Sightglass
part of MaracaiboA camera that reads the diesel sight glass, because the tanks predate sensors.
The boat’s fuel tanks are older than the idea of a fuel sensor — but they have a sight glass, and a sight glass can be looked at. So a small camera watches it, a vision model reads the level off the image, and the result publishes as an ordinary MQTT sensor. One safeguard worth stealing: a reading is never shown if the camera and the tank sensors disagree — out-of-sync data is worse than no data.
- One tank read 10% high for weeks. The detector was never wrong.
Sightglass watches the diesel sight tubes on the boat with a camera. Starboard read ~10% high for weeks. I kept tuning thresholds; the…
- A physical invariant is a free hallucination detector
Sightglass is a Raspberry Pi pointing two cameras (via go2rtc) at the diesel sight glasses on my 1967 boat; a vision model reads the fuel…