Once you've finished setting up your Feather M4 Express with CircuitPython, you can add these libraries to the lib folder:

  • adafruit_led_animation
  • adafruit_pypixelbuf.mpy
  • neopixel.mpy

Then, you can click on the Download: Project Zip link below to download the code.

import time
import random
import board
import neopixel
import digitalio
import adafruit_led_animation.color as color

#  button pin setup
button = digitalio.DigitalInOut(board.D5)
button.direction = digitalio.Direction.INPUT
button.pull = digitalio.Pull.UP

#  neopixel setup
pixel_pin = board.D6
num_pixels = 61

pixels = neopixel.NeoPixel(pixel_pin, num_pixels, brightness=0.2, auto_write=False)

#  wheel and rainbow_cycle setup
def wheel(pos):
    if pos < 0 or pos > 255:
        return (0, 0, 0)
    if pos < 85:
        return (255 - pos * 3, pos * 3, 0)
    if pos < 170:
        pos -= 85
        return (0, 255 - pos * 3, pos * 3)
    pos -= 170
    return (pos * 3, 0, 255 - pos * 3)

def rainbow_cycle(wait):
    for j in range(255):
        for i in range(num_pixels):
            rc_index = (i * 256 // 10) + j
            pixels[i] = wheel(rc_index & 255)
        pixels.show()
        time.sleep(wait)

#  color_chase setup
def color_chase(c, wait):
    for i in range(num_pixels):
        pixels[i] = c
        time.sleep(wait)
        pixels.show()
    time.sleep(0.5)

#  function to blink the neopixels when you lose
def game_over():
    color_chase(color.BLACK, 0.05)
    pixels.fill(color.RED)
    pixels.show()
    time.sleep(0.5)
    pixels.fill(color.BLACK)
    pixels.show()
    time.sleep(0.5)
    pixels.fill(color.RED)
    pixels.show()
    time.sleep(0.5)
    pixels.fill(color.BLACK)
    pixels.show()
    time.sleep(0.5)
    pixels.fill(color.RED)
    pixels.show()
    time.sleep(1)

#  variables and states
pixel = 0
num = 0
last_num = 0
now_color = 0
next_color = 1
speed = 0.1
level = 0.005
final_level = 0.001
new_target = True
button_state = False

#  neopixel colors
colors = [color.RED, color.ORANGE, color.YELLOW, color.GREEN, color.TEAL, color.CYAN,
          color.BLUE, color.PURPLE, color.MAGENTA, color.GOLD, color.AQUA, color.PINK]

while True:

    #  button debouncing
    if not button.value and not button_state:
        button_state = True

    #  if new level starting..
    if new_target:
        #  randomize target location
        y = int(random.randint(5, 55))
        x = int(y - 1)
        z = int(y + 1)
        new_target = False
        print(x, y, z)
    pixels[x] = color.WHITE
    pixels[y] = colors[next_color]
    pixels[z] = color.WHITE
    #  delay without time.sleep()
    if (pixel + speed) < time.monotonic():
        #  turn off pixel behind chaser
        if num > 0:
            last_num = num - 1
            pixels[last_num] = color.BLACK
            pixels.show()
        #  keep target pixels their colors when the chaser passes
        if last_num in (x, y, z):
            pixels[x] = color.WHITE
            pixels[y] = colors[next_color]
            pixels[z] = color.WHITE
        #  move chaser pixel by one
        if num < num_pixels:
            pixels[num] = colors[now_color]
            pixels.show()
            #print(num)
            #print("target is", y)
            num += 1
        #  send chaser back to the beginning of the circle
        if num == num_pixels:
            last_num = num - 1
            pixels[last_num] = color.BLACK
            pixels.show()
            num = 0
        #  if the chaser hits the target...
        if last_num in [x, y, z] and not button.value:
            button_state = False
            #  fills with the next color
            pixels.fill(colors[next_color])
            pixels.show()
            print(num)
            print(x, y, z)
            #  chaser resets
            num = 0
            time.sleep(0.5)
            pixels.fill(color.BLACK)
            pixels.show()
            #  speed increases for next level
            speed = speed - level
            #  color updates
            next_color = next_color + 1
            if next_color > 11:
                next_color = 0
            now_color = now_color + 1
            if now_color > 11:
                now_color = 0
            #  setup for new target
            new_target = True
            print("speed is", speed)
            print("button is", button.value)
        #  if the chaser misses the target...
        if last_num not in [x, y, z] and not button.value:
            button_state = False
            print(num)
            print(x, y, z)
            #  fills with current chaser color
            pixels.fill(colors[now_color])
            pixels.show()
            #  function to flash all pixels red
            game_over()
            #  chaser is reset
            num = 0
            pixels.fill(color.BLACK)
            pixels.show()
            #  speed is reset to default
            speed = 0.1
            #  colors are reset
            next_color = 1
            now_color = 0
            #  setup for new target
            new_target = True
            print("speed is", speed)
            print("button is", button.value)
        #  when you have beaten all the levels...
        if speed < final_level:
            #  rainbows!
            rainbow_cycle(0.01)
            time.sleep(1)
            #  chaser is reset
            num = 0
            pixels.fill(color.BLACK)
            pixels.show()
            #  speed is reset to default
            speed = 0.1
            #  colors are reset
            next_color = 1
            now_color = 0
            #  setup for new target
            new_target = True
        #  time.monotonic() is reset for the delay
        pixel = time.monotonic()

Your Feather M4 Express CIRCUITPY drive should look like this after you load the libraries and code.py file:

This guide was first published on Jul 28, 2020. It was last updated on Jul 28, 2020.
This page (Coding the Pixel Chase Game) was last updated on Oct 21, 2020.