Matt Spencer
496b6bdc71
Key components: - no_std core so it can be used bare metal on embedded systems - default implementation for RPi 2350, with midi input and I2s output using PIO - Visualiser for the web to play with on a dev system
100 lines
3.1 KiB
Markdown
100 lines
3.1 KiB
Markdown
# Sound — Analogue Synthesiser
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A modular analogue synthesiser written in Rust.
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- **`synth-core`** — `no_std` DSP library (oscillators, filters, envelopes, LFO, MIDI). Runs on microcontrollers and WASM.
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- **`synth-visualiser`** — browser-based visualiser (oscilloscope, spectrum analyser, patch bay) compiled to WebAssembly.
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## Prerequisites
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```sh
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# Rust toolchain (stable)
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curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
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# WASM target
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rustup target add wasm32-unknown-unknown
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# wasm-pack (builds and packages the WASM module)
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cargo install wasm-pack
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```
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## Build
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### synth-core (native — tests and development)
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```sh
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cargo build -p synth-core
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cargo test -p synth-core
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```
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### synth-core (WASM — verify it cross-compiles)
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```sh
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cargo build -p synth-core --target wasm32-unknown-unknown
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```
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### synth-visualiser (browser)
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Run from the workspace root:
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```sh
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wasm-pack build crates/synth-visualiser --target web --out-dir ../../www/pkg
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```
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This generates `www/pkg/` containing the compiled `.wasm` binary and the JS glue module.
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## Run
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Serve the `www/` directory with any static HTTP server. A browser is required (the Web Audio API is not available over `file://`).
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```sh
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# Python (no install needed)
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python3 -m http.server --directory www 8080
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# Or with npx serve
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npx serve www
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```
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Then open [http://localhost:8080](http://localhost:8080).
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## Microcontroller deployment
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`synth-core` targets bare-metal Cortex-M out of the box. Add the relevant target and uncomment the linker flags in [`.cargo/config.toml`](.cargo/config.toml).
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```sh
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# Example: Daisy Seed / STM32H750 (Cortex-M7)
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rustup target add thumbv7em-none-eabihf
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cargo build -p synth-core --target thumbv7em-none-eabihf
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```
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A microcontroller runner crate (I²S output, UART MIDI) can be added as a new workspace member when needed.
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## Project structure
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```
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sound/
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├── crates/
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│ ├── synth-core/ # no_std DSP library
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│ │ └── src/
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│ │ ├── oscillator.rs VCO — Sine, Saw, Square, Triangle, Pulse
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│ │ ├── filter.rs SVF — LP / HP / BP / Notch
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│ │ ├── envelope.rs ADSR envelope generator
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│ │ ├── vca.rs Voltage-controlled amplifier
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│ │ ├── lfo.rs Low-frequency oscillator
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│ │ ├── midi.rs Byte-stream MIDI parser
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│ │ ├── patch.rs Cable routing graph
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│ │ ├── math.rs DSP utilities (lerp, dB, MIDI→Hz)
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│ │ └── config.rs SampleRate type
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│ └── synth-visualiser/ # WASM browser front-end
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│ └── src/
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│ ├── engine.rs AudioContext + AnalyserNode
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│ ├── oscilloscope.rs Time-domain canvas view
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│ ├── spectrum.rs FFT canvas view
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│ ├── patchbay.rs Drag-and-drop patch cables
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│ └── params.rs SynthParams (JSON serialisable)
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└── www/
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├── index.html Browser UI
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├── bootstrap.js WASM loader (ES module)
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└── pkg/ Generated by wasm-pack (git-ignored)
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```
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