Once your Feather M4 Express is set up with CircuitPython 6.0.0-alpha.1 or greater, you'll also need to add some libraries. Follow this page for information on how to download and add libraries to your Feather.

From the library bundle you downloaded in that guide page, transfer the following libraries onto the Feather's /lib directory:

  • adafruit_bus_device
  • adafruit_led_animation
  • adafruit_lis3dh_animation
  • neopixel.mpy

Text Editor

Adafruit recommends using the Mu editor for using your CircuitPython code with the Feather boards. You can get more info in this guide.

Alternatively, you can use any text editor that saves files.

Audio Samples

You can get started by using the Lucio music and sound effects .mp3 files. (Of course, you're free to use any files that you like, see below for more info on that.)

Download the .zip file linked below and then uncompress the file. Drag the /lucio directory onto the root level of your Feather's CIRCUITPY drive.

Make Your Own

To make your own .mp3, use audio software such as Audacity to save them with these settings:

  • bit rate: anywhere from 16 to 320 kb/s (lower will be smaller, higher is better quality)
  • sample rate: 22050Hz or 44100Hz are recommended, although 16kHz, 24kHz, and 48kHz should also work
  • channels: mono or stereo
  • must be DRM free

Copy the code below and paste it into Mu. Then, save it to your Feather as

# Lucio 2020
# Feather M4 + Propmaker + amps + lots of neopixels
import board
import busio
from digitalio import DigitalInOut, Direction, Pull
import audioio
import audiomixer
import audiomp3
import adafruit_lis3dh
import neopixel
from adafruit_led_animation.animation.solid import Solid
from adafruit_led_animation.animation.comet import Comet
from adafruit_led_animation.animation.pulse import Pulse
from adafruit_led_animation.helper import PixelSubset
from import AnimationGroup
from adafruit_led_animation.color import RED, ORANGE, WHITE

ORANGE_DIM = 0x801400  # half value version
RED_DIM = 0x800000

#  ---Set Volume Max Here---
VOLUME_MULT = 0.65  # 1 = full volume, 0.1 is very quiet, 0 is muted

mode_switch = DigitalInOut(board.D9)
mode_state = mode_switch.value
trig_button = DigitalInOut(board.A4)
alt_button = DigitalInOut(board.A5)

# Set up accelerometer on I2C bus, 4G range:
i2c = busio.I2C(board.SCL, board.SDA)
int1 = DigitalInOut(board.D6)
accel = adafruit_lis3dh.LIS3DH_I2C(i2c, int1=int1)

enable = DigitalInOut(board.D10)
enable.direction = Direction.OUTPUT
enable.value = True
# Set up speakers and mixer. Stereo files, where music has empty right channel, FX empty left
speaker = audioio.AudioOut(board.A0, right_channel=board.A1)
mixer = audiomixer.Mixer(channel_count=2, buffer_size=2304, sample_rate=22050)

pixel_pin = board.D5
pixel_num = 154
pixels = neopixel.NeoPixel(
    pixel_pin, pixel_num, brightness=0.6, auto_write=False, pixel_order=neopixel.GRBW
# ^ change pixel_order depending on RGB vs. RGBW pixels

#  ---Pixel Map---
#  this is the physical order in which the strips are plugged
pixel_stripA = PixelSubset(pixels, 0, 18)  # 18 pixel strip
pixel_stripB = PixelSubset(pixels, 18, 36)  # 18 pixel strip
pixel_jewel = PixelSubset(pixels, 36, 43)  # 7 pixel jewel
pixel_ringsAll = PixelSubset(pixels, 43, 151)  # all of the rings
#  or use rings individually:
# pixel_ringA = PixelSubset(pixels, 43, 59)  # 16 pixel ring
# pixel_ringB = PixelSubset(pixels, 59, 75)  # 16 pixel ring
# pixel_ringC = PixelSubset(pixels, 75, 91)  # 16 pixel ring
# pixel_ringD = PixelSubset(pixels, 91, 151)  # 60 pixel ring

#  ---BPM---
BPM = 128
BEAT = 60 / BPM  # quarter note beat
b16TH = BEAT / 4  # 16TH note
b64TH = BEAT / 16  # sixty-fourth

#  ---Anim Setup---
# heal color mode
# Pulse 'speed' = smoothness
pulse_rings_m0 = Pulse(pixel_ringsAll, speed=0.01, color=ORANGE, period=BEAT)
pulse_jewel_m0 = Pulse(pixel_jewel, speed=0.01, color=ORANGE, period=BEAT)
comet_stripA_m0 = Comet(
    pixel_stripA, speed=b64TH, color=ORANGE, tail_length=9, bounce=False
comet_stripB_m0 = Comet(
    pixel_stripB, speed=b64TH, color=ORANGE, tail_length=9, bounce=False

# speed color mode
pulse_rings_m1 = Pulse(pixel_ringsAll, speed=0.02, color=RED, period=BEAT / 2)
pulse_jewel_m1 = Pulse(pixel_jewel, speed=0.02, color=RED, period=BEAT / 2)
comet_stripA_m1 = Comet(
    pixel_stripA, speed=b64TH, color=RED, tail_length=9, bounce=False
comet_stripB_m1 = Comet(
    pixel_stripB, speed=b64TH, color=RED, tail_length=9, bounce=False

solid_white = Solid(pixel_ringsAll, color=WHITE)

# ---Anim Modes---
vu_strip_animations_mode0 = AnimationGroup(comet_stripA_m0, comet_stripB_m0, sync=True)
vu_strip_animations_mode1 = AnimationGroup(comet_stripA_m1, comet_stripB_m1, sync=True)

#  ---Audio Setup---
if mode_state:
    BGM = "/lucio/bgmheal.mp3"
    BGM = "/lucio/bgmspeed.mp3"
sample0 = audiomp3.MP3Decoder(open(BGM, "rb"))
FX = "/lucio/shoot.mp3"
sample1 = audiomp3.MP3Decoder(open(FX, "rb"))
mixer.voice[0].play(sample0, loop=True)
mixer.voice[0].level = 0.3 * VOLUME_MULT
mixer.voice[1].level = 0.7 * VOLUME_MULT

while True:
    if mode_state:  # heal mode on startup
    else:  # speed mode on startup

    # Change modes
    if mode_switch.value:
        if mode_state == 0:  # state has changed, toggle it
            BGM = "/lucio/bgmheal.mp3"
            sample0.file = open(BGM, "rb")
            mixer.voice[0].play(sample0, loop=True)
            mode_state = 1
        if mode_state == 1:
            BGM = "/lucio/bgmspeed.mp3"
            sample0.file = open(BGM, "rb")
            mixer.voice[0].play(sample0, loop=True)
            mode_state = 0

    x, _, _ = accel.acceleration  # get accelerometer values

    if not mixer.voice[1].playing:
        if not trig_button.value:  # trigger squeezed
            FX_sample = "/lucio/shoot.mp3"
            sample1.file = open(FX_sample, "rb")
            if mode_state:

        if not alt_button.value:  # alt trigger squeezed
            FX_sample = "/lucio/alt_shoot.mp3"
            sample1.file = open(FX_sample, "rb")
            if mode_state:

        if accel.acceleration.x > 8:  # reload
            FX_sample = "/lucio/reload.mp3"
            sample1.file = open(FX_sample, "rb")
            if mode_state:

        if accel.acceleration.x < -8:  # Ultimate
            FX_sample = "/lucio/ultimate.mp3"
            sample1.file = open(FX_sample, "rb")
            if mode_state:

What It Does

These are the main features of the code:

  • Play one of two background music song files depending on the mode switch position
  • Play NeoPixel LED animation to the beat, the base color changed depending on mode switch position
  • Trigger button plays shooting sound effect file and flashes all NeoPixels white
  • Alt trigger button plays alt shooting sound effect file and flashes all NeoPixels white
  • Tilt "up" of the unit (Propmaker FeatherWing's accelerometer) plays reload sound effect
  • Tilt "down" of the unit plays "ultimate" sound effect

Look through the code and you'll see places to tweak and modify the behavior. You can use the led_animation library's PixelSubset code to send entirely different animation and color to the different logical groupings of pixels, for example.

This guide was first published on Jul 08, 2020. It was last updated on Jul 08, 2020.

This page (Code the Blaster) was last updated on Dec 04, 2021.

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