Audio playback peripheral interface with MAX98357 (I²S) backend
Repository: github.com/dekiengine/deki-audio · Latest release: 0.19.0 · Needs engine 0.19.0+ · Requires: deki-i2s
Install with DekiEditor --packages-add deki-audio <project>, or from the Package Manager. The engine's own components and C++ API are in the Deki docs.
Shown in the editor as Audio (Speaker / PCM playback).
Components
| Component | Category | Description |
|---|---|---|
| MAX98357AudioComponent | Sensors | Plays sound through a MAX98357A I2S amplifier. |
Feature flags
Parts you can leave out of a build. A feature with a define is switched there; the rest are stripped with their components.
| Feature | Define | Default |
|---|---|---|
| MAX98357A (I²S class-D mono amp, 16-bit PCM) | DEKI_FEATURE_AUDIO_MAX98357 | on |
Component reference
MAX98357AudioComponent
Plays sound through a MAX98357A I2S amplifier.
Inspector name: MAX98357A Audio · Category: Sensors · Type: DekiAudio::MAX98357AudioComponent
| Property | Type | Default | Constraints | Description |
|---|---|---|---|---|
| i2sPort | int32 | 0 | 0 to 1 | Which of the chip's I2S controllers drives the amplifier. Most boards only use one. |
| bclkPin | int32 | 39 | 0 to 48 | GPIO carrying the bit clock (BCLK), which ticks once per audio bit. |
| lrclkPin | int32 | 40 | 0 to 48 | GPIO carrying the word select line (LRCLK or WS), which marks left and right samples. Some boards label it LRC. |
| dinPin | int32 | 5 | 0 to 48 | GPIO carrying the audio data into the amplifier (DIN). This is the one sound actually travels on. |
| sampleRate | int32 | 16000 | 8000 to 48000 | Samples per second. 16 kHz is plenty for speech and effects and cheap on memory; 44100 is CD rate and costs nearly three times the bandwidth. |
| channels | int32 | 1 | 1 to 2 | 1 for mono, 2 for stereo. The MAX98357 is a mono amplifier, so stereo material is mixed down unless a second one is wired for the other channel. |
| initialVolume | int32 | 80 | 0 to 100 | Volume at startup, 0 to 100. Applies before the first sound plays, so a project can come up quiet rather than at full output. |
Changelog
0.19.0
Changed
- minEngine 0.19.0: built against engine 0.19.0, whose component metadata records the package each class is in. A build of this package from before does not load and is rebuilt.
Added
- Japanese, Simplified Chinese and Korean: editor/lang/ja.json, zh.json and ko.json translate the names, tooltips and enum values this package's components show in the Inspector.
- The package's editor text goes through the editor's translation (Tr), so it shows in the editor's language. Needs the editor release that adds Localization.h; raise minEngine to it when releasing.
0.18.0
Changed
- minEngine 0.18.0. Reflection ABI 21: the package must be rebuilt.
- Names follow the code style (deki-engine/docs/codestyle): types, functions and enum values are PascalCase, constants kPascalCase, members m_PascalCase, locals and parameters camelCase. The code is formatted with clang-format 22.
- The functions the editor finds by name are PascalCase: DekiAudioRegisterComponents, DekiAudioGetAutoComponentCount, DekiAudioEnsureRegistered and the rest. Built against engine ABI 21; a build of this package from before does not load and is rebuilt.
Fixed
- MAX98357A: after Stop() the speaker stayed silent until a restart, because playing never turned the I2S channel back on. PlayPCM now does.
- MAX98357A: PlayPCM copied the whole clip into internal RAM to apply the volume, so a long clip ran the board out of memory. It now scales a small chunk at a time.
- MAX98357A: initializing twice leaked the first I2S channel, and a channel that failed to start was left open.
Removed
- The former names from before 0.16.0 (bare class names, and deki-gpio's DekiEsp32::ESP32PinSetup). A scene that old is upgraded with 0.17 first.
Earlier releases: CHANGELOG.md.
Generated from the package's reflection data (engine 0.19.0). Property names are the keys used in scene files. Renames keep an alias (compatibility).
