neopixel lantern scratchpad

lantern.py

import machine
import neopixel
import time


def cycle(np):
    n = np.n
    for i in range(4 * n):
        for j in range(n):
            np[j] = (0, 0, 0)
        np[i % n] = (255, 255, 255)
        np.write()
        time.sleep_ms(25)


def bounce_blue(np):
    n = np.n
    for i in range(4 * n):
        for j in range(n):
            np[j] = (0, 0, 128)
        if (i // n) % 2 == 0:
            np[i % n] = (0, 0, 0)
        else:
            np[n - 1 - (i % n)] = (0, 0, 0)
        np.write()
        time.sleep_ms(60)


def fade_red(np):
    n = np.n
    for i in range(0, 4 * 256, 8):
        for j in range(n):
            if (i // 256) % 2 == 0:
                val = i & 0xff
            else:
                val = 255 - (i & 0xff)
            np[j] = (val, 0, 0)
        np.write()


# Turn off all the LEDs
# self explanatory, 0 is off
def clear(np):
    n = np.n
    for i in range(n):
        np[i] = (0, 0, 0)
    np.write()


# Make a nice red-orange glow
def fire(np):
    for i in range(np.n):
        if i % 2 == 0:
            # even LEDs are red
            np[i] = (255, 0, 0)
        else:
            # odd LEDs are orange
            np[i] = (255, 128, 0)
    np.write()


if __name__ == '__main__':
    # Data line is on pin 13
    # and there are 12 LEDs
    np = neopixel.NeoPixel(machine.Pin(13), 12)