It's always a good idea to get your software loaded onto your board before the build. That way you'll be able to test your solder joints at each step of the way, and you'll get instant gratification when you plug in the lights.
Getting the software loaded is a 3-step process:
- Install the operating system (CircuitPython) on the board
- Copy the required libraries into the /lib folder on the board
- Save the code.py file to the board
CircuitPython is a fairly new OS that's changing rapidly. New features are being added and bugs are being fixed all the time, so it's always best to get a fresh version of CircuitPython and the library files before coding.
Install CircuitPython
The Adafruit Feather Sense ships with CircuitPython, but let's go ahead and update it to the latest version. It's super easy with the circuitpython.org website. Follow the directions on the Feather Bluefruit Sense guide, or click the button below for a direct download link.
Download the file, plug your Feather Sense into your computer via the USB port, and double-click the reset button. You'll see a drive appear called FTHR840BOOT. Drag the .uf2 file you just downloaded onto this drive to install CircuitPython.
You'll know it worked if the FTHR840BOOT drive name changes to CIRCUITPY.
Adafruit Circuit Python Libraries
Download the CircuitPython library bundle per the Feather Sense guide instructions here. Unzip the files into a folder on your computer. Create a new folder on the CIRCUITPY drive and name it lib.
Open the library download folder and find the following files. Copy them into the lib folder on your CIRCUITPY drive.
- adafruit_bus_device (directory)
- adafruit_lsm6ds.mpy
- adafruit_register (directory)
- neopixel.mpy
Upload Files
Click the link below to download the project zip – This contains the code. Upload the code.py file to the CIRCUITPY drive root (main) folder.
Check out the image above to see what your CIRCUITPY drive should look like when all the files are in place.
# SPDX-FileCopyrightText: 2020 Erin St Blaine for Adafruit Industries
# SPDX-FileCopyrightText: 2020 Limor Fried for Adafruit Industries
#
# SPDX-License-Identifier: MIT
"""
Prop-Maker based LED Bullwhip
Adafruit invests time and resources providing this open source code.
Please support Adafruit and open source hardware by purchasing
products from Adafruit!
Written by Erin St Blaine & Limor Fried for Adafruit Industries
Copyright (c) 2019-2020 Adafruit Industries
Licensed under the MIT license.
All text above must be included in any redistribution.
"""
import time
import array
import math
import digitalio
import audiobusio
import board
import neopixel
i2c = board.I2C() # uses board.SCL and board.SDA
# check for LSM6DS33 or LSM6DS3TR-C
try:
from adafruit_lsm6ds.lsm6ds33 import LSM6DS33 as LSM6DS
sensor = LSM6DS(i2c)
except RuntimeError:
from adafruit_lsm6ds.lsm6ds3trc import LSM6DS3TRC as LSM6DS
sensor = LSM6DS(i2c)
# CUSTOMISE COLORS HERE:
COLOR = (40, 3, 0) # Default idle is blood orange
HIT_COLOR = (0, 250, 0) # hit color is green
LIGHT_WAVE_COLOR = (200, 50, 200) # purple
DARK_COLOR = (0, 0, 0)
CRACK_COLOR = (250, 250, 250) #white
# CUSTOMISE IDLE PULSE SPEED HERE: 0 is fast, above 0 slows down
IDLE_PULSE_SPEED = 0 # Default is 0 seconds
SWING_BLAST_SPEED = 0.007
# CUSTOMISE BRIGHTNESS HERE: must be a number between 0 and 1
IDLE_PULSE_BRIGHTNESS_MIN = 0.1 # Default minimum idle pulse brightness
IDLE_PULSE_BRIGHTNESS_MAX = 0.5 # Default maximum idle pulse brightness
# CUSTOMISE SENSITIVITY HERE: smaller numbers = more sensitive to motion
HIT_THRESHOLD = 1150
SWING_THRESHOLD = 750
SOUND_THRESHOLD = 2000
# Set to the length in seconds for the animations
POWER_ON_DURATION = 1.7
LIGHT_WAVE_DURATION = 1
HIT_DURATION = 2
SWING_DURATION = 0
FADE_DURATION = 1
WHIP_CRACK_DURATION = 0.5
NUM_PIXELS = 60 # Number of pixels used in project
NEOPIXEL_PIN = board.D5
POWER_PIN = board.D10
ONSWITCH_PIN = board.A1
led = digitalio.DigitalInOut(ONSWITCH_PIN)
led.direction = digitalio.Direction.OUTPUT
led.value = True
enable = digitalio.DigitalInOut(POWER_PIN)
enable.direction = digitalio.Direction.OUTPUT
enable.value = False
strip = neopixel.NeoPixel(NEOPIXEL_PIN, NUM_PIXELS, brightness=1, auto_write=False)
strip.fill(0) # NeoPixels off ASAP on startup
strip.show()
WAVE_FILE = None
#Set up mic
mic = audiobusio.PDMIn(board.MICROPHONE_CLOCK,
board.MICROPHONE_DATA,
sample_rate=16000,
bit_depth=16)
COLOR_IDLE = COLOR # 'idle' color is the default
COLOR_HIT = HIT_COLOR # "hit" color is HIT_COLOR set above
COLOR_SWING = LIGHT_WAVE_COLOR # "swing" color is HIT_COLOR set above
COLOR_ACTIVE = LIGHT_WAVE_COLOR
def mean(values):
''' Remove DC bias before computing RMS.'''
return sum(values) / len(values)
def normalized_rms(values):
''' Normalize values'''
minbuf = int(mean(values))
samples_sum = sum(
float(sample - minbuf) * (sample - minbuf)
for sample in values
)
return math.sqrt(samples_sum / len(values))
samples = array.array('H', [0] * 160)
mic.record(samples, len(samples))
def mix(color_1, color_2, weight_2):
"""
Blend between two colors with a given ratio.
:param color_1: first color, as an (r,g,b) tuple
:param color_2: second color, as an (r,g,b) tuple
:param weight_2: Blend weight (ratio) of second color, 0.0 to 1.0
:return (r,g,b) tuple, blended color
"""
if weight_2 < 0.0:
weight_2 = 0.0
elif weight_2 > 1.0:
weight_2 = 1.0
weight_1 = 1.0 - weight_2
return (int(color_1[0] * weight_1 + color_2[0] * weight_2),
int(color_1[1] * weight_1 + color_2[1] * weight_2),
int(color_1[2] * weight_1 + color_2[2] * weight_2))
def power_on(duration):
"""
Animate NeoPixels for power on.
:param duration: estimated duration of sound, in seconds (>0.0)
"""
prev = 0
start_time = time.monotonic() # Save start time
while True:
elapsed = time.monotonic() - start_time # Time spent
if elapsed > duration: # Past duration?
break # Stop animating
animation_time = elapsed / duration # Animation time, 0.0 to 1.0
threshold = int(NUM_PIXELS * animation_time + 0.5)
num = threshold - prev # Number of pixels to light on this pass
if num != 0:
strip[prev:threshold] = [COLOR] * num
strip.show()
prev = threshold
def fade(duration):
"""
Animate NeoPixels for hit/fade animation
:param duration: estimated duration of sound, in seconds (>0.0)
"""
prev = 0
hit_time = time.monotonic() # Save start time
while True:
elapsed = time.monotonic() - hit_time # Time spent
if elapsed > duration: # Past duration?
break # Stop animating
animation_time = elapsed / duration # Animation time, 0.0 to 1.0
threshold = int(NUM_PIXELS * animation_time + 0.5)
num = threshold - prev # Number of pixels to light on this pass
if num != 0:
blend = time.monotonic() - hit_time # Time since triggered
blend = abs(0.5 - blend) * 2.0 # ramp up, down
strip.fill(mix(COLOR_ACTIVE, COLOR, blend)) # Fade from hit/swing to base color
strip.show()
def light_wave(duration):
"""
Animate NeoPixels for swing animatin
:param duration: estimated duration of sound, in seconds (>0.0)
"""
prev = 0
swing_time = time.monotonic() # Save start time
while True:
elapsed = time.monotonic() - swing_time # Time spent
if elapsed > duration: # Past duration?
break # Stop animating
animation_time = elapsed / duration # Animation time, 0.0 to 1.0
threshold = int(NUM_PIXELS * animation_time + 0.5)
num = threshold - prev # Number of pixels to light on this pass
if num != 0:
strip[prev:threshold] = [CRACK_COLOR] * num
strip.show()
prev = threshold
def whip_crack(duration):
"""
Animate NeoPixels for swing animatin
:param duration: estimated duration of sound, in seconds (>0.0)
"""
prev = 0
crack_time = time.monotonic() # Save start time
while True:
elapsed = time.monotonic() - crack_time # Time spent
if elapsed > duration: # Past duration?
break # Stop animating
animation_time = elapsed / duration # Animation time, 0.0 to 1.0
threshold = int(NUM_PIXELS * animation_time + 0.5)
num = threshold - prev # Number of pixels to light on this pass
if num != 0:
strip.fill(CRACK_COLOR)
strip.show()
time.sleep(0.01)
strip.fill(DARK_COLOR)
strip.show()
time.sleep(0.03)
strip.fill(CRACK_COLOR)
strip.show()
time.sleep(0.02)
strip.fill(DARK_COLOR)
strip.show()
time.sleep(0.005)
strip.fill(CRACK_COLOR)
strip.show()
time.sleep(0.01)
strip.fill(DARK_COLOR)
strip.show()
time.sleep(0.03)
prev = threshold
MODE = 0 # Initial MODE = OFF
# Setup idle pulse
IDLE_BRIGHTNESS = IDLE_PULSE_BRIGHTNESS_MIN # current brightness of idle pulse
IDLE_INCREMENT = 0.01 # Initial idle pulse direction
# Main loop
while True:
if MODE == 0: # If currently off...
enable.value = True
power_on(POWER_ON_DURATION) # Power up!
MODE = 1 # Idle MODE
# Setup for idle pulse
IDLE_BRIGHTNESS = IDLE_PULSE_BRIGHTNESS_MIN
IDLE_INCREMENT = 0.01
strip.fill([int(c*IDLE_BRIGHTNESS) for c in COLOR])
strip.show()
elif MODE >= 1: # If not OFF MODE...
samples = array.array('H', [0] * 160)
mic.record(samples, len(samples))
magnitude = normalized_rms(samples)
print("Sound level:", normalized_rms(samples))
if magnitude > SOUND_THRESHOLD:
whip_crack(WHIP_CRACK_DURATION)
MODE = 4
x, y, z = sensor.acceleration
accel_total = x * x + z * z
# (Y axis isn't needed, due to the orientation that the Prop-Maker
# Wing is mounted. Also, square root isn't needed, since we're
# comparing thresholds...use squared values instead.)
if accel_total > HIT_THRESHOLD: # Large acceleration = HIT
TRIGGER_TIME = time.monotonic() # Save initial time of hit
#play_wav("/sounds/hit1.wav") # Start playing 'hit' sound
COLOR_ACTIVE = COLOR_HIT # Set color to fade from
MODE = 3 # HIT MODE
print("playing HIT")
elif MODE == 1 and accel_total > SWING_THRESHOLD: # Mild = SWING
# make a larson scanner animation_time
strip.fill(DARK_COLOR)
strip_backup = strip[0:-1]
for p in range(-1, len(strip)):
for i in range(p-1, p+10): # shoot a 'ray' of 3 pixels
if 0 <= i < len(strip):
strip[i] = COLOR_SWING
strip.show()
time.sleep(SWING_BLAST_SPEED)
if 0 <= (p-1) < len(strip):
strip[p-1] = strip_backup[p-1] # restore previous color at the tail
strip.show()
MODE = 2 # we'll go back to idle MODE
print("playing SWING")
elif MODE == 1:
# Idle pulse
IDLE_BRIGHTNESS += IDLE_INCREMENT # Pulse up
if IDLE_BRIGHTNESS > IDLE_PULSE_BRIGHTNESS_MAX or \
IDLE_BRIGHTNESS < IDLE_PULSE_BRIGHTNESS_MIN: # Then...
IDLE_INCREMENT *= -1 # Pulse direction flip
strip.fill([int(c*IDLE_BRIGHTNESS) for c in COLOR_IDLE])
strip.show()
time.sleep(IDLE_PULSE_SPEED) # Idle pulse speed set above
elif MODE > 1: # If in SWING or HIT MODE...
if MODE == 3:
fade(FADE_DURATION)
# elif MODE == 2: # If SWING,
# power_on(POWER_ON_DURATION)
MODE = 1 # Return to idle mode
Customizing Your Code
The best way to edit and upload your code is with the Mu Editor, a simple Python editor that works with Adafruit CircuitPython hardware. It's written in Python and works on Windows, MacOS, Linux and Raspberry Pi. The serial console is built right in so you get immediate feedback from your board's serial output. Instructions for installing Mu is here.
Open the code in the Mu editor (or another text editor) and look near the top. You'll see a lot of variables that you can change to customize the color palettes and sensitivity of the motion of your whip.
First, change the value of NUM_PIXELS to match the actual number of pixels in one of your NeoPixel strands. Since they're both wired to the same pin, they'll mirror each other, so we only need to count the pixels in one strand.
NUM_PIXELS = 60 # Number of pixels in your NeoPixel strand
Colors
The default color for the whip at idle is a dark blood orange. The format here is R, G, B -- so we've made orange by mixing 40 Red, 3 Green, and 0 Blue values. You can play with the numbers here to mix your own colors, but be sure to keep the values under around 200. Smaller numbers will make a dimmer light -- I want the idle color to be much dimmer than the animation colors, for extra contrast.
More about mixing colors in CircuitPython can be found here.
# CUSTOMISE COLORS HERE: COLOR = (40, 3, 0) # Default idle is blood orange HIT_COLOR = (0, 250, 0) # hit color is green LIGHT_WAVE_COLOR = (200, 50, 200) # purple DARK_COLOR = (0, 0, 0) CRACK_COLOR = (250, 250, 250) #white
Idle Pulse Animation Speed
Next, you can customize the speed and brightness of the idle pulse animation and the swing blast speed.
# CUSTOMISE IDLE PULSE SPEED HERE: 0 is fast, above 0 slows down IDLE_PULSE_SPEED = 0 # Default is 0 seconds SWING_BLAST_SPEED = 0.007 # CUSTOMISE BRIGHTNESS HERE: must be a number between 0 and 1 IDLE_PULSE_BRIGHTNESS_MIN = 0.1 # Default minimum idle pulse brightness IDLE_PULSE_BRIGHTNESS_MAX = 0.5 # Default maximum idle pulse brightness
Sensitivity
This section allows you to adjust the motion and sound sensitivity of the whip. I have it set up so that the swing animation triggers fairly easily, the hit threshold is a bit harder. The sound threshold is set to 2000, to trigger only when a loud crack is heard.
These numbers will really affect the feel and control of your whip, so don't be afraid to play around with them until it all feels just right.
# CUSTOMISE SENSITIVITY HERE: smaller numbers = more sensitive to motion HIT_THRESHOLD = 1150 SWING_THRESHOLD = 750 SOUND_THRESHOLD = 2000
Animation Timing
Finally, you can change the duration of each animation. If you're a fast whip-cracker, you can set these to fire more quickly. Slow them down if you're more of a whip dancer with fewer cracks.
# Set to the length in seconds for the animations POWER_ON_DURATION = 1.7 LIGHT_WAVE_DURATION = 1 HIT_DURATION = 2 SWING_DURATION = 0 FADE_DURATION = 1 WHIP_CRACK_DURATION = 0.5
Troubleshooting
If it doesn't seem to be working, here are a few things to try:
- Double check you have all the correct libraries installed. Some of the names are really similar -- make sure you've got the right ones.
- Try reinstalling CircuitPython again
- Open the REPL in the Mu editor by clicking the "serial" button. Press <ctrl>D. This will error-check your code and let you know what line number may be the problem. More about the REPL here.
More tips and tricks can be found on the Intro to CircuitPython guide and the Feather Sense guide.
Page last edited January 21, 2025
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