Source code for blinkt

import atexit

import RPi.GPIO as GPIO


__version__ = '0.1.0'

DAT = 23
CLK = 24
NUM_PIXELS = 8
BRIGHTNESS = 7

pixels = [[0,0,0,BRIGHTNESS]] * 8

_gpio_setup = False
_clear_on_exit = True

def _exit():
    if _clear_on_exit:
        clear()
        show()
    GPIO.cleanup()

[docs]def set_brightness(brightness): """Set the brightness of all pixels :param brightness: Brightness: 0.0 to 1.0 """ if brightness < 0 or brightness > 1: raise ValueError("Brightness should be between 0.0 and 1.0") for x in range(NUM_PIXELS): pixels[x][3] = int(31.0 * brightness) & 0b11111
[docs]def clear(): """Clear the pixel buffer""" for x in range(NUM_PIXELS): pixels[x][0:3] = [0,0,0]
def _write_byte(byte): for x in range(8): GPIO.output(DAT, byte & 0b10000000) GPIO.output(CLK, 1) byte <<= 1 GPIO.output(CLK, 0) # Emit exactly enough clock pulses to latch the small dark die APA102s which are weird # for some reason it takes 36 clocks, the other IC takes just 4 (number of pixels/2) def _eof(): GPIO.output(DAT, 0) for x in range(36): GPIO.output(CLK, 1) GPIO.output(CLK, 0) def _sof(): GPIO.output(DAT,0) for x in range(32): GPIO.output(CLK, 1) GPIO.output(CLK, 0)
[docs]def show(): """Output the buffer to Blinkt!""" global _gpio_setup if not _gpio_setup: GPIO.setmode(GPIO.BCM) GPIO.setwarnings(False) GPIO.setup([DAT,CLK],GPIO.OUT) _gpio_setup = True _sof() for pixel in pixels: r, g, b, brightness = pixel _write_byte(0b11100000 | brightness) _write_byte(b) _write_byte(g) _write_byte(r) _eof()
[docs]def set_all(r, g, b, brightness=None): """Set the RGB value and optionally brightness of all pixels If you don't supply a brightness value, the last value set for each pixel be kept. :param r: Amount of red: 0 to 255 :param g: Amount of green: 0 to 255 :param b: Amount of blue: 0 to 255 :param brightness: Brightness: 0.0 to 1.0 (default around 0.2) """ for x in range(NUM_PIXELS): set_pixel(x, r, g, b, brightness)
[docs]def set_pixel(x, r, g, b, brightness=None): """Set the RGB value, and optionally brightness, of a single pixel If you don't supply a brightness value, the last value will be kept. :param x: The horizontal position of the pixel: 0 to 7 :param r: Amount of red: 0 to 255 :param g: Amount of green: 0 to 255 :param b: Amount of blue: 0 to 255 :param brightness: Brightness: 0.0 to 1.0 (default around 0.2) """ if brightness is None: brightness = pixels[x][3] else: brightness = int(31.0 * brightness) & 0b11111 pixels[x] = [int(r) & 0xff,int(g) & 0xff,int(b) & 0xff,brightness]
[docs]def set_clear_on_exit(value=True): """Set whether Blinkt! should be cleared upon exit By default Blinkt! will turn off the pixels on exit, but calling:: blinkt.set_clear_on_exit(False) Will ensure that it does not. :param value: True or False (default True) """ global _clear_on_exit _clear_on_exit = value
atexit.register(_exit)