Sunday, 24 November 2024

Adafruit RP2040 Prop-Maker Feather - Staser sound effect

This uses the Prop-Maker Feather'’s I2S audio amplifier to generate a sound effect, in this case a Gallifreyan Staser sound effect.

For testing purposes, the sound is triggered by the use of the Boot button on the board (the Boot button on the Prop-Maker Feather is connected to GPIO7 and named board.Button in CircuitPython)

For use as a prop, the trigger would be wired to the Button terminal and the Ground terminal shared with the NeoPixel.

Getting your sound effect.

The Prop-Maker Feather requires a PCM 16-bit Mono WAV files at a sample rate of 22KHz. This can be created using Audicity by following the Adafruit instructions.

Code

# Staser sound effect

import board

import digitalio

import time

import neopixel

import random

import audiocore

import audiobusio

import audiomixer

import pwmio

import keypad

keys = keypad.Keys((board.BUTTON,), value_when_pressed=False, pull=True)

# One of the features of the prop-maker is that the Neopixel

# (and the amplifier and the speaker) can be switched on and off

external_power = digitalio.DigitalInOut(board.EXTERNAL_POWER)

external_power.direction = digitalio.Direction.OUTPUT

external_power.value = True

audio = audiobusio.I2SOut(board.I2S_BIT_CLOCK, board.I2S_WORD_SELECT, board.I2S_DATA)

def play(filename, audio):

# i2s playback

wave_file = open(filename, "rb")

wave = audiocore.WaveFile(wave_file)

mixer = audiomixer.Mixer(voice_count=1, sample_rate=22050, channel_count=1,

bits_per_sample=16, samples_signed=True)

audio.play(mixer)

mixer.voice[0].play(wave, loop=False)

mixer.voice[0].level = 0.5

print("Fire")

wave_file

while True:

event = keys.events.get()

# event will be None if nothing has happened.

if event:

if event.pressed:

play("staser.wav",audio)

print("Done")

References

https://learn.adafruit.com/adafruit-rp2040-prop-maker-feather/overview

https://learn.adafruit.com/key-pad-matrix-scanning-in-circuitpython/keys-one-key-per-pin

https://learn.adafruit.com/microcontroller-compatible-audio-file-conversion

https://learn.adafruit.com/lightsaber-rp2040/code-the-lightsaber

Adafruit RP2040 Prop-Maker Feather

The Adafruit RP2040 Prop-Maker Feather is an Adafruit Feather format board using the Raspberry Pi RP2040 processor with 8MB of QSPI FLASH with a terminal block connector at one end, QWIC/STEMMA connector, Servo connector and adjacent to the USB type C connector a battery connector (with charging capability). It can be used without any soldering.

There is a slightly more in-depth discussion here.

The terminal block has three connections for the NeoPixels (5V, ground and data), two for a 4-8 ohm speaker and one for a button.

Assembly

This set up is going to use a 500mm strip of 332 LED per metre ultra dense strip.

It is supplied with a female connector and a matching male connector with wires to connect to the Feather’s terminals.

Unfortunately, due to not completely comprehending the operation of the NeoPixel driver, I went through a number of iterations on connection, including removing the connector on the strip before finally realising that the NeoPixel driver is by default OFF, and a pin needs to be set to make it (and the speaker driver) live. Once that was set and the wires appropriately connected everything was fine.

Installation

CircuitPython is derived from MicroPython and makes the device appear as a USB storage device on the host computer.

This means that any editor can be used to edit the CircuitPython source as long as when it saves, it saves everything to the device.

I use a slightly different method, I have a simple Visual Studio program that I use to copy all the required files to the device - and develop using Visual Studio Code. This means that there is always a copy of the code on the laptop in the event that the device becomes unreadable.

The alternative is to use an IDE like MU.

Download the latest version of CircuitPython for the board from the CircuitPython site.

Connect the Prop-Maker Feather to the computer with a known good data (not charge only cable).

The Prop-Maker Feather has a Reset and a Boot Select button. This makes entering the Bootloader a lot easier tan having to unplu and plug the device in while holding down a tiny button.

Hold down the BOOT button and while continuing to hold it, press and release the reset button. Keep holding the BOOT button until a RPI-RP2 drive on the computer.

Copy and paste the UF2 file into the drive. When it has finished copying, the Feather will reboot.

Coding

This program repeatedly through runs the NeoPixel strip through a number of colours. The onboard LED is flashed during each cycle.

# Imports

import board

import digitalio

import time

import neopixel

# Use the builtin LED as a pulse

led = digitalio.DigitalInOut(board.LED)

led.direction = digitalio.Direction.OUTPUT

# Set a list of colour combinations

COLORS = (

(255, 0, 0),

( 0, 255, 0),

( 0, 0, 255),

(255, 255, 0),

(255, 0, 255),

( 0, 255, 255),

)

# Set up Neopixels

# This is for a 0.5m Ultra-dense RGB Micro LED Strip with 332 LEDs per metre

num_pixels = 165

pixels = neopixel.NeoPixel(board.EXTERNAL_NEOPIXELS, num_pixels, auto_write=True)

pixels.brightness = 0.02

# One of the features of the prop-maker is that the Neopixel

# (and the amplifier and the speaker) can be switched on and off

external_power = digitalio.DigitalInOut(board.EXTERNAL_POWER)

external_power.direction = digitalio.Direction.OUTPUT

external_power.value = True

# Loop indefinitely

while True:

# Loop through the colour list

for color in COLORS:

# Set the built in LED on

led.value = True

time.sleep(0.5)

# Set each pixel in turn

for i in range(num_pixels):

pixels[i] = color

pixels.show()

# Set the built in LED off

led.value = False

time.sleep(0.5)

Here is the device in action.

References

https://shop.pimoroni.com/products/adafruit-rp2040-prop-maker-feather-with-i2s-audio-amplifier?variant=41128910454867

https://shop.pimoroni.com/products/neon-like-rgb-micro-led-strip?variant=39395564585043

https://circuitpython.org/board/adafruit_feather_rp2040_prop_maker/

https://circuitpython.org/libraries

https://learn.adafruit.com/adafruit-rp2040-prop-maker-feather/overview

https://learn.adafruit.com/lightsaber-rp2040/code-the-lightsaber