Source code for adafruit_dotstar

# The MIT License (MIT)
#
# Copyright (c) 2016 Damien P. George (original Neopixel object)
# Copyright (c) 2017 Ladyada
# Copyright (c) 2017 Scott Shawcroft for Adafruit Industries
#
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# of this software and associated documentation files (the "Software"), to deal
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# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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"""
`adafruit_dotstar` - DotStar strip driver
====================================================

* Author(s): Damien P. George, Limor Fried & Scott Shawcroft
"""
import math

import busio
import digitalio

__version__ = "0.0.0-auto.0"
__repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_DotStar.git"

START_HEADER_SIZE = 4
LED_START = 0b11100000  # Three "1" bits, followed by 5 brightness bits

# Pixel color order constants
RGB = (0, 1, 2)
RBG = (0, 2, 1)
GRB = (1, 0, 2)
GBR = (1, 2, 0)
BRG = (2, 0, 1)
BGR = (2, 1, 0)


[docs]class DotStar: """ A sequence of dotstars. :param ~microcontroller.Pin clock: The pin to output dotstar clock on. :param ~microcontroller.Pin data: The pin to output dotstar data on. :param int n: The number of dotstars in the chain :param float brightness: Brightness of the pixels between 0.0 and 1.0 :param bool auto_write: True if the dotstars should immediately change when set. If False, `show` must be called explicitly. :param tuple pixel_order: Set the pixel order on the strip - different strips implement this differently. If you send red, and it looks blue or green on the strip, modify this! It should be one of the values above Example for Gemma M0: .. code-block:: python import adafruit_dotstar import time from board import * RED = 0x100000 with adafruit_dotstar.DotStar(APA102_SCK, APA102_MOSI, 1) as pixels: pixels[0] = RED time.sleep(2) """ def __init__(self, clock, data, n, *, brightness=1.0, auto_write=True, pixel_order=BGR): self._spi = None try: self._spi = busio.SPI(clock, MOSI=data) while not self._spi.try_lock(): pass self._spi.configure(baudrate=4000000) except ValueError: self.dpin = digitalio.DigitalInOut(data) self.cpin = digitalio.DigitalInOut(clock) self.dpin.direction = digitalio.Direction.OUTPUT self.cpin.direction = digitalio.Direction.OUTPUT self.cpin.value = False self._n = n # Supply one extra clock cycle for each two pixels in the strip. self.end_header_size = n // 16 if n % 16 != 0: self.end_header_size += 1 self._buf = bytearray(n * 4 + START_HEADER_SIZE + self.end_header_size) self.end_header_index = len(self._buf) - self.end_header_size self.pixel_order = pixel_order # Four empty bytes to start. for i in range(START_HEADER_SIZE): self._buf[i] = 0x00 # Mark the beginnings of each pixel. for i in range(START_HEADER_SIZE, self.end_header_index, 4): self._buf[i] = 0xff # 0xff bytes at the end. for i in range(self.end_header_index, len(self._buf)): self._buf[i] = 0xff self._brightness = 1.0 # Set auto_write to False temporarily so brightness setter does _not_ # call show() while in __init__. self.auto_write = False self.brightness = brightness self.auto_write = auto_write
[docs] def deinit(self): """Blank out the DotStars and release the resources.""" self.auto_write = False for i in range(START_HEADER_SIZE, self.end_header_index): if i % 4 != 0: self._buf[i] = 0 self.show() if self._spi: self._spi.deinit() else: self.dpin.deinit() self.cpin.deinit()
def __enter__(self): return self def __exit__(self, exception_type, exception_value, traceback): self.deinit() def __repr__(self): return "[" + ", ".join([str(x) for x in self]) + "]" def _set_item(self, index, value): """ value can be one of three things: a (r,g,b) list/tuple a (r,g,b, brightness) list/tuple a single, longer int that contains RGB values, like 0xFFFFFF brightness, if specified should be a float 0-1 Set a pixel value. You can set per-pixel brightness here, if it's not passed it will use the max value for pixel brightness value, which is a good default. Important notes about the per-pixel brightness - it's accomplished by PWMing the entire output of the LED, and that PWM is at a much slower clock than the rest of the LEDs. This can cause problems in Persistence of Vision Applications """ offset = index * 4 + START_HEADER_SIZE rgb = value if isinstance(value, int): rgb = (value >> 16, (value >> 8) & 0xff, value & 0xff) if len(value) == 4: brightness = value[-1] rgb = value[:3] else: brightness = 1 # LED startframe is three "1" bits, followed by 5 brightness bits # then 8 bits for each of R, G, and B. The order of those 3 are configurable and # vary based on hardware brightness_byte = math.ceil(brightness * 31) & 0b00011111 self._buf[offset] = brightness_byte | LED_START self._buf[offset + 1] = rgb[self.pixel_order[0]] self._buf[offset + 2] = rgb[self.pixel_order[1]] self._buf[offset + 3] = rgb[self.pixel_order[2]] def __setitem__(self, index, val): if isinstance(index, slice): start, stop, step = index.indices(self._n) length = stop - start if step != 0: length = math.ceil(length / step) if len(val) != length: raise ValueError("Slice and input sequence size do not match.") for val_i, in_i in enumerate(range(start, stop, step)): self._set_item(in_i, val[val_i]) else: self._set_item(index, val) if self.auto_write: self.show() def __getitem__(self, index): if isinstance(index, slice): out = [] for in_i in range(*index.indices(self._n)): out.append( tuple(self._buf[in_i * 4 + (3 - i) + START_HEADER_SIZE] for i in range(3))) return out if index < 0: index += len(self) if index >= self._n or index < 0: raise IndexError offset = index * 4 return tuple(self._buf[offset + (3 - i) + START_HEADER_SIZE] for i in range(3)) def __len__(self): return self._n @property def brightness(self): """Overall brightness of the pixel""" return self._brightness @brightness.setter def brightness(self, brightness): self._brightness = min(max(brightness, 0.0), 1.0) if self.auto_write: self.show()
[docs] def fill(self, color): """Colors all pixels the given ***color***.""" auto_write = self.auto_write self.auto_write = False for i, _ in enumerate(self): self[i] = color if auto_write: self.show() self.auto_write = auto_write
def _ds_writebytes(self, buf): for b in buf: for _ in range(8): self.cpin.value = True self.dpin.value = (b & 0x80) self.cpin.value = False b = b << 1
[docs] def show(self): """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.""" # Create a second output buffer if we need to compute brightness buf = self._buf if self.brightness < 1.0: buf = bytearray(self._buf) # Four empty bytes to start. for i in range(START_HEADER_SIZE): buf[i] = 0x00 for i in range(START_HEADER_SIZE, self.end_header_index): buf[i] = self._buf[i] if i % 4 == 0 else int(self._buf[i] * self._brightness) # Four 0xff bytes at the end. for i in range(self.end_header_index, len(buf)): buf[i] = 0xff if self._spi: self._spi.write(buf) else: self._ds_writebytes(buf) self.cpin.value = False