Teenage Engineering's PO-32 acoustic modem and synth implementation

Summary

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. 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 Decoder Recover normalized frames and packets from transfer audio Drum synthesis Render the PO-32's 21-parameter drum voice locally for preview and testing 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. 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 Pattern packets Which instruments trigger on which steps, with the destination pattern slot encoded as pattern_number State packet Tempo, swing, morph defaults, and the transferred pattern list 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 2 Render that transfer to a WAV or live audio stream 3 Put the PO-32 into its normal receive/import flow 4 Play the rendered transfer audio into the device 5 The PO-32 decodes the packets and writes them to the sound or pattern slots named inside those packets From the repository root, configure, build, run tests, then the demo: cmake -S . -B build -DCMAKE_BUILD_TYPE=Rel...