Two routes onto a Pi. The image for a blank card, the script for a board that
already works, which is most of them.
deploy/install.sh installs apt dependencies, clones to /opt/ashvale, builds a
venv with --system-site-packages, enables I2C and installs a systemd unit.
Tested end to end on the real Zero 2 W by installing a second instance on port
8099 alongside the live station: both served, and the live station was
untouched throughout.
That test earned its keep twice. The installer first declared success while the
service was crash-looping on a port clash, because systemd reports active for
the instant between exec and the first failed bind; it now polls the HTTP
endpoint instead, which is the only check that means anything. And my first
attempt to verify that fix was itself worthless, because curl on 127.0.0.1:8000
was answered by the live station rather than the instance under test.
deploy/pi-image is a pi-gen stage on Raspberry Pi OS Lite, Trixie, arm64, which
is exactly what the board runs. Built by .github/workflows/image.yml against a
pinned pi-gen commit, so the artifact does not move when an upstream branch
does, and published to Releases where the 2 GB asset limit comfortably fits a
Lite image.
The image ships no password, no WiFi and no SSH host keys. Baked host keys
would give every person who flashed it the same identity and make them
trivially impersonable on their own network. Coordinates default to Greenwich
at 0 m, wrong for everybody on purpose, because a plausible wrong altitude
quietly biases the sea-level reduction on every row.
The source is copied through a .gitignore filter rather than a hand-written
exclude list, and that is a security property rather than tidiness: the
hand-written list I wrote first missed HANDOVER.md, which is gitignored
precisely because it contains LAN addresses and SSH details. Verified: 69 files,
no state, no local notes, all essentials present.
Auto (follow the system), light, or dark. Auto is a real preference rather than
the absence of one, so it tracks prefers-color-scheme live rather than only at
load. Stored in localStorage, not the station's settings overlay: a theme
belongs to the screen you are reading on, not to the weather station. Control in
the header for one click and in Settings for the explicit three-way choice.
The markup is dark-first Tailwind utilities. Adding a dark: variant to several
hundred class attributes would have been a large diff with a large blast radius,
so light is an overlay that remaps the slate scale and the accent hues under
[data-theme=light]. The dark path is byte-identical: nothing is re-specified
unless the attribute is set.
Chart.js keeps its own copy of every colour and cannot follow a CSS class
change, so the charts read the same tokens from the computed style and are
re-rendered on switch.
Three things the screenshots and measurements caught that reading would not:
- Accent text is the 200-400 shades, picked to glow on black. On white they
wash out. Remapped to the 600-700 shade of the same hue so the colour coding
survives.
- My first remap listed exact class names and silently missed every opacity
variant, because text-amber-200/60 is a different class. Measured at 1.02:1.
Now matched on the hue prefix.
- The value-changed flash is a pale indigo that dropped a headline reading to
2.06:1 on white for half a second, which is precisely when you are looking at
it. Now theme-aware.
Contrast measured with alpha properly composited to the page ground: light 212
nodes below WCAG AA against dark's 208, so light is no worse than the dark
theme it mirrors. The remainder is the design's deliberately quiet tertiary
text, present in both. Layout re-verified: six tabs across three viewports in
both themes, twelve combinations, zero clipping and zero console errors.
Three real faults, all measured rather than guessed.
The forecast chart was unreadable on a 13 inch laptop. A 1280x800 screen has
desktop width but 280 fewer vertical pixels, and the fixed rows (stat cards,
outlook, diagnostics) took that entirely out of the one row meant to flex.
Measured: 404 px tall at 1920x1080, 124 px at 1280x800, 92 px at 1024x768.
Height-aware media queries now compact the furniture instead, and the chart is
201 px at 1280x800.
Mobile navigation did not exist. At 375 px all six tabs were clipped with no
affordance they were there, so five of six sections were unreachable. Below
1024 px the tab row is now a native select on its own full-width line, showing
the current section rather than a bare chevron.
Horizontal overflow on phones: the shell measured 452 px inside a 375 px
viewport. Flex and grid children default to min-width:auto, so a long subtitle
refused to shrink and dragged the layout wider than the screen.
Also restructured the conditions column. It was a fixed stack that simply
overflowed its own card on short screens, and shrinking each piece by media
query chased the symptom; it is now a flex column with exactly one flexible
child, so the tendency chart absorbs the slack and the column fits at any
height. And the no-scroll contract gained a height floor: below 700 px tall the
page scrolls, because at 1024x600 the chart had collapsed to 1 px and a
scrollbar is the better answer.
Verified across ten viewports from 1920x1080 to 375x667, six tabs each: 60
combinations, zero clipping, zero overflow, zero console errors.
Everything that was previously a curl command now has a surface: surroundings,
site geometry, the matrix, the psychrometric flag, and the maintenance actions.
Changes persist to data/state/settings.json, not config.yaml. That file is
hand-annotated and hand-edited per station, and rewriting it from an API would
destroy the comments and risk clobbering something the owner set. The overlay is
applied last in load_config, so a dashboard change beats both the file and the
environment, and deleting the overlay reverts everything. Written atomically via
a temp file so a crash cannot truncate it.
Every field applies live. A settings page that needs a restart is one people
stop trusting, so site geometry is re-read per sample, the compensator flag is
set on the live object, and the display picks up its rate the next frame.
Two deliberate frictions. Selecting a surroundings pill only stages it: nothing
is recorded until you press the button, because that writes a discontinuity
marker and queues a retrain. And changing altitude or the psychrometric flag
says outright that the stored history is now inconsistent and offers the
re-derive, rather than leaving a silent mismatch.
Verified in a browser: pills stage and apply, the toggle round-trips, re-derive
ran 6201 rows in 0.29 s from the button, all six tabs report zero scrollbars and
zero clipping, zero console errors.
New Stats for Nerds tab over a new read-only /api/nerd endpoint: Kalman NIS
and covariance per signal, both compensators, all 18 RLS heads with trace(P)
against the cap, |theta|, EWMA RMSE, conformal alpha against target, realised
coverage and ensemble weights, plus per-head feature attribution over the 33
standardised weights, the Mahalanobis and Page-Hinkley detector state,
climatology harmonics and precipitation coefficients.
Methods overhaul: KaTeX now renders the equations. They were previously passed
through .replace(/[{}\\]/g,' '), which stripped every brace and backslash and
turned real mathematics into mush. Stages 2, 3, 5, 6 and 7 gained full
derivations (RLS normal equations and the trace cap, Joseph-form Kalman with
NIS, adaptive conformal with its coverage limit, ridge harmonic regression with
anomaly decay) and a per-symbol legend rendered inline.
Conditions ahead gains weather icons chosen from measured cloud index, solar
elevation and temperature rather than the barometric class alone, so a fine
barometer under overcast draws a cloud and after sunset draws a moon. Snow is
selected on temperature.
Seven day outlook moves to the top of Live, directly under the nav. Tab renamed
Models and Calibration.
Verified in Chromium at 1600x900: Live, History, Models and Nerd all report
zero scrollbars, zero clipping, no page scroll, zero console errors. Methods
keeps its documented prose scroller. Backtest numerically unchanged.
Seven day outlook moves from History to Live, which now runs four rows.
Conditions ahead tightened so the Live column no longer needs a scroller.
Adds HumidityCompensator: an additive RH offset estimated by one-step RLS from
a trusted hygrometer, clamped to +/-35%, persisted, exposed at
POST /api/calibrate/humidity and on the renamed Models and calibration tab.
It also implements the psychrometric term (RH moved from element temperature
onto air temperature via conserved vapour pressure) but leaves it OFF by
default. The thermal argument predicts a hot element reads low; measured
against a reference hygrometer this board read 75.4% where the truth was
50.4%, so it reads HIGH and that correction would push it the wrong way. When
the flag is enabled, simulate.py applies the exact inverse, per the
simulator/compensator trap in DESIGN.md section 2.
Models pane rebuilt: the scorecard is one column per target so all 18 heads
are visible, and no panel on the tab uses an internal scroller. Verified in
Chromium at 1600x900: Live, History and Models all report zero scrollbars,
zero clipping, no page scroll, zero console errors. Backtest is numerically
identical to the previous commit, confirming the humidity work is a no-op
while the flag is off.
The Live tab now carries the observed-and-forecast chart (a superset of the
old rolling window, which plotted the same observed series without the
prediction) and the precipitation panel. Estimator internals moves to Models,
beside the calibration input that sets the coefficient it reports. The seven
day outlook moves to History. Verified in Chromium at 1600x900: all four tabs
scrollHeight 900 against innerHeight 900, zero clipped elements outside
internal scrollers, zero console errors.
CONTRIBUTING.md now states plainly that this is a solo project: bug reports
welcome, pull requests unlikely to be merged, fork it instead. No other
developer was ever named anywhere in the repository.
kemal