This is how I configured my Omi DevKit: it records only after I press the button, captures locally to the SD card, and syncs later. No always-on microphone, no ambient listening. Tap to start, tap to stop.
It turned out to be great for offline walks. I press the button, think out loud, and the audio is waiting on the device. When I am back at my desk it syncs and runs through transcription. Privacy stays simple because nothing is recorded unless I deliberately start it.
This repository is a public showcase of the part that is useful to others: the firmware patch that turns the DevKit into a reliable press-to-record, SD-first capture device. The host-side sync that pulls audio off the device is personal to my setup and is not included here, and no recordings or transcripts are part of this repo.
The stock firmware streams continuously. My build flips that around:
- Press to start, press to stop. A single button press begins a recording session, another ends it. The device is silent in between.
- SD card is the source of truth. Audio is written to the SD card first, so a dropped connection never loses a session.
- Resilient sessions. Each recording is a self-contained session on disk, with an automatic stop safeguard so a forgotten session does not run the battery flat.
- Quiet operation. An optional silent build with the haptic and speaker disabled, for unobtrusive capture on a walk.
firmware/: the patched DevKit firmware.devkit/: the modified source, with the button and capture logic.BUILD_RECIPE.md: how to build it (NCS toolchain).prebuilt/: prebuilt.uf2images you can flash directly.
HANDOVER.md: notes from the build, including the SD-card debugging journey.
The host integration (pulling sessions off the SD card, queueing them for transcription) lives in my private system and is intentionally left out, since it is wired to personal infrastructure.
The prebuilt/ directory contains ready-to-flash .uf2 images. Put the DevKit into bootloader mode and copy the image across, or follow firmware/BUILD_RECIPE.md to build your own. This is an unofficial modification, so flash at your own risk and keep a copy of the stock firmware.
The whole point of this configuration is consent-first capture: the microphone is off until you press the button. This repository contains firmware and build notes only. No audio, transcripts, or personal data are included.