Operator's household environment showed CSI-variance presence detection
failing — empty room produced HIGHER variance than an occupied room because
ambient WiFi noise (neighbour APs, retransmits, BT-coex) dominated the
broadband-variance signal at multi-meter range.
Deployed a TP-Link TL-WR841N in WISP mode as a dedicated isolated AP for
the sensors:
* Sensors associate only with TP-Link_8340 (clean channel)
* TP-Link bridges to the household AP, NAT-forwards sensor UDP to the Mac
* Mac keeps its primary household-AP association — no LAN reconfig needed
* Empty-room variance dropped 50.7 → 35.8 (-30%)
Replaced presence classification with RSSI MAD-Δ override:
* Per-node rolling 120-sample (~10 s @ 12 Hz) window of frame RSSI
* Metric: mean(|Δrssi|) between consecutive frames — robust to int8
quantisation jitter
* Thresholds tuned for the operator's geometry:
d < 0.20 → absent
< 0.55 → present_still
< 1.10 → present_moving
>= 1.10 → active
* Confidence field temporarily carries raw d for in-field threshold tuning
* CSI-based features (variance, motion_band_power, spectral_power) remain
in features.* for vital-sign signal-quality and multi-node fusion paths
UI / tooling:
* New static/spectrum.html — live signal console: combined classification,
all host-computed features (variance, motion_band, spectral, breathing
band, RSSI, dominant_freq, change_points), per-node FW signals, and a
60-second variance trace. Served via `python -m http.server 8091`.
* static/calibrate.html — simpler per-node motion/presence/RSSI bars
with peak-hold.
Desktop UI / discovery hardening (rolled in here because they came up
during this debug session):
* commands/discovery.rs: HTTP sweep limited to 2..=60 hosts (was 1..=254),
mDNS + UDP-broadcast paths disabled (current RuView FW doesn't advertise
them and they were burning CPU every poll cycle). Per-request timeout
set to 1500 ms with overall budget enforced via tokio::time::timeout +
futures::join_all (replaces the previous sequential select loop that
blocked on slow IPs).
* ui/hooks/useNodes.ts: poll interval 10 s → 30 s.
* ui/pages/Dashboard.tsx + NetworkDiscovery.tsx: merge new scan results
into existing list instead of replacing — discovery races sometimes miss
a node that was found a moment ago.
Firmware tuning:
* edge_processing.c: broadband-variance divisor /3.0 → /30.0 → /5.0
iterated; final /5.0 chosen for multi-meter geometry (sensor 1-3 m
from activity zone). DEBUG_MOTION_DSP scaffolding removed.
* csi_collector.c: CSI_MIN_SEND_INTERVAL_US 20 ms → 4 ms so the host can
see every available frame (real ceiling is the WiFi CSI callback rate).
Documentation:
* docs/adr/ADR-099 — full forensic write-up: measurement tables for sit/
walk/empty, the RSSI-Δ rationale, the WISP setup procedure, calibration
protocol for new deployments, and open items.
Verified end-to-end on hardware (sensors at 192.168.1.17/.19 → TP-Link at
192.168.1.14 → Mac at 192.168.1.21):
* UDP/5006 packets arrive ~12 Hz combined from both nodes
* Empty-room baseline d ≈ 0.49 measured (next: capture sit + walk to
finalize thresholds)
* Vital signs continue to populate (breathing 9–11 BPM stable)
* Two consecutive OTA round-trips remain functional after the change
Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
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