neopixel.py

# SPDX-FileCopyrightText: 2016 Damien P. George
# SPDX-FileCopyrightText: 2017 Scott Shawcroft for Adafruit Industries
# SPDX-FileCopyrightText: 2019 Carter Nelson
# SPDX-FileCopyrightText: 2019 Roy Hooper
#
# SPDX-License-Identifier: MIT

"""
`neopixel` - NeoPixel strip driver
====================================================

* Author(s): Damien P. George, Scott Shawcroft, Carter Nelson, Rose Hooper
"""

import sys
import board
import digitalio
from neopixel_write import neopixel_write

import adafruit_pixelbuf

try:
    # Used only for typing
    from typing import Optional, Type
    from types import TracebackType
    import microcontroller
except ImportError:
    pass


__version__ = "0.0.0+auto.0"
__repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_NeoPixel.git"


# Pixel color order constants
RGB = "RGB"
"""Red Green Blue"""
GRB = "GRB"
"""Green Red Blue"""
RGBW = "RGBW"
"""Red Green Blue White"""
GRBW = "GRBW"
"""Green Red Blue White"""


class NeoPixel(adafruit_pixelbuf.PixelBuf):
    """
    A sequence of neopixels.

    :param ~microcontroller.Pin pin: The pin to output neopixel data on.
    :param int n: The number of neopixels in the chain
    :param int bpp: Bytes per pixel. 3 for RGB and 4 for RGBW pixels.
    :param float brightness: Brightness of the pixels between 0.0 and 1.0 where 1.0 is full
      brightness
    :param bool auto_write: True if the neopixels should immediately change when set. If False,
      `show` must be called explicitly.
    :param str pixel_order: Set the pixel color channel order. The default is GRB if bpp is set
      to 3, otherwise GRBW is used as the default.

    Example for Circuit Playground Express:

    .. code-block:: python

        import neopixel
        from board import *

        RED = 0x100000 # (0x10, 0, 0) also works

        pixels = neopixel.NeoPixel(NEOPIXEL, 10)
        for i in range(len(pixels)):
            pixels[i] = RED

    Example for Circuit Playground Express setting every other pixel red using a slice:

    .. code-block:: python

        import neopixel
        from board import *
        import time

        RED = 0x100000 # (0x10, 0, 0) also works

        # Using ``with`` ensures pixels are cleared after we're done.
        with neopixel.NeoPixel(NEOPIXEL, 10) as pixels:
            pixels[::2] = [RED] * (len(pixels) // 2)
            time.sleep(2)

    .. py:method:: NeoPixel.show()

        Shows the new colors on the pixels themselves if they haven't already
        been autowritten.

        The colors may or may not be showing after this function returns because
        it may be done asynchronously.

    .. py:method:: NeoPixel.fill(color)

        Colors all pixels the given ***color***.

    .. py:attribute:: brightness

        Overall brightness of the pixel (0 to 1.0)

    """

    def __init__(
        self,
        pin: microcontroller.Pin,
        n: int,
        *,
        bpp: int = 3,
        brightness: float = 1.0,
        auto_write: bool = True,
        pixel_order: str = None
    ):
        if not pixel_order:
            pixel_order = GRB if bpp == 3 else GRBW
        elif isinstance(pixel_order, tuple):
            order_list = [RGBW[order] for order in pixel_order]
            pixel_order = "".join(order_list)

        self._power = None
        if (
            sys.implementation.version[0] >= 7
            and getattr(board, "NEOPIXEL", None) == pin
        ):
            power = getattr(board, "NEOPIXEL_POWER_INVERTED", None)
            polarity = power is None
            if not power:
                power = getattr(board, "NEOPIXEL_POWER", None)
            if power:
                try:
                    self._power = digitalio.DigitalInOut(power)
                    self._power.switch_to_output(value=polarity)
                except ValueError:
                    pass

        super().__init__(
            n, brightness=brightness, byteorder=pixel_order, auto_write=auto_write
        )

        self.pin = digitalio.DigitalInOut(pin)
        self.pin.direction = digitalio.Direction.OUTPUT

    def deinit(self) -> None:
        """Blank out the NeoPixels and release the pin."""
        self.fill(0)
        self.show()
        self.pin.deinit()
        if self._power:
            self._power.deinit()

    def __enter__(self):
        return self

    def __exit__(
        self,
        exception_type: Optional[Type[BaseException]],
        exception_value: Optional[BaseException],
        traceback: Optional[TracebackType],
    ):
        self.deinit()

    def __repr__(self):
        return "[" + ", ".join([str(x) for x in self]) + "]"

    @property
    def n(self) -> int:
        """
        The number of neopixels in the chain (read-only)
        """
        return len(self)

    def write(self) -> None:
        """.. deprecated: 1.0.0

        Use ``show`` instead. It matches Micro:Bit and Arduino APIs."""
        self.show()

    def _transmit(self, buffer: bytearray) -> None:
        neopixel_write(self.pin, buffer)