20260906 - Keep listening until the spectrum has something to report

[Purple10101]

The setup wizard's RF scan step almost always printed "0 signals detected". It is not a rendering bug: the measurement array really is empty, and on a fresh container it cannot be anything else.

Why

Two things that only break together.

retina-spectrum suppresses every channel result until it has 5 sweep passes. All per-channel analysis sits behind if (ring.ready()) (src/main.cpp:633), and ready() is count >= METRICS_MIN_ENTRIES, which is 5 (src/config.h:11). Each step's averaging ring gets one push per pass, so passes 1-4 emit "channels":[] in every step event. At roughly 35s a pass that is about 3 minutes of silence by design.

The wizard read one pass and froze. Accumulation ran only between one start and the following complete; on complete the phase became done and the next start was ignored. So the number shown was the channel count of the first full sweep the browser saw, and it never updated however long the user waited.

Entering the location step runs docker compose up -d retina-spectrum, and leaving reverts to radar, which stops and removes the container. Fresh container, empty rings, every time.

It cost more than the label: with no measurements, /towers/search takes its geography-only GET branch, so the RF profile the step exists to collect was never used for ranking.

What changed

static/setup.js only.

• A complete that measured nothing returns the phase to waiting instead of freezing, so the next start re-arms accumulation. It settles on the first pass that actually reports channels.
• spectrumGating still clears after the first completed pass, so Find Towers unlocks at about a minute as before. Waiting longer now improves the profile instead of doing nothing.
• Copy: "Averaging the spectrum, pass N of about 5. Channels appear after about 3 minutes…" while it waits, then "RF profile captured: N channels measured". The old "N signals detected" read as a detection count, but once the ring is ready every TV channel in the step plan is emitted whether or not a pilot was found.

Not fixed here

The 3 minute wait itself is retina-spectrum's METRICS_MIN_ENTRIES = 5 and needs a spectrum release to shorten. The post-completion shortcut at main.cpp:913 also sends a lone complete and closes, which the wizard ignores and then reconnects to every 3s. Harmless while the sweep loop is continuous.

Testing

Deployed to owl-ded9 (88:a2:9e:9d:de:d9) for a live wizard run. Not yet confirmed end to end against a full 5 pass sweep.

🤖 Generated with Claude Code