# Adafruit NeoPixel library port to the rpi_ws281x library.
# Author: Tony DiCola (tony@tonydicola.com), Jeremy Garff (jer@jers.net)
import _rpi_ws281x as ws
import atexit
class RGBW(int):
def __new__(self, r, g=None, b=None, w=None):
if (g, b, w) == (None, None, None):
return int.__new__(self, r)
else:
if w is None:
w = 0
return int.__new__(self, (w << 24) | (r << 16) | (g << 8) | b)
@property
def r(self):
return (self >> 16) & 0xff
@property
def g(self):
return (self >> 8) & 0xff
@property
def b(self):
return (self) & 0xff
@property
def w(self):
return (self >> 24) & 0xff
[docs]
def Color(red, green, blue, white=0):
"""Convert the provided red, green, blue color to a 24-bit color value.
Each color component should be a value 0-255 where 0 is the lowest intensity
and 255 is the highest intensity.
"""
return RGBW(red, green, blue, white)
[docs]
class PixelStrip:
[docs]
def __init__(self, num, pin, freq_hz=800000, dma=10, invert=False,
brightness=255, channel=0, strip_type=None, gamma=None):
"""Class to represent a SK6812/WS281x LED display. Num should be the
number of pixels in the display, and pin should be the GPIO pin connected
to the display signal line (must be a PWM pin like 18!). Optional
parameters are freq, the frequency of the display signal in hertz (default
800khz), dma, the DMA channel to use (default 10), invert, a boolean
specifying if the signal line should be inverted (default False), and
channel, the PWM channel to use (defaults to 0).
"""
if gamma is None:
# Support gamma in place of strip_type for back-compat with
# previous version of forked library
if type(strip_type) is list and len(strip_type) == 256:
gamma = strip_type
strip_type = None
else:
gamma = list(range(256))
if strip_type is None:
strip_type = ws.WS2811_STRIP_GRB
# Create ws2811_t structure and fill in parameters.
self._leds = ws.new_ws2811_t()
# Initialize the channels to zero
for channum in range(2):
chan = ws.ws2811_channel_get(self._leds, channum)
ws.ws2811_channel_t_count_set(chan, 0)
ws.ws2811_channel_t_gpionum_set(chan, 0)
ws.ws2811_channel_t_invert_set(chan, 0)
ws.ws2811_channel_t_brightness_set(chan, 0)
# Initialize the channel in use
self._channel = ws.ws2811_channel_get(self._leds, channel)
ws.ws2811_channel_t_gamma_set(self._channel, gamma)
ws.ws2811_channel_t_count_set(self._channel, num)
ws.ws2811_channel_t_gpionum_set(self._channel, pin)
ws.ws2811_channel_t_invert_set(self._channel, 0 if not invert else 1)
ws.ws2811_channel_t_brightness_set(self._channel, brightness)
ws.ws2811_channel_t_strip_type_set(self._channel, strip_type)
# Initialize the controller
ws.ws2811_t_freq_set(self._leds, freq_hz)
ws.ws2811_t_dmanum_set(self._leds, dma)
self.size = num
# Substitute for __del__, traps an exit condition and cleans up properly
atexit.register(self._cleanup)
[docs]
def __getitem__(self, pos):
"""Return the 24-bit RGB color value at the provided position or slice
of positions.
"""
# Handle if a slice of positions are passed in by grabbing all the values
# and returning them in a list.
if isinstance(pos, slice):
return [ws.ws2811_led_get(self._channel, n) for n in range(*pos.indices(self.size))]
# Else assume the passed in value is a number to the position.
else:
return ws.ws2811_led_get(self._channel, pos)
[docs]
def __setitem__(self, pos, value):
"""Set the 24-bit RGB color value at the provided position or slice of
positions.
"""
# Handle if a slice of positions are passed in by setting the appropriate
# LED data values to the provided value.
if isinstance(pos, slice):
for n in range(*pos.indices(self.size)):
ws.ws2811_led_set(self._channel, n, value)
# Else assume the passed in value is a number to the position.
else:
return ws.ws2811_led_set(self._channel, pos, value)
def __len__(self):
return ws.ws2811_channel_t_count_get(self._channel)
def _cleanup(self):
# Clean up memory used by the library when not needed anymore.
if self._leds is not None:
ws.ws2811_fini(self._leds)
ws.delete_ws2811_t(self._leds)
self._leds = None
self._channel = None
def setGamma(self, gamma):
if type(gamma) is list and len(gamma) == 256:
ws.ws2811_channel_t_gamma_set(self._channel, gamma)
[docs]
def begin(self):
"""Initialize library, must be called once before other functions are
called.
"""
resp = ws.ws2811_init(self._leds)
if resp != 0:
str_resp = ws.ws2811_get_return_t_str(resp)
raise RuntimeError('ws2811_init failed with code {0} ({1})'.format(resp, str_resp))
[docs]
def show(self):
"""Update the display with the data from the LED buffer."""
resp = ws.ws2811_render(self._leds)
if resp != 0:
str_resp = ws.ws2811_get_return_t_str(resp)
raise RuntimeError('ws2811_render failed with code {0} ({1})'.format(resp, str_resp))
[docs]
def setPixelColor(self, n, color):
"""Set LED at position n to the provided 24-bit color value (in RGB order).
"""
self[n] = color
[docs]
def setPixelColorRGB(self, n, red, green, blue, white=0):
"""Set LED at position n to the provided red, green, and blue color.
Each color component should be a value from 0 to 255 (where 0 is the
lowest intensity and 255 is the highest intensity).
"""
self.setPixelColor(n, Color(red, green, blue, white))
def getBrightness(self):
return ws.ws2811_channel_t_brightness_get(self._channel)
[docs]
def setBrightness(self, brightness):
"""Scale each LED in the buffer by the provided brightness. A brightness
of 0 is the darkest and 255 is the brightest.
"""
ws.ws2811_channel_t_brightness_set(self._channel, brightness)
[docs]
def getPixels(self):
"""Return an object which allows access to the LED display data as if
it were a sequence of 24-bit RGB values.
"""
return self[:]
[docs]
def numPixels(self):
"""Return the number of pixels in the display."""
return len(self)
[docs]
def getPixelColor(self, n):
"""Get the 24-bit RGB color value for the LED at position n."""
return self[n]
def getPixelColorRGB(self, n):
return RGBW(self[n])
def getPixelColorRGBW(self, n):
return RGBW(self[n])
# Shim for back-compatibility
class Adafruit_NeoPixel(PixelStrip):
pass