
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import time
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from adafruit_servokit import ServoKit
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kit = ServoKit(channels=8)
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kit.servo[0].angle = 180
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time.sleep(1)
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kit.servo[0].angle = 0
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"""
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return self._servo
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class _Servo:
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# pylint: disable=protected-access
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def __init__(self, kit: ServoKit) -> None:
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self.kit = kit
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def __getitem__(self, servo_channel: int):
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#import adafruit_motor.servo # pylint: disable=import-outside-toplevel
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num_channels = self.kit._channels
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if servo_channel >= num_channels or servo_channel < 0:
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raise ValueError("servo must be 0-{}!".format(num_channels - 1))
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servo = pololuservo(servo_channel)
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return servo
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raise ValueError("Channel {} is already in use.".format(servo_channel))
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def __len__(self) -> int:
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return len(self.kit._items)
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class pololuservo:
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def __init__(self, ch, actuation_range: int = 180, min_pulse: int = 3000, max_pulse: int = 9000):
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self.ch = ch
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self.actuation_range = actuation_range
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self._min_duty = min_pulse
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self._max_duty = max_pulse
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self._duty_range = max_pulse = min_pulse
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self.duty_cycle = 0
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@property
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def angle(self) -> Optional[float]:
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"""The servo angle in degrees. Must be in the range ``0`` to ``actuation_range``.
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Is None when servo is disabled."""
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if self.fraction is None: # special case for disabled servos
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return None
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return self.actuation_range * self.fraction
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@angle.setter
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def angle(self, new_angle: Optional[int]) -> None:
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if new_angle is None: # disable the servo by sending 0 signal
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self.fraction = None
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return
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if new_angle < 0 or new_angle > self.actuation_range:
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raise ValueError("Angle out of range")
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self.fraction = new_angle / self.actuation_range
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@property
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def fraction(self) -> Optional[float]:
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"""Pulse width expressed as fraction between 0.0 (`min_pulse`) and 1.0 (`max_pulse`).
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For conventional servos, corresponds to the servo position as a fraction
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of the actuation range. Is None when servo is diabled (pulsewidth of 0ms).
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"""
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if self.duty_cycle == 0: # Special case for disabled servos
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return None
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return (self.duty_cycle - self._min_duty) / self._duty_range
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@fraction.setter
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def fraction(self, value: Optional[float]) -> None:
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if value is None:
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#self._pwm_out.duty_cycle = 0 # disable the motor
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return
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if not 0.0 <= value <= 1.0:
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raise ValueError("Must be 0.0 to 1.0")
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self.duty_cycle = self._min_duty + int(value * self._duty_range)
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#print(self.ch)
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pca.setTarget(self.ch,self.duty_cycle)
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#self._pwm_out.duty_cycle = duty_cycle
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@ -1 +1,2 @@
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pyserial
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numpy
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