Field Notes · IIoT · Industrial controls
Dispatches from the intersection of industrial control systems, IIoT architecture, and biolab experiments. These are the notes I wish existed when I was debugging SCADA at 2 am — written close to the metal, after the hardware answers back.
Field Notes from a Bioreactor — read the series in order →
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The Pioreactor Rebooted and Broke the Circadian Clock
A hardware watchdog silently rebooted the Pioreactor mid-afternoon, killing the grow light for fifteen minutes and nearly re-anchoring the culture’s circadian clock eight hours off schedule. Here’s the forensics on a 5.20V under-voltage fault, the restore that almost…
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The Pioreactor Was Cooking Its Own Culture
For a month I called the Pioreactor’s heat an external given — the garage in August, a reactor with no cooling side. A 96-hour diagnostic proved me wrong: the vessel’s overnight floor never falls, the evening peak lands…
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The Culture Refused to Stay Dead — OD Rose Again
I called the culture dead last week from four days of flat OD. It wasn’t flat — it was climbing all along, +16% over ten days under lethal heat. Here’s how I tested whether that rise is real…
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The Science of the Silence — What the Literature Says About Pyrocystis at 30°C
Two weeks of nightly NULL flashes and we suspected the camera. The literature says otherwise: bioluminescent dinoflagellates lose their flash above 27°C, and our vessel has spent every day since Aug 11 inside that critical zone. What the…
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Three Numbers and a Float Switch: Instrumenting a Fish Tank
An ESP32 reading pH, dissolved solids and temperature off a tank — with three-point probe calibration exposed as Home Assistant buttons, and TDS temperature-compensated so the reading means something.
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The Meter Was Already Broadcasting: Reading Gas Usage Off the Air
A $30 software-defined radio, an antenna, and an SCM+ decoder — reading the number a utility meter already shouts over 900 MHz several times an hour, instead of photographing its dials. Protocol notes and the current state of…
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One Beam, 1200 Points: Drawing What a Camera Sees With a Laser
A laser projector has one beam and no frame buffer — everything you see is the path two mirrors traced in the last fortieth of a second. Pointing a camera at the world and drawing what it sees…
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Feet Per Standard Deviation: Building a Disc Golf Coach for My Dad
A smart disc records fifty-three fields per throw and tells you almost nothing. The pipeline that turns them into coaching — Firestore behind App Check, percentile tables built from 18,527 pro tournament throws, a standardized regression, a bootstrapped…
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The Culture Stopped Growing — Heat Wins a Round
For five days the vessel has not touched its safe temperature band once. This week the optical density finally went flat, and a proven-working camera confirmed the nightly glow captures are real nulls, not sensor failure. Three instruments,…
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Trusting a Null: Proving the Glow Camera Works
A positive control settles the six-night NULL mystery: the glow-capture pipeline works end-to-end, which means the missing bioluminescence is real data about the culture, not an instrument failure. Notes on why a null is only meaningful once you’ve…
New posts are infrequent — when something worth writing happens in the lab or the rack room.