audiobusio – Support for audio input and output over digital buses

The audiobusio module contains classes to provide access to audio IO over digital buses. These protocols are used to communicate audio to other chips in the same circuit. It doesn’t include audio interconnect protocols such as S/PDIF.

All classes change hardware state and should be deinitialized when they are no longer needed. To do so, either call deinit() or use a context manager.

Available on these boards
  • 0xCB Helios
  • 42. Keebs Frood
  • ARAMCON Badge 2019
  • ARAMCON2 Badge
  • ATMegaZero ESP32-S2
  • Adafruit BLM Badge
  • Adafruit CLUE nRF52840 Express
  • Adafruit Circuit Playground Bluefruit
  • Adafruit Circuit Playground Express 4-H
  • Adafruit CircuitPlayground Express
  • Adafruit CircuitPlayground Express with Crickit libraries
  • Adafruit CircuitPlayground Express with displayio
  • Adafruit EdgeBadge
  • Adafruit Feather Bluefruit Sense
  • Adafruit Feather ESP32 V2
  • Adafruit Feather ESP32-S2 Reverse TFT
  • Adafruit Feather ESP32-S2 TFT
  • Adafruit Feather ESP32-S3 Reverse TFT
  • Adafruit Feather ESP32-S3 TFT
  • Adafruit Feather ESP32S2
  • Adafruit Feather ESP32S3 4MB Flash 2MB PSRAM
  • Adafruit Feather ESP32S3 No PSRAM
  • Adafruit Feather HUZZAH32
  • Adafruit Feather M0 Express
  • Adafruit Feather M0 Express with Crickit libraries
  • Adafruit Feather M4 CAN
  • Adafruit Feather M4 Express
  • Adafruit Feather MIMXRT1011
  • Adafruit Feather RP2040
  • Adafruit Feather RP2040 CAN
  • Adafruit Feather RP2040 DVI
  • Adafruit Feather RP2040 Prop-Maker
  • Adafruit Feather RP2040 RFM
  • Adafruit Feather RP2040 Scorpio
  • Adafruit Feather RP2040 ThinkInk
  • Adafruit Feather RP2040 USB Host
  • Adafruit Feather nRF52840 Express
  • Adafruit Floppsy RP2040
  • Adafruit FunHouse
  • Adafruit Grand Central M4 Express
  • Adafruit HUZZAH32 Breakout
  • Adafruit Hallowing M4 Express
  • Adafruit ItsyBitsy ESP32
  • Adafruit ItsyBitsy M0 Express
  • Adafruit ItsyBitsy RP2040
  • Adafruit ItsyBitsy nRF52840 Express
  • Adafruit KB2040
  • Adafruit LED Glasses Driver nRF52840
  • Adafruit Macropad RP2040
  • Adafruit MagTag
  • Adafruit Matrix Portal M4
  • Adafruit MatrixPortal S3
  • Adafruit Metro ESP32S2
  • Adafruit Metro ESP32S3
  • Adafruit Metro M0 Express
  • Adafruit Metro M4 Airlift Lite
  • Adafruit Metro M4 Express
  • Adafruit Metro RP2040
  • Adafruit Metro nRF52840 Express
  • Adafruit PyGamer
  • Adafruit PyPortal
  • Adafruit PyPortal Pynt
  • Adafruit PyPortal Titano
  • Adafruit Pybadge
  • Adafruit QT Py ESP32 PICO
  • Adafruit QT Py ESP32-S3 4MB Flash 2MB PSRAM
  • Adafruit QT Py ESP32-S3 no psram
  • Adafruit QT Py ESP32S2
  • Adafruit QT Py M0 Haxpress
  • Adafruit QT Py RP2040
  • Adafruit QT2040 Trinkey
  • Adafruit-Qualia-S3-RGB666
  • AloriumTech Evo M51
  • Arduino Nano 33 BLE
  • Arduino Nano ESP32
  • Arduino Nano RP2040 Connect
  • Artisense Reference Design RD00
  • AtelierDuMaker nRF52840 Breakout
  • BBQ20KBD
  • BDMICRO VINA-D21
  • BDMICRO VINA-D51
  • BLE-SS dev board Multi Sensor
  • BLING!
  • BLOK
  • BPI-Bit-S2
  • BPI-Leaf-S3
  • BPI-PicoW-S3
  • BastBLE
  • BastWiFi
  • Bee-Data-Logger
  • Bee-Motion-S3
  • Bee-S3
  • BlizzardS3
  • BlueMicro840
  • COSMO-Pico
  • CP32-M4
  • CRCibernetica IdeaBoard
  • Cedar Grove StringCar M0 Express
  • Challenger NB RP2040 WiFi
  • Challenger RP2040 LTE
  • Challenger RP2040 LoRa
  • Challenger RP2040 SD/RTC
  • Challenger RP2040 SubGHz
  • Challenger RP2040 WiFi
  • Challenger RP2040 WiFi/BLE
  • Circuit Playground Express Digi-Key PyCon 2019
  • CircuitBrains Basic
  • CircuitBrains Deluxe
  • ColumbiaDSL-Sensor-Board-V1
  • CrumpS2
  • Cytron EDU PICO W
  • Cytron Maker Feather AIoT S3
  • Cytron Maker Nano RP2040
  • Cytron Maker Pi RP2040
  • Cytron Maker Uno RP2040
  • DFRobot FireBeetle 2 ESP32-S3
  • Datanoise PicoADK
  • Deneyap Kart
  • Deneyap Kart 1A
  • Deneyap Kart 1A v2
  • Deneyap Mini
  • Deneyap Mini v2
  • DynOSSAT-EDU-EPS
  • DynOSSAT-EDU-OBC
  • E-Fidget
  • ELECFREAKS PICO:ED
  • ES3ink
  • ESP 12k NodeMCU
  • ESP32 Devkit V1
  • ESP32-S2-DevKitC-1-N4
  • ESP32-S2-DevKitC-1-N4R2
  • ESP32-S2-DevKitC-1-N8R2
  • ESP32-S3-Box-2.5
  • ESP32-S3-Box-Lite
  • ESP32-S3-DevKitC-1-N32R8
  • ESP32-S3-DevKitC-1-N8
  • ESP32-S3-DevKitC-1-N8R2
  • ESP32-S3-DevKitC-1-N8R8
  • ESP32-S3-DevKitC-1-N8R8-with-HACKTABLET
  • ESP32-S3-DevKitM-1-N8
  • ESP32-S3-EYE
  • ESP32-S3-USB-OTG-N8
  • Electrolama minik
  • Electronic Cats Hunter Cat NFC
  • Electronut Labs Blip
  • Electronut Labs Papyr
  • EncoderPad RP2040
  • Espressif ESP32 DevKitc V4 WROOM-32E
  • Espressif ESP32 DevKitc V4 WROVER
  • Espressif ESP32-EYE
  • Espressif ESP32-LyraT
  • Espressif-ESP32-S3-LCD-EV-Board
  • Feather MIMXRT1011
  • Feather MIMXRT1062
  • FeatherS2
  • FeatherS2 Neo
  • FeatherS2 PreRelease
  • FeatherS3
  • Fig Pi
  • Flipper Zero Wi-Fi Dev
  • Franzininho WIFI w/Wroom
  • Franzininho WIFI w/Wrover
  • Gravitech Cucumber M
  • Gravitech Cucumber MS
  • Gravitech Cucumber R
  • Gravitech Cucumber RS
  • HEIA-FR Picomo V2
  • HMI-DevKit-1.1
  • Hack Club Sprig
  • Hacked Feather M0 Express with 8Mbyte SPI flash
  • Hardkernel Odroid Go
  • Heltec ESP32-S3-WIFI-LoRa-V3
  • HexKyS2
  • HiiBot BlueFi
  • IMXRT1010-EVK
  • IMXRT1015-EVK
  • IkigaiSense Vita nRF52840
  • IoTs2
  • Kaluga 1
  • LILYGO T-DECK
  • LILYGO T-DISPLAY
  • LILYGO T-DISPLAY S3 v1.2
  • LILYGO TEMBED ESP32S3
  • LILYGO TTGO T-DISPLAY v1.1
  • LILYGO TTGO T-DISPLAY v1.1 4M
  • LILYGO TTGO T8 ESP32-S2
  • LILYGO TTGO T8 ESP32-S2 w/Display
  • LOLIN S3 16MB Flash 8MB PSRAM
  • LOLIN S3 MINI 4MB Flash 2MB PSRAM
  • Lilygo T-watch 2020 V3
  • M5Stack Atom Echo
  • M5Stack Atom Lite
  • M5Stack Atom Matrix
  • M5Stack Atom U
  • M5Stack AtomS3
  • M5Stack AtomS3 Lite
  • M5Stack AtomS3U
  • M5Stack Core Basic
  • M5Stack Core Fire
  • M5Stack Core2
  • M5Stack Dial
  • M5Stack M5Paper
  • M5Stack Stick C
  • M5Stack Stick C Plus
  • M5Stack Timer Camera X
  • MDBT50Q-DB-40
  • MDBT50Q-RX Dongle
  • MORPHEANS MorphESP-240
  • MagiClick S3 N4R2
  • Maker badge by Czech maker
  • MakerDiary nRF52840 MDK
  • MakerDiary nRF52840 MDK USB Dongle
  • MakerFabs-ESP32-S3-Parallel-TFT-With-Touch-7inch
  • Makerdiary M60 Keyboard
  • Makerdiary Pitaya Go
  • Makerdiary nRF52840 Connect Kit
  • Makerdiary nRF52840 M.2 Developer Kit
  • Maple Computing Elite-Pi
  • Melopero Shake RP2040
  • Metro MIMXRT1011
  • MicroDev microS2
  • MixGo CE
  • NanoS3
  • Neuron
  • Oak Dev Tech BREAD2040
  • Oak Dev Tech Cast-Away RP2040
  • Oak Dev Tech PixelWing ESP32S2
  • Open Hardware Summit 2020 Badge
  • Oxocard Artwork
  • Oxocard Connect
  • Oxocard Galaxy
  • Oxocard Science
  • P1AM-200
  • PCA10056 nRF52840-DK
  • PCA10059 nRF52840 Dongle
  • PCA10100 nRF52833 DK
  • Pajenicko PicoPad
  • Particle Argon
  • Particle Boron
  • Particle Xenon
  • PillBug
  • Pimoroni Badger 2040
  • Pimoroni Badger 2040 W
  • Pimoroni Inky Frame 5.7
  • Pimoroni Inky Frame 7.3
  • Pimoroni Interstate 75
  • Pimoroni Keybow 2040
  • Pimoroni Motor 2040
  • Pimoroni PGA2040
  • Pimoroni Pico DV Base W
  • Pimoroni Pico LiPo (16MB)
  • Pimoroni Pico LiPo (4MB)
  • Pimoroni Pico dv Base
  • Pimoroni PicoSystem
  • Pimoroni Plasma 2040
  • Pimoroni Plasma 2040W
  • Pimoroni Servo 2040
  • Pimoroni Tiny 2040 (2MB)
  • Pimoroni Tiny 2040 (8MB)
  • ProS3
  • PyKey 18 Numpad
  • PyKey 44 Ergo
  • PyKey 60
  • PyKey 87 TKL
  • RP2.65-F
  • RP2040 Stamp
  • Raspberry Breadstick
  • Raspberry Pi Pico
  • Raspberry Pi Pico W
  • S2Mini
  • S2Pico
  • SAM E54 Xplained Pro
  • SAM32v26
  • SSCI ISP1807 Dev Board
  • SSCI ISP1807 Micro Board
  • Saola 1 w/Wroom
  • Saola 1 w/Wrover
  • Seeed XIAO nRF52840 Sense
  • Seeeduino Wio Terminal
  • Seeeduino XIAO RP2040
  • Serpente
  • Silicognition LLC M4-Shim
  • Silicognition LLC RP2040-Shim
  • Simmel
  • SparkFun MicroMod RP2040 Processor
  • SparkFun MicroMod SAMD51 Processor
  • SparkFun MicroMod nRF52840 Processor
  • SparkFun Pro Micro RP2040
  • SparkFun Pro nRF52840 Mini
  • SparkFun RedBoard Turbo
  • SparkFun Teensy MicroMod Processor
  • SparkFun Thing Plus - RP2040
  • SparkFun Thing Plus - SAMD51
  • StackRduino M0 PRO
  • SuperMini NRF52840
  • Swan R5
  • TG-Boards' Datalore IP M4
  • TG-Watch
  • TTGO T8 ESP32-S2-WROOM
  • Targett Module Clip w/Wroom
  • Targett Module Clip w/Wrover
  • Teensy 4.0
  • Teensy 4.1
  • Teknikio Bluebird
  • The Open Book Feather
  • TinkeringTech ScoutMakes Azul
  • TinyPICO
  • TinyPICO Nano
  • TinyS2
  • TinyS3
  • TinyWATCH S3
  • Trinket M0 Haxpress
  • UARTLogger II
  • VCC-GND Studio YD RP2040
  • VCC-GND YD-ESP32-S3 (N16R8)
  • VCC-GND YD-ESP32-S3 (N8R8)
  • W5100S-EVB-Pico
  • W5500-EVB-Pico
  • WSC-1450
  • WarmBit BluePixel nRF52840
  • Waveshare ESP32-S2-Pico
  • Waveshare ESP32-S2-Pico-LCD
  • Waveshare ESP32-S3-Pico
  • Waveshare ESP32-S3-Zero
  • Waveshare RP2040-LCD-0.96
  • Waveshare RP2040-LCD-1.28
  • Waveshare RP2040-Plus (16MB)
  • Waveshare RP2040-Plus (4MB)
  • Waveshare RP2040-TOUCH-LCD-1.28
  • Waveshare RP2040-Zero
  • WeAct Studio Pico
  • WeAct Studio Pico 16MB
  • WisdPi Ardu2040M
  • WisdPi Tiny RP2040
  • iLabs Challenger 840
  • iMX RT 1020 EVK
  • iMX RT 1040 EVK
  • iMX RT 1050 EVKB
  • iMX RT 1060 EVK
  • iMX RT 1060 EVKB
  • keithp.com snekboard
  • micro:bit v2
  • nanoESP32-S2 w/Wrover
  • nanoESP32-S2 w/Wroom
  • nice!nano
  • nullbits Bit-C PRO
  • senseBox MCU-S2 ESP32S2
  • splitkb.com Liatris
  • takayoshiotake Octave RP2040
  • uGame22

class audiobusio.I2SOut(bit_clock: microcontroller.Pin, word_select: microcontroller.Pin, data: microcontroller.Pin, *, main_clock: microcontroller.Pin | None = None, left_justified: bool = False)

Output an I2S audio signal

Create a I2SOut object associated with the given pins.

Parameters:
  • bit_clock (Pin) – The bit clock (or serial clock) pin

  • word_select (Pin) – The word select (or left/right clock) pin

  • data (Pin) – The data pin

  • main_clock (Pin) – The main clock pin

  • left_justified (bool) – True when data bits are aligned with the word select clock. False when they are shifted by one to match classic I2S protocol.

Simple 8ksps 440 Hz sine wave on Metro M0 Express using UDA1334 Breakout:

import audiobusio
import audiocore
import board
import array
import time
import math

# Generate one period of sine wave.
length = 8000 // 440
sine_wave = array.array("H", [0] * length)
for i in range(length):
    sine_wave[i] = int(math.sin(math.pi * 2 * i / length) * (2 ** 15) + 2 ** 15)

sine_wave = audiocore.RawSample(sine_wave, sample_rate=8000)
i2s = audiobusio.I2SOut(board.D1, board.D0, board.D9)
i2s.play(sine_wave, loop=True)
time.sleep(1)
i2s.stop()

Playing a wave file from flash:

import board
import audiocore
import audiobusio
import digitalio


f = open("cplay-5.1-16bit-16khz.wav", "rb")
wav = audiocore.WaveFile(f)

a = audiobusio.I2SOut(board.D1, board.D0, board.D9)

print("playing")
a.play(wav)
while a.playing:
  pass
print("stopped")
playing: bool

True when the audio sample is being output. (read-only)

paused: bool

True when playback is paused. (read-only)

deinit() None

Deinitialises the I2SOut and releases any hardware resources for reuse.

__enter__() I2SOut

No-op used by Context Managers.

__exit__() None

Automatically deinitializes the hardware when exiting a context. See Lifetime and ContextManagers for more info.

play(sample: circuitpython_typing.AudioSample, *, loop: bool = False) None

Plays the sample once when loop=False and continuously when loop=True. Does not block. Use playing to block.

Sample must be an audiocore.WaveFile, audiocore.RawSample, audiomixer.Mixer or audiomp3.MP3Decoder.

The sample itself should consist of 8 bit or 16 bit samples.

stop() None

Stops playback.

pause() None

Stops playback temporarily while remembering the position. Use resume to resume playback.

resume() None

Resumes sample playback after pause().

class audiobusio.PDMIn(clock_pin: microcontroller.Pin, data_pin: microcontroller.Pin, *, sample_rate: int = 16000, bit_depth: int = 8, mono: bool = True, oversample: int = 64, startup_delay: float = 0.11)

Record an input PDM audio stream

Create a PDMIn object associated with the given pins. This allows you to record audio signals from the given pins. Individual ports may put further restrictions on the recording parameters. The overall sample rate is determined by sample_rate x oversample, and the total must be 1MHz or higher, so sample_rate must be a minimum of 16000.

Parameters:
  • clock_pin (Pin) – The pin to output the clock to

  • data_pin (Pin) – The pin to read the data from

  • sample_rate (int) – Target sample_rate of the resulting samples. Check sample_rate for actual value. Minimum sample_rate is about 16000 Hz.

  • bit_depth (int) – Final number of bits per sample. Must be divisible by 8

  • mono (bool) – True when capturing a single channel of audio, captures two channels otherwise

  • oversample (int) – Number of single bit samples to decimate into a final sample. Must be divisible by 8

  • startup_delay (float) – seconds to wait after starting microphone clock to allow microphone to turn on. Most require only 0.01s; some require 0.1s. Longer is safer. Must be in range 0.0-1.0 seconds.

Limitations: On SAMD and RP2040, supports only 8 or 16 bit mono input, with 64x oversampling. On nRF52840, supports only 16 bit mono input at 16 kHz; oversampling is fixed at 64x. Not provided on nRF52833 for space reasons. Not available on Espressif.

For example, to record 8-bit unsigned samples to a buffer:

import audiobusio
import board

# Prep a buffer to record into
b = bytearray(200)
with audiobusio.PDMIn(board.MICROPHONE_CLOCK, board.MICROPHONE_DATA, sample_rate=16000) as mic:
    mic.record(b, len(b))

To record 16-bit unsigned samples to a buffer:

import audiobusio
import board

# Prep a buffer to record into.
b = array.array("H", [0] * 200)
with audiobusio.PDMIn(board.MICROPHONE_CLOCK, board.MICROPHONE_DATA, sample_rate=16000, bit_depth=16) as mic:
    mic.record(b, len(b))
sample_rate: int

The actual sample_rate of the recording. This may not match the constructed sample rate due to internal clock limitations.

deinit() None

Deinitialises the PDMIn and releases any hardware resources for reuse.

__enter__() PDMIn

No-op used by Context Managers.

__exit__() None

Automatically deinitializes the hardware when exiting a context.

record(destination: circuitpython_typing.WriteableBuffer, destination_length: int) None

Records destination_length bytes of samples to destination. This is blocking.

An IOError may be raised when the destination is too slow to record the audio at the given rate. For internal flash, writing all 1s to the file before recording is recommended to speed up writes.

Returns:

The number of samples recorded. If this is less than destination_length, some samples were missed due to processing time.