Adafruit CircuitExpress Fiddling

led_magic.py

from adafruit_circuitplayground.express import cpx
import time

## Constants
# timing settings
SLEEP = 0.001

# light range settings
MIN = 0
MAX = 16

# color ratios
CR = (1.0, 0.0, 0.0)
CO = (1.0, 0.5, 0.0)
CY = (1.0, 1.0, 0.0)
CG = (0.0, 1.0, 0.0)
CB = (0.0, 0.0, 1.0)
CI = (0.3, 0.5, 0.0)
CV = (0.6, 0.0, 0.8)
W1 = (0.1, 0.1, 0.1)
W3 = (0.3, 0.3, 0.3)
W5 = (0.5, 0.5, 0.5)
WX = (1.0, 1.0, 1.0)

## Helper Functions
# scale a color ratio into a final color
def scale(color, val):
    return (
        int(color[0] * val),
        int(color[1] * val),
        int(color[2] * val),
    )

# helper to set colors to happy rainbow, scaled by some value and offset by some number of leds
def set_color(val, offset):
    cpx.pixels[(0 + offset) % 10] = scale(CR, val)
    cpx.pixels[(1 + offset) % 10] = scale(CO, val)
    cpx.pixels[(2 + offset) % 10] = scale(CY, val)
    cpx.pixels[(3 + offset) % 10] = scale(CG, val)
    cpx.pixels[(4 + offset) % 10] = scale(CI, val)
    cpx.pixels[(5 + offset) % 10] = scale(CV, val)
    cpx.pixels[(6 + offset) % 10] = scale(W1, val)
    cpx.pixels[(7 + offset) % 10] = scale(W3, val)
    cpx.pixels[(8 + offset) % 10] = scale(W5, val)
    cpx.pixels[(9 + offset) % 10] = scale(WX, val)
    cpx.pixels.show()

# class to track button presses over time
class Buttons(object):
    def __init__(self):
        self.a = False
        self.b = False
        self.presses = []

    def get_presses(self):
        for press in self.presses:
            yield press
        self.presses = []

    def check_io(self):
        a = cpx.button_a
        b = cpx.button_b

        if not self.a and a:
            self.presses.append('a')
        if not self.b and b:
            self.presses.append('b')
        if cpx.tapped:
            self.presses.append('tap')

        self.a, self.b = a, b

## Initialization of Useful Stuff
butt = Buttons()
cpx.pixels.auto_write = False
cpx.detect_taps = 1

# generator of an infinite see-saw pattern of scale values to "pulse" leds
def see_saw():
    while True:
        for i in range(MIN, MAX):
            yield i
        for i in range(MAX, MIN, -1):
            yield i

## Main logic
def main():
    print("Starting...")

    ofs = 0

    # for an infinite see-saw of patterns
    for i in see_saw():
        # set colors
        set_color(i, ofs)

        # wait
        time.sleep(SLEEP)

        # stop any beep we started
        cpx.stop_tone()

        # check for button presses
        butt.check_io()

        # process all button presses to get new offset
        for press in butt.get_presses():
            if press == 'a':
                # A offsets counter-clockwise
                ofs -= 1
            if press == 'b':
                # B offsets clockwise
                ofs += 1
            if press == 'tap':
                # taps reset offset
                ofs = 0
          
            # cap offset in [0, 9]
            ofs %= 10

            # print changed offset
            print("Offset:", ofs)

            # start a beep whose tone depends on the offset (gets stopped after the sleep above)
            cpx.start_tone(500 + 20 * ofs)

# run code
main()