libpo32
A small C99 library for Teenage Engineering PO-32 acoustic data transfers
and drum synthesis.
libpo32 reimplements the PO-32 Tonic transfer stack and a compatible drum
voice model. It is not a full PO-32 firmware or UI emulator; it covers the
packet format, acoustic modem, frame decoder, and local drum synthesis needed
to build, send, receive, and preview PO-32 transfers.
Contents
Overview
| Area | What libpo32 provides |
|---|
| Transfer protocol | Build and parse PO-32 patch, pattern, and state packets |
| Acoustic modem | Render transfer frames to DPSK audio for playback into the device |
The core is freestanding C99: no libc runtime, no external DSP libraries,
no platform audio APIs, no file I/O. Only the freestanding headers
<stddef.h> and <stdint.h> are used. Suitable for embedded targets and
bare-metal environments.
Using It With a PO-32
The PO-32 is not receiving finished drum audio when you transfer a sound or a
pattern. It receives structured data:
| Data | Meaning |
|---|
| Patch packets | The two patch endpoints per instrument (Left and Right), with the destination instrument slot encoded in the packet |
|
The device then uses its own internal synth engine to turn those parameters
into sound.
At a high level, the workflow with real hardware is:
| Step | What you do |
|---|
| 1 | Build a transfer in software from patch, pattern, and state data |
Getting Started
From the repository root, configure, build, run tests, then the demo:
cmake -S . -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build -j4
ctest --test-dir build --output-on-failure
./build/po32_demo
Optional, but recommended for local development:
./scripts/install-git-hooks.sh
That enables the repo-managed pre-commit hook, which runs clang-format on
staged .c and .h files before each commit and validates commit subjects
against Conventional Commits. The repo-managed pre-push hook runs the static
analysis script before push.
The demo builds a transfer frame, renders it to audio, decodes it back
(verifying a lossless roundtrip), synthesizes a drum hit, and writes two
WAV files: demo_modem.wav and demo_kick.wav.
Examples
| Command | Purpose |
|---|
./build/po32_example |
Public API
Documentation
Project Layout
Contributing
See CONTRIBUTING.md for local setup, verification commands,
and the Conventional Commits policy used for SemVer-friendly history.
License
Copyright (c) 2026 Eric Lewis. Licensed under the MIT License. See LICENSE.
ericlewis/libpo32
