CIRCUITPYcode.py with the example script.
Thankfully, we can do this in one go. In the example below, click the Download Project Bundle button below to download the necessary libraries and the code.py file in a zip file. Extract the contents of the zip file, open the directory MP3_Tap_Player/ and then click on the directory that matches the version of CircuitPython you're using and copy the contents of that directory to your CIRCUITPY drive.
CIRCUITPY
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.
# SPDX-FileCopyrightText: 2020 John Park for Adafruit Industries
#
# SPDX-License-Identifier: MIT
# MP3 playback with tap trigger
# Works on Feather M4 (or other M4 based boards) with Propmaker
import time
import board
import busio
import digitalio
import audioio
import audiomp3
import adafruit_lis3dh
startup_play = False # set to True to play all samples once on startup
# Set up accelerometer on I2C bus
i2c = busio.I2C(board.SCL, board.SDA)
int1 = digitalio.DigitalInOut(board.D6)
accel = adafruit_lis3dh.LIS3DH_I2C(i2c, int1=int1)
accel.set_tap(1, 100) # single or double-tap, threshold
# Set up speaker enable pin
enable = digitalio.DigitalInOut(board.D10)
enable.direction = digitalio.Direction.OUTPUT
enable.value = True
speaker = audioio.AudioOut(board.A0)
sample_number = 0
print("Lars says, 'Hello, CVT Joseph. Tap to play.'")
if startup_play: # Play all on startup
for i in range(10):
sample = "/lars/lars_0{}.mp3".format(i)
print("Now playing: '{}'".format(sample))
mp3stream = audiomp3.MP3Decoder(open(sample, "rb"))
speaker.play(mp3stream)
while speaker.playing:
time.sleep(0.1)
enable.value = speaker.playing
while True:
if accel.tapped and speaker.playing is False:
sample = "/lars/lars_0{}.mp3".format(sample_number)
print("Now playing: '{}'".format(sample))
mp3stream = audiomp3.MP3Decoder(open(sample, "rb"))
speaker.play(mp3stream)
sample_number = (sample_number + 1) % 10
enable.value = speaker.playing
Audio Samples
You can get started by using these .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 /lars 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
How It Works
Here's what the code does:
- Imports the necessary libraries for audiomp3 playback and accelerometer tap detection with the adafruit_lis3dh
- Sets up the accelerometer
- Specifies the speaker enable pin (this allows the speaker to be disabled when not in use)
- If startup_play is set to True, each sample in the
/larsdirectory with the name format of/lars_0*.mp3will be played using themp3streamobject - In the main loop of the program, the accelerometer is checked for tap detection. When the tap occurs, the next sample is played. When the tenth one is played, the list loops around back to the first one again.
Test It
With the enable switch clicked on, try tapping the Feather/Propmaker to trigger a sample. When a sample has finished you can tap again to trigger the next one.
Note, there is a small volume adjustment screw on the Propmaker FeatherWing that can be turned with a small screwdriver to adjust the maximum volume.
Now, let's add the sound player to our puppet friend Lars!
