You may need to update the bootloader on your nRF52840 board to install the latest CircuitPython! Use the link below for more info:
Text Editor
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Download the Project Bundle
Your project will use a specific set of CircuitPython libraries, .wav files, and the code.py file. To get everything you need, click on the Download Project Bundle link below, and uncompress the .zip file.
Drag the contents of the uncompressed bundle directory onto your board's CIRCUITPY drive, replacing any existing files or directories with the same names, and adding any new ones that are necessary.
# SPDX-FileCopyrightText: 2022 John Park for Adafruit Industries
# SPDX-License-Identifier: MIT
# BLE Ouija Board
import time
import random
import board
import digitalio
import neopixel
from adafruit_motorkit import MotorKit
from adafruit_ble import BLERadio
from adafruit_ble.advertising.standard import ProvideServicesAdvertisement
from adafruit_ble.services.nordic import UARTService
from adafruit_bluefruit_connect.packet import Packet
from adafruit_bluefruit_connect.button_packet import ButtonPacket
import audiocore
import audiomixer
import audiobusio
# Prep the status LEDs on the Feather
blue_led = digitalio.DigitalInOut(board.BLUE_LED)
red_led = digitalio.DigitalInOut(board.RED_LED)
blue_led.direction = digitalio.Direction.OUTPUT
red_led.direction = digitalio.Direction.OUTPUT
ble = BLERadio()
uart_service = UARTService()
advertisement = ProvideServicesAdvertisement(uart_service)
num_motors = 1 # up to 4 motors depending on the prop you are driving
i2c = board.I2C() # uses board.SCL and board.SDA
# i2c = board.STEMMA_I2C() # For using the built-in STEMMA QT connector on a microcontroller
motorwing = MotorKit(i2c=i2c)
motorwing.frequency = 122 # tune this 50 - 200 range
max_throttle = 0.65 # tune this 0.2 - 1 range
# # make arrays for all the things we care about
motors = [None] * num_motors
motors[0] = motorwing.motor1
# # set motors to "off"
for i in range(num_motors):
motors[i].throttle = None
# - Audio setup
audio = audiobusio.I2SOut(bit_clock=board.TX, word_select=board.MISO, data=board.RX)
mixer = audiomixer.Mixer(voice_count=2, sample_rate=11025, channel_count=1,
bits_per_sample=16, samples_signed=True)
audio.play(mixer) # attach mixer to audio playback
wav_files = (('spooky_ouija.wav', 0.07, True), ('lars_ouija.wav', 0.09, False))
# open samples
for i in range(len(wav_files)):
wave = audiocore.WaveFile(open(wav_files[i][0], "rb"))
mixer.voice[i].level = 0 # start up with level down
mixer.voice[i].play(wave, loop=wav_files[i][2])
# - NeoPixels
fire_color = 0xcc6600
fade_by = -1
num_leds = 7
max_bright = 0.5
led_pin = board.D6
leds = neopixel.NeoPixel(led_pin, num_leds, brightness=0.0, auto_write=False)
leds.fill(fire_color)
leds.show()
last_time = 0
next_duration = 0.2
print("BLE Ouija board")
print("Use Adafruit Bluefruit app to connect")
while True:
blue_led.value = False
ble.name = 'Ouija'
ble.start_advertising(advertisement)
while not ble.connected:
# Wait for a connection.
pass
blue_led.value = True # turn on blue LED when connected
while ble.connected:
if uart_service.in_waiting:
# Packet is arriving.
red_led.value = False # turn off red LED
packet = Packet.from_stream(uart_service)
if isinstance(packet, ButtonPacket) and packet.pressed:
red_led.value = True # blink to show a packet has been received
if packet.button == ButtonPacket.RIGHT: # > button pressed
print("forward")
motors[0].throttle = max_throttle
time.sleep(0.1) # wait a moment
elif packet.button == ButtonPacket.LEFT: # < button
print("reverse")
motors[0].throttle = max_throttle * -1
time.sleep(0.1)
elif packet.button == ButtonPacket.DOWN: # v button
print("stop")
motors[0].throttle = None
time.sleep(0.1)
elif packet.button == ButtonPacket.BUTTON_1: # 1 button
print("on BG music")
mixer.voice[0].level = wav_files[0][1]
time.sleep(0.1)
elif packet.button == ButtonPacket.BUTTON_3: # 3 button
print("off BG music")
mixer.voice[0].level = 0.0
time.sleep(0.1)
elif packet.button == ButtonPacket.BUTTON_2: # 2 button
print("on led & Lars")
leds.brightness = max_bright
mixer.voice[1].play(wave, loop=False)
mixer.voice[1].level = wav_files[1][1]
time.sleep(0.1)
elif packet.button == ButtonPacket.BUTTON_4: # 4 button
print("off led & Lars")
leds.brightness = 0
mixer.voice[1].level = 0.0
time.sleep(0.1)
# fade down all LEDs
leds[:] = [[min(max(i+fade_by, 0), 255) for i in l] for l in leds]
leds.show()
# add new fire to leds
if time.monotonic() - last_time > next_duration:
last_time = time.monotonic()
next_duration = random.uniform(0.95, 1.95) # tune these nums
# for i in range( 1):
c = fire_color # get our color
c = (c >> 16 & 0xff, c >> 8 & 0xff, c & 0xff) # make it a tuple
leds[random.randint(0, num_leds-1)] = c
How It Works
The code imports a number of libraries needed to use the board pins, NeoPixels, BLE, Motor FeatherWing, and audio.
import time import random import board import digitalio import neopixel from adafruit_motorkit import MotorKit from adafruit_ble import BLERadio from adafruit_ble.advertising.standard import ProvideServicesAdvertisement from adafruit_ble.services.nordic import UARTService from adafruit_bluefruit_connect.packet import Packet from adafruit_bluefruit_connect.button_packet import ButtonPacket import audiocore import audiomixer import audiobusio
Setup
Next, the code does the setup for LED indicators, BLE, motor driving, audio, and NeoPixel animation.
blue_led = digitalio.DigitalInOut(board.BLUE_LED)
red_led = digitalio.DigitalInOut(board.RED_LED)
blue_led.direction = digitalio.Direction.OUTPUT
red_led.direction = digitalio.Direction.OUTPUT
ble = BLERadio()
uart_service = UARTService()
advertisement = ProvideServicesAdvertisement(uart_service)
num_motors = 1 # up to 4 motors depending on the prop you are driving
motorwing = MotorKit(i2c=board.I2C())
motorwing.frequency = 122 # tune this 50 - 200 range
max_throttle = 0.65 # tune this 0.2 - 1 range
# # make arrays for all the things we care about
motors = [None] * num_motors
motors[0] = motorwing.motor1
# # set motors to "off"
for i in range(num_motors):
motors[i].throttle = None
# - Audio setup
audio = audiobusio.I2SOut(bit_clock=board.TX, word_select=board.MISO, data=board.RX)
mixer = audiomixer.Mixer(voice_count=2, sample_rate=11025, channel_count=1,
bits_per_sample=16, samples_signed=True)
audio.play(mixer) # attach mixer to audio playback
wav_files = (('spooky_ouija.wav', 0.07, True), ('lars_ouija.wav', 0.09, False))
# open samples
for i in range(len(wav_files)):
wave = audiocore.WaveFile(open(wav_files[i][0], "rb"))
mixer.voice[i].level = 0 # start up with level down
mixer.voice[i].play(wave, loop=wav_files[i][2])
# - NeoPixels
fire_color = 0xcc6600
fade_by = -1
num_leds = 7
max_bright = 0.5
led_pin = board.D6
leds = neopixel.NeoPixel(led_pin, num_leds, brightness=0.0, auto_write=False)
leds.fill(fire_color)
leds.show()
Main Loop
The main loop of the program establishes the BLE advertisement an waits for a connection with the Bluefruit program.
Once connected, the UART service waits to receive packets of button presses. These are translated into motor movement in both directions, motor stop, and enabling or disabling the audio tracks and NeoPixel animations.
while True:
blue_led.value = False
ble.name = 'Ouija'
ble.start_advertising(advertisement)
while not ble.connected:
# Wait for a connection.
pass
blue_led.value = True # turn on blue LED when connected
while ble.connected:
if uart_service.in_waiting:
# Packet is arriving.
red_led.value = False # turn off red LED
packet = Packet.from_stream(uart_service)
if isinstance(packet, ButtonPacket) and packet.pressed:
red_led.value = True # blink to show a packet has been received
if packet.button == ButtonPacket.RIGHT: # > button pressed
print("forward")
motors[0].throttle = max_throttle
time.sleep(0.1) # wait a moment
elif packet.button == ButtonPacket.LEFT: # < button
print("reverse")
motors[0].throttle = max_throttle * -1
time.sleep(0.1)
elif packet.button == ButtonPacket.DOWN: # v button
print("stop")
motors[0].throttle = None
time.sleep(0.1)
elif packet.button == ButtonPacket.BUTTON_1: # 1 button
print("on BG music")
mixer.voice[0].level = wav_files[0][1]
time.sleep(0.1)
elif packet.button == ButtonPacket.BUTTON_3: # 3 button
print("off BG music")
mixer.voice[0].level = 0.0
time.sleep(0.1)
elif packet.button == ButtonPacket.BUTTON_2: # 2 button
print("on led & Lars")
leds.brightness = max_bright
mixer.voice[1].play(wave, loop=False)
mixer.voice[1].level = wav_files[1][1]
time.sleep(0.1)
elif packet.button == ButtonPacket.BUTTON_4: # 4 button
print("off led & Lars")
leds.brightness = 0
mixer.voice[1].level = 0.0
time.sleep(0.1)
Animation
The fade animation on the NeoPixels is run at all times, with the BLE packets only controlling the brightness.
# fade down all LEDs
leds[:] = [[min(max(i+fade_by, 0), 255) for i in l] for l in leds]
leds.show()
# add new fire to leds
if time.monotonic() - last_time > next_duration:
last_time = time.monotonic()
next_duration = random.uniform(0.95, 1.95) # tune these nums
# for i in range( 1):
c = fire_color # get our color
c = (c >> 16 & 0xff, c >> 8 & 0xff, c & 0xff) # make it a tuple
leds[random.randint(0, num_leds-1)] = c
Page last edited January 21, 2025
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