An Android phone as a Keelson sensor connector.
It reads the phone's GNSS, IMU, barometer, light sensor, battery and radios, publishes them to a
Zenoh router as protobuf wrapped in a Keelson Envelope, and writes the same readings to an MCAP
file on the phone. The two halves are independent — either can be switched off.
No backend of its own, no account, no app store. Point it at a router and press START.
Six screens, in the order a run passes through them. Taken on a Pixel 6; docs/user-guide.md explains each one in words.
 Session — what a run will do, and the button that starts it |
 …and further down it, every subject the phone can publish |
 Live — the chart, and what it says when there is no fix |
 …scrolled past it, the numbers and whether they are keeping up |
 Events — a note, or a quick mark held open as a timer |
 Files — every recording, with its figures and its track |
- 52 Keelson subjects, from 56 streams — position and fix quality, speed, course, heading, attitude and rates, air pressure, light, battery, cellular and Wi-Fi. Audio, time-lapse stills and H.264 video are there too, off by default.
- Records while it publishes. Every sample also goes to a zstd-chunked MCAP file that lands in
Downloads/Logline, readable by Foxglove and keelson's own replayer. - Survives a dropped link. A Zenoh
putsucceeds with no router listening, so the app holds the last couple of minutes of samples and replays them when the router comes back. - Says what happened. Notes and quick marks go on the bus and into the file — tap for an instant, hold for an interval.
- Surveys a platform. Sensor offsets and rotations, measured or typed, published as
frame_transformunder the platform's own entity id. - Runs unattended. A foreground service keeps a run alive with the screen off, through a swipe out of recents, and across a reboot.
You do not need the source to run it. The newest build of main is one link, signed and installable:
https://github.com/RISE-Maritime/Logline/releases/download/main-latest/Logline-main-latest.apk
Open it in the phone's browser, or pick a numbered version from Releases.
Out of the box the endpoint is loopback, tcp/127.0.0.1:7447, so a fresh install publishes nowhere
until it is pointed at a router — a plain tcp/ one on your own network needs nothing else, and a
shared tls/ bus needs three mTLS credentials imported on the phone first. Either way the endpoint
can be typed in, found with Scan for routers, or provisioned from a QR code.
Installing and setting up walks the whole thing, from an empty phone to a recording you can read back.
To build it yourself instead:
export JAVA_HOME="/Applications/Android Studio.app/Contents/jbr/Contents/Home"
./gradlew :app:assembleDebug
adb install -r app/build/outputs/apk/debug/app-debug.apkThis file is the front door; everything else is a page of its own.
| docs/install.md | installing and setting up a phone, from an empty one |
| docs/user-guide.md | using the app — for whoever is handed the phone |
| docs/deploying.md | building, signing, and cutting a release |
| docs/subjects.md | every subject on the wire, and what each number really means |
| docs/keys-and-liveliness.md | the key layout, @v0, and the three liveliness tiers |
| docs/connecting.md | endpoints, mTLS, replay after an outage, proving it works |
| docs/settings.md | what is configurable, checklists, platform library |
| docs/live-view.md | the chart, its layers, and offline maps |
| docs/monitor.md | the Monitor tab: another entity as cards, and why it reads over HTTP |
| docs/recording.md | the MCAP files, and running unattended |
| docs/calibration.md | surveying a platform's geometry, in full |
| docs/architecture.md | how the code fits together |
| docs/development.md | requirements, build, project layout, known limitations |
| CHANGELOG.md | what is in a given build |
| TODO.md · CLAUDE.md | what is pending · how to work on this repo |
Written in Kotlin with Jetpack Compose. Single Gradle module (:app), no backend — it is a publisher
on someone else's bus.