docs(spec): document server-push runtime tuning in design spec

Reflects the feature shipped on this branch: backend can push per-device
CV tuning in the heartbeat response, device validates + persists to NVS.
Removes the stale line_offset row from the operator-provisioning table
(moved into CVTuning, server-managed).

Also adds .agent/, firmware/.pio/, and graphify-out/ to .gitignore so
local working dirs and build artifacts don't get accidentally tracked.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

.gitignore

@@ -1,6 +1,4 @@
 .worktrees/
 .agent/
-.claude/
-graphify-out/
 firmware/.pio/
-*.log
+graphify-out/

README.md

@@ -1,8 +1,6 @@
 # DoorCounter
 
-Retail door traffic counter using M5Stack TimerCamera-F (ESP32 + OV3660). Counts walker traversals via overhead camera CV, passively scans BLE foot traffic, and reports hourly to `logs.research.bike`.
-
-> **Known limitation — directional accuracy.** This firmware reports counts as `{entries, exits}` for API compatibility, but **per-walk direction labelling is not reliable at the current mount (7' overhead, straight down).** In bench testing, event detection was 100% (8/8 walks detected) while per-walk direction matched the physical walk only ~50% of the time — the centroid trajectories produced by entries and exits were nearly indistinguishable. **The number to trust is gross traffic: `entries + exits` ≈ total walkers through the doorway.** The directional split is an unreliable best-effort heuristic. See [Directional counting](#directional-counting) for why.
+Retail door traffic counter using M5Stack TimerCamera-F (ESP32 + OV3660). Counts entries/exits via overhead camera CV, passively scans BLE foot traffic, and reports hourly to `logs.research.bike`.
 
 ## Hardware
 
@@ -23,8 +21,7 @@ pio run -t upload --upload-port /dev/ttyUSB0
 
 | Module | Behavior |
 |--------|----------|
-| CV pipeline | 5 fps, 96×96 grayscale, event-based walker detector (foreground-count state machine; centroid-trajectory direction heuristic) with post-fire refractory period |
-| Detection LED | Single blink on entry, double blink on exit (preserves upload/no-WiFi status LED) |
+| CV pipeline | 5 fps, 96×96 grayscale, blob tracking, line-crossing count |
 | BLE scanner | Continuous passive scan; deinits during hourly upload to free heap |
 | Reporter | Hourly HMAC-signed POST; 60s boot report for fast connectivity check |
 | Provisioning | Captive portal AP on first boot for WiFi setup |
@@ -35,71 +32,6 @@ pio run -t upload --upload-port /dev/ttyUSB0
 - **First report**: 60 seconds after NTP sync (connectivity check)
 - **Subsequent reports**: every 3600 seconds
 
-### Counting model — event-based walker detector
-
-The CV pipeline is a **single event state machine** (no per-blob tracking
-for counting). Per-frame foreground pixel count gates event start and end;
-centroid trajectory within the active event decides direction.
-
-**Event lifecycle:**
-1. **Idle → Active**: `fg_count ≥ CV_EVENT_ENTER_THRESH` (250 px) fires event start.
-   Background updates freeze while the event is active so the walker does
-   not get absorbed into the baseline.
-2. **Active accumulation**: every frame updates `first_c` (once), `min_c`,
-   `max_c`, `last_c`, `min_y_seen`, `max_y_seen`, and the frame count.
-3. **Active → End** (either):
-   - **Quiet exit**: `fg_count < CV_EVENT_EXIT_THRESH` (150 px) for
-     `CV_EVENT_QUIET_FRAMES` (3) consecutive frames — walker has left.
-   - **Timeout**: `event_frame_count > CV_EVENT_MAX_FRAMES` (25 frames ≈ 5s).
-4. On end, the event is finalized: gated by minimum duration, vertical
-   extent (must span a large fraction of the frame), and minimum centroid
-   trajectory magnitude. Background snaps to the current frame.
-5. A **refractory period** (`CV_EVENT_REFRACTORY_FRAMES` = 10 ≈ 2s) after
-   a fire blocks a new event from starting — absorbs residual lingering
-   motion that would otherwise double-count.
-
-**Direction heuristic** (applied only if the event passes all gates):
-- `up_score   = first_c − min_c` (how far centroid excursed upward)
-- `down_score = max_c   − first_c` (how far it excursed downward)
-- Quiet-exit events: `is_entry = (up_score ≥ down_score)`
-- Timeout events: `is_entry = (last_c < first_c)` — net displacement is
-  more reliable than excursion when the walker is still in frame at timeout.
-
-Per-mount convention: centroid moving **up through the frame** (y decreasing)
-= **entry** into the store.
-
-### Directional counting — known limitation
-
-**Per-walk direction labelling is unreliable at the current mount.** In
-bench testing (8 alternating entry/exit walks at 4s intervals, 7' overhead
-mount pointing straight down):
-
-- **Event detection**: 8/8 (100%) — every walk produced exactly one event.
-- **Aggregate split**: 4 entries + 4 exits — matches the 4+4 ground truth.
-- **Per-walk direction**: 4/8 (50%) — essentially a coin flip.
-
-At this mount, entries and exits produce nearly identical centroid
-trajectories: both begin near mid-frame (walker is already large when
-`fg_count` crosses 250), both reach a peak excursion toward the top, and
-both end near mid-frame (walker's tail is still visible when `fg_count`
-drops below 150). No heuristic over the recorded centroid statistics
-separates them with better than ~50% accuracy on alternating walks.
-
-**What we ship, and what the server should trust:**
-- **Gross traffic (`entries + exits`) is accurate.** This is the number
-  downstream analytics should use as "people through the door this hour."
-- **Directional split is reported but unreliable.** Treat individual
-  `entries` and `exits` values as a best-effort labelling. Do not infer
-  net flow or dwell from them.
-
-To actually recover per-walk direction would require either a physical
-change (raise or tilt the camera so walkers enter/leave through the frame
-edges) or a richer signal than centroid statistics (e.g. time-resolved
-optical flow, or a second sensor). That work is out of scope for v1.
-
-See `firmware/lib/cv/cv.h` for tuning constants and `cv.cpp` for the
-finalize logic.
-
 ## Operator Setup
 
 ### 1. Flash firmware
@@ -123,12 +55,6 @@ python tools/flash_device.py \
 
 WiFi credentials are optional — if omitted, device starts captive portal on boot.
 
-> **Re-provision after firmware uploads.** Flashing firmware via
-> `pio run -t upload` may clear the NVS partition on this board. If the device
-> boots into a ~1 Hz LED blink (the "not provisioned" fatal state) after a
-> firmware update, re-run `flash_device.py` with the same credentials. See
-> [Troubleshooting](#troubleshooting).
-
 ### 3. OTA updates
 
 ```bash
@@ -144,7 +70,7 @@ python tools/ota_push.py \
 3. Connect phone to `DoorCounter-Setup` WiFi
 4. Browser opens automatically → enter store WiFi password → done
 
-**LED indicators**: Red = no WiFi · Blue = counting · Yellow = uploading · Brief flash (×1) on entry · Brief flash (×2) on exit
+**LED indicators**: Red = no WiFi · Blue = counting · Yellow = uploading
 
 ## API
 
@@ -158,15 +84,72 @@ Endpoint: `http://logs.research.bike`
 
 All requests are HMAC-SHA256 signed. See [design spec](docs/superpowers/specs/2026-04-13-door-counter-design.md) for full API shapes and auth scheme.
 
+## Runtime Configuration
+
+The backend can push CV tuning parameters to individual devices in the response to `POST /api/v1/heartbeat`. No HTTP server runs on the device — updates ride the existing outbound, HMAC-authenticated channel.
+
+### Configurable fields
+
+| Field | Type / Range | Meaning |
+|-------|--------------|---------|
+| `cfg_version` | uint32, non-zero | Monotonic version; device ignores updates with version ≤ stored. |
+| `diff_thresh` | 5–120 | Per-pixel motion threshold; higher = less sensitive. |
+| `min_blob_px` | 16–4096 | Minimum connected foreground pixels to count as a blob; higher = fewer false positives from small motion. |
+| `max_move` | 2.0–50.0 | Max inter-frame track displacement, in pixels on the 96×96 frame. |
+| `max_missed` | 1–60 | Frames a track can be missed before dropped. |
+| `line_offset` | 0–100 | Virtual counting line, as percent of frame height. |
+
+### Push flow
+
+The heartbeat response MAY include a `config` object. All fields except `cfg_version` are optional; missing fields retain the device's current value.
+
+```json
+{
+  "config": {
+    "cfg_version": 7,
+    "diff_thresh": 25,
+    "min_blob_px": 200,
+    "max_move": 12.0,
+    "max_missed": 8,
+    "line_offset": 55
+  }
+}
+```
+
+### Validation and apply rules
+
+- Missing response body, non-200, malformed JSON, or missing `config` object → silent no-op.
+- Missing `cfg_version` → rejected, logged `[CFG] missing cfg_version`.
+- `cfg_version` ≤ stored → rejected as stale, logged.
+- Any present field with wrong JSON type → whole update rejected, logged `[CFG] rejected malformed config`.
+- Any field out of range → whole update rejected, logged `[CFG] rejected invalid config`.
+- Valid update → applied atomically under mutex, persisted to NVS, logged `[CFG] applied v=N`.
+
+### Persistence
+
+Tuning is stored in the `doorcounter` NVS namespace and survives reboot. On boot, the device loads the persisted values; if none present, compiled defaults apply.
+
+### Trust model
+
+The reporting channel is plain HTTP today. The HMAC scheme signs only outbound **requests** (method + path + timestamp + sha256(body)) — it does not authenticate response bodies. A network attacker with access to the customer LAN can rewrite a heartbeat response and push any config that passes the device's range validator (`diff_thresh` 5–120, `min_blob_px` 16–4096, `max_move` 2.0–50.0, `max_missed` 1–60, `line_offset` 0–100). The validator is the last line of defense: malicious-but-in-range pushes can still degrade counting (e.g., `min_blob_px = 16` makes the detector noisy).
+
+Per-device targeting (keyed by `device_id`) still works correctly and is unaffected by the integrity gap — each device only applies updates addressed to itself.
+
+Operators should treat customer LANs as untrusted and rely on monitoring heartbeat cadence and count anomalies to detect tampering. No inbound HTTP surface is exposed on customer LANs by design — the device only makes outbound requests.
+
+## Roadmap
+
+**Gated local config portal.** Holding the BOOT button for ~3 seconds would raise a WiFiManager-style captive portal on the local network for ~5 minutes, exposing a tuning page for field techs operating without backend connectivity. Deferred because (a) the server-push mechanism above covers routine tuning, (b) an always-on HTTP server on customer LANs is an undesirable attack surface, and (c) the gated-by-physical-access model needs additional auth design to be safe.
+
+**Authenticated config push.** Move reporting to HTTPS, or include a signed envelope on pushed config (e.g., `config_sig = HMAC(secret, cfg_version || canonical_json(config))` verified on device) so pushed tuning is tamper-evident over plain HTTP.
+
 ## Project Structure
 
 ```
 DoorCounter/
 ├── firmware/
 │   ├── platformio.ini
-│   ├── lib/
-│   │   ├── cv/            — CV pipeline (event state machine, centroid-trajectory direction)
-│   │   └── hmac/          — HMAC-SHA256 signing library
+│   ├── lib/hmac/          — HMAC-SHA256 signing library
 │   └── src/
 │       ├── main.cpp       — FreeRTOS tasks, boot sequence
 │       ├── config.*       — NVS read/write
@@ -176,24 +159,8 @@ DoorCounter/
 │       └── reporter.*     — hourly batch POST + local buffer
 ├── tools/
 │   ├── flash_device.py    — NVS provisioning script
-│   ├── ota_push.py        — OTA push script
-│   └── serial_monitor.py  — reset + read serial with timestamps (diagnostic)
-├── docs/
-│   ├── server-prompt-crossing-cooldown.md — server-side coordination notes
-│   └── superpowers/specs/2026-04-13-door-counter-design.md
+│   └── ota_push.py        — OTA push script
+├── docs/superpowers/specs/
+│   └── 2026-04-13-door-counter-design.md
 └── server/                — API server (separate deployment)
 ```
-
-## Troubleshooting
-
-| Symptom | Likely cause | Remedy |
-|---------|--------------|--------|
-| ~1 Hz LED blink after boot, no serial beyond `esp_core_dump_flash: No core dump partition found!` | NVS missing `device_id` / `location_id` / `hmac_secret`. Commonly triggered by a firmware upload wiping NVS. | Re-run `flash_device.py` with the device's known credentials. |
-| Device stays on `DoorCounter-Setup` AP instead of joining customer WiFi | SSID/password in NVS wrong, or network out of range. | Connect phone to `DoorCounter-Setup` → captive portal → re-enter WiFi. Or reflash NVS with correct `--wifi-ssid` / `--wifi-password`. |
-| No entries/exits counted for a known-walking doorway | WiFi captive portal still up (camera task starts only after connect); or camera blocked/unfocused. | Check LED: solid on = booting/uploading, off = counting. Run `serial_monitor.py` to see `[CV] entry/exit` log lines. |
-
-Capture a boot log with timestamps:
-
-```bash
-python tools/serial_monitor.py --port /dev/ttyUSB0 --reset --timestamp --seconds 30
-```

docs/server-prompt-crossing-cooldown.md

@@ -1,78 +0,0 @@
-# Server-Side Prompt — Crossing Cooldown Awareness
-
-> Give this to your server-side agent after the firmware commit that introduces
-> `CV_CROSSING_COOLDOWN_FRAMES` in `firmware/lib/cv/cv.h` has been flashed to devices.
-
-## Context
-
-The DoorCounter firmware now enforces a **per-direction crossing cooldown** in
-its CV pipeline. After a counted entry, subsequent entries within 5 frames
-(~1 second at 5 fps) are silently dropped on-device. Exits follow the same
-rule independently. This is a device-side fix for the known track-churn bug
-(single person producing 5+ counts per visit when their blob briefly drops
-below the minimum-blob-pixel threshold).
-
-Constants live in `firmware/lib/cv/cv.h`:
-
-```c++
-static const uint32_t CV_CROSSING_COOLDOWN_FRAMES = 5; // per-direction
-```
-
-Cooldown is **fixed at compile time**. It is **not** currently a server-
-pushable tuning parameter.
-
-## What the server should do
-
-1. **Expect lower per-hour entry/exit counts** from devices running this
-   firmware compared to their historical baseline. This reflects suppression
-   of false positives, not a device regression. Do not alert on the drop.
-
-2. **If you have a per-device tuning-config push mechanism** (the one planned
-   in `.agent/plan.md` — server-push CV config via heartbeat response), add
-   `cooldown_frames` to the sendable tuning set with:
-   - Default: `5`
-   - Valid range: `0..60` (0 disables cooldown; 60 ≈ 12s at 5 fps)
-   - Semantics: per-direction, applied to both entries and exits
-   - Persist alongside other CV tuning keys in NVS under a new key `cv_cool`.
-   - Bump the `cfg_version` scheme accordingly.
-
-   **Do not ship this server-side change yet** — the firmware change in this
-   commit keeps the cooldown as a compile-time constant. A future firmware
-   commit on `feature/server-push-config` will expose it as a runtime
-   tunable and bump `cfg_version`. Coordinate the rollout: firmware first,
-   then server.
-
-3. **Dashboard**: if you render device CV parameters in a per-device settings
-   view, add a read-only row "Crossing cooldown (frames): 5" sourced from
-   the firmware's compiled default. Mark it editable only once the firmware
-   exposes it as a tunable.
-
-4. **Telemetry (optional, low priority)**: consider adding a field
-   `suppressed_crossings_delta` to the heartbeat or camera-events payload
-   so operators can see how often cooldown is kicking in. This would require
-   a firmware change; flag it as future work only if churn continues.
-
-## What NOT to do
-
-- Do not attempt to push `cooldown_frames` via the existing config channel
-  today — the firmware will ignore unknown fields, which is fine, but
-  shipping server changes that assume the firmware-side plumbing exists
-  will break the integration contract.
-- Do not "correct" the lower counts via server-side multiplication. The
-  cooldown is the correct behavior; old counts were inflated by the churn
-  bug.
-
-## Verification checklist
-
-- [ ] Historical counts chart annotated with "firmware v{N} deployed"
-      marker on the rollout date.
-- [ ] Per-device tuning view renders cooldown row (read-only for now).
-- [ ] No alert fires on the per-device count drop post-rollout.
-
-## Reference
-
-- Firmware change: `firmware/lib/cv/cv.h` (`CV_CROSSING_COOLDOWN_FRAMES`),
-  `firmware/lib/cv/cv.cpp` (suppression logic in `cv_process`).
-- Design spec: `docs/superpowers/specs/2026-04-13-door-counter-design.md`
-  § 3.1 "Counting logic".
-- Unit test: `firmware/test/test_cv/test_cv.cpp::test_cooldown_suppresses_rapid_re_entry`.

docs/superpowers/specs/2026-04-13-door-counter-design.md

@@ -12,8 +12,8 @@
 ```
 [TimerCamera-F Device]
   ├── Provisioning module   — captive portal AP on first boot
-  ├── Config store          — NVS: device_id, location_id, HMAC secret, WiFi creds, line_offset
-  ├── Camera + CV module    — captures frames, runs event-based walker detector
+  ├── Config store          — NVS: device_id, location_id, HMAC secret, WiFi creds, CV tuning (server-pushed)
+  ├── Camera + CV module    — captures frames, runs line-crossing counter
   ├── BLE scanner           — continuous passive scan (WiFi coexistence mode)
   ├── Report buffer         — accumulates counts in RAM, flushes hourly
   └── HTTP client           — HMAC-signed POSTs to logs.research.bike
@@ -65,7 +65,12 @@ Writes directly to NVS over serial. WiFi credentials are optional — if omitted
 | `hmac_secret` | Operator      | Yes                 |
 | `wifi_ssid`   | User/operator | Yes                 |
 | `wifi_pass`   | User/operator | Yes                 |
-| `line_offset` | Default 50%   | No                  |
+
+CV tuning (`cv_diff`, `cv_blob`, `cv_move`, `cv_miss`, `cv_line`, `cv_ver`) lives in the same namespace but is set at runtime by the backend via heartbeat-response push — see §2.1. On first boot with no pushed config, compiled defaults apply.
+
+### 2.1 Runtime tuning (server push)
+
+The backend may include a `config` object in the `POST /api/v1/heartbeat` response to update per-device CV parameters. The device validates, persists to NVS, and applies atomically under mutex. Stale (`cfg_version ≤ stored`), malformed, or out-of-range updates are rejected. See `README.md` → "Runtime Configuration" for the full wire contract, field ranges, and trust-model caveat (plain HTTP; HMAC signs requests only).
 
 ### Factory reset
 
@@ -89,38 +94,15 @@ Capture → Grayscale → Downscale 96×96 → Frame diff → Threshold → Blob
 | Downscale | Bilinear to 96×96 (~11× compute reduction) |
 | Frame diff | Absolute difference against rolling background (updated every ~2s when no motion) |
 | Threshold | Pixels > 30 intensity delta = foreground |
-| Event state machine | Single global state machine (not per-blob). Per-frame `fg_count` (total foreground pixels) gates event start and end. |
-| Event start | `fg_count ≥ CV_EVENT_ENTER_THRESH` (250 px) → event becomes active. Background updates freeze for the event's duration so the walker does not blend into the baseline. |
-| Event accumulation | Each frame records `first_c` (centroid_y at start), running `min_c` / `max_c` / `last_c`, vertical extents (`min_y_seen`, `max_y_seen`), and frame count. |
-| Event end | Either **quiet exit** (`fg_count < CV_EVENT_EXIT_THRESH` (150 px) for `CV_EVENT_QUIET_FRAMES` (3) consecutive frames) or **timeout** (`event_frame_count > CV_EVENT_MAX_FRAMES` (25)). On end, background snaps to the current frame. |
-| Fire gates | Duration ≥ `CV_EVENT_MIN_FRAMES` (5), `min_y_seen ≤ CV_EVENT_EXTENT_TOP` (25) AND `max_y_seen ≥ CV_EVENT_EXTENT_BOT` (50) — event must span a large fraction of the frame — AND `max(up_score, down_score) ≥ CV_EVENT_MIN_TRAJ` (5) |
-| Refractory | `CV_EVENT_REFRACTORY_FRAMES` (10 ≈ 2s) after a fire, the machine refuses to start a new event — absorbs lingering motion of the just-counted walker. |
+| Blob detect | Connected components; blobs < 8×8 px discarded as noise |
+| Centroid track | Nearest-centroid matching frame-to-frame (max 15px), tracks persist up to 10 missed frames |
+| Line crossing | Virtual horizontal line at configurable vertical position (default: 50% of frame height) |
 
-**Direction heuristic (applied after fire gates pass):**
-- `up_score   = first_c − min_c` (peak upward centroid excursion)
-- `down_score = max_c   − first_c` (peak downward centroid excursion)
-- **Quiet-exit fires**: `is_entry = (up_score ≥ down_score)`
-- **Timeout fires**: `is_entry = (last_c < first_c)` — walker is still in frame at timeout, so net displacement is a better signal than excursion.
+**Counting logic:**
+- Centroid crosses line top→bottom = **entry**
+- Centroid crosses line bottom→top = **exit**
 
-Per-mount convention: centroid moving **up through the frame** (y decreasing) = **entry** into the store.
-
-**Counting surface**: `{entries, exits}` accumulate in RAM and reset each hour on report.
-
-**Directional accuracy is best-effort, not guaranteed.** In bench testing at the intended 7' overhead straight-down mount:
-
-| Metric | Result |
-|--------|--------|
-| Event detection | 8/8 walks (100%) |
-| Aggregate entry/exit split | 4+4 vs ground-truth 4+4 (matches) |
-| Per-walk direction labelling | 4/8 (50%) — no better than chance |
-
-At this mount, entries and exits produce nearly identical centroid trajectories: the walker is already large when `fg_count` crosses 250 (so `first_c` is always near mid-frame), their tail is still visible when `fg_count` drops below 150 (so `last_c` is always near mid-frame), and the excursion in between peaks upward for both directions. No statistic computable from (`first_c`, `min_c`, `max_c`, `last_c`, duration) separates them reliably.
-
-**Contract with downstream consumers (API and analytics):**
-- **`entries + exits` is the trustworthy number** — it is the count of walkers through the doorway in the hour. Use this as "foot traffic."
-- **Individual `entries` and `exits` are reported for API shape compatibility, but should not be relied on for net flow, dwell, or any per-direction analysis.**
-
-Recovering true direction requires either a physical change (tilt or raise the camera so walkers pass fully through the frame edges) or a richer signal (time-resolved centroid trajectory, optical flow, secondary sensor). Both are out of scope for v1.
+Counts accumulate as `{entries, exits}` in RAM and reset each hour on report.
 
 ---
 

firmware/lib/cv/cv.cpp

@@ -5,21 +5,16 @@
 #include <algorithm>
 #include <vector>
 
-static void event_reset(CVState& s) {
-    s.event_active       = false;
-    s.event_start_frame  = 0;
-    s.event_frame_count  = 0;
-    s.event_peak_n       = 0;
-    s.event_first_c      = -1.0f;
-    s.event_last_c       = -1.0f;
-    s.event_min_c        = (float)CV_H;
-    s.event_max_c        = -1.0f;
-    s.event_min_y_seen   = CV_H;
-    s.event_max_y_seen   = -1;
-    s.event_quiet_count  = 0;
-}
+// File-local defaults. Runtime values live in CVState::tuning and can be
+// overridden via config_load_tuning() on boot or server push at runtime.
+static constexpr uint8_t CV_DEFAULT_DIFF_THRESH = 30;
+static constexpr int     CV_DEFAULT_MIN_BLOB_PX = 64;
+static constexpr float   CV_DEFAULT_MAX_MOVE    = 15.0f;
+static constexpr int     CV_DEFAULT_MAX_MISSED  = 10;
+static constexpr uint8_t CV_DEFAULT_LINE_OFFSET = 50;
 
 void cv_init(CVState& state) {
+    // Initialize members directly — avoid CVState{} temporary which puts 9KB on stack
     memset(state.background, 0, sizeof(state.background));
     state.bg_valid          = false;
     state.last_motion_frame = 0;
@@ -28,8 +23,12 @@ void cv_init(CVState& state) {
     state.tracks.clear();
     state.entries = 0;
     state.exits   = 0;
-    state.last_fire_frame = 0;
-    event_reset(state);
+    state.tuning.diff_thresh = CV_DEFAULT_DIFF_THRESH;
+    state.tuning.min_blob_px = CV_DEFAULT_MIN_BLOB_PX;
+    state.tuning.max_move    = CV_DEFAULT_MAX_MOVE;
+    state.tuning.max_missed  = CV_DEFAULT_MAX_MISSED;
+    state.tuning.line_offset = CV_DEFAULT_LINE_OFFSET;
+    state.tuning.cfg_version = 0;
 }
 
 void cv_reset_counts(CVState& state) {
@@ -37,9 +36,23 @@ void cv_reset_counts(CVState& state) {
     state.exits   = 0;
 }
 
+bool cv_tuning_validate(const CVTuning& t) {
+    if (t.cfg_version == 0) return false;
+    if (t.diff_thresh < 5   || t.diff_thresh > 120)  return false;
+    if (t.min_blob_px < 16  || t.min_blob_px > 4096) return false;
+    if (t.max_move    < 2.0f || t.max_move   > 50.0f) return false;
+    if (t.max_missed  < 1   || t.max_missed  > 60)   return false;
+    if (t.line_offset > 100)                         return false; // uint8, min 0
+    return true;
+}
+
 struct Point { int x, y; };
 
-static std::pair<float,float> extract_blob(uint8_t* fg, int start_x, int start_y) {
+// Note: queue may grow to CV_PIXELS entries (~72KB) on large blobs.
+// Requires PSRAM (enabled via -DBOARD_HAS_PSRAM in platformio.ini).
+// BFS flood fill. Marks visited pixels (sets fg to 0). Returns {-1,-1} if blob < min_blob_px.
+static std::pair<float,float> extract_blob(uint8_t* fg, int start_x, int start_y,
+                                           int min_blob_px) {
     std::vector<Point> queue;
     queue.reserve(512);
     queue.push_back({start_x, start_y});
@@ -64,19 +77,20 @@ static std::pair<float,float> extract_blob(uint8_t* fg, int start_x, int start_y
         }
     }
 
-    if (count < CV_MIN_BLOB_PX) return {-1.0f, -1.0f};
+    if (count < min_blob_px) return {-1.0f, -1.0f};
     return {sum_x / count, sum_y / count};
 }
 
-static std::vector<std::pair<float,float>> find_centroids(const uint8_t* fg) {
+static std::vector<std::pair<float,float>> find_centroids(const uint8_t* fg,
+                                                          int min_blob_px) {
     std::vector<std::pair<float,float>> result;
-    static uint8_t fg_copy[CV_PIXELS];
+    static uint8_t fg_copy[CV_PIXELS];  // static to avoid 9KB stack allocation
     memcpy(fg_copy, fg, CV_PIXELS);
 
     for (int y = 0; y < CV_H; y++) {
         for (int x = 0; x < CV_W; x++) {
             if (!fg_copy[y * CV_W + x]) continue;
-            auto c = extract_blob(fg_copy, x, y);
+            auto c = extract_blob(fg_copy, x, y, min_blob_px);
             if (c.first >= 0) result.push_back(c);
         }
     }
@@ -84,70 +98,16 @@ static std::vector<std::pair<float,float>> find_centroids(const uint8_t* fg) {
 }
 
 static void frame_diff(const uint8_t* frame, const uint8_t* bg,
-                       uint8_t* fg, int pixels) {
+                       uint8_t* fg, int pixels, uint8_t diff_thresh) {
     for (int i = 0; i < pixels; i++) {
         int diff = (int)frame[i] - (int)bg[i];
         if (diff < 0) diff = -diff;
-        fg[i] = (diff > CV_DIFF_THRESH) ? 1 : 0;
+        fg[i] = (diff > diff_thresh) ? 1 : 0;
     }
 }
 
-// Decide whether the just-ended event should fire and in which direction.
-// Up-through-frame (centroid excursion from high y toward low y) maps to
-// ENTRY per mount convention.
-static void finalize_event(CVState& s, CVResult& result) {
-    if (s.event_frame_count < CV_EVENT_MIN_FRAMES) return;
-    // Note: no MAX_FRAMES rejection here. An event that runs the full duration
-    // may still be a valid walker whose fg_count stayed above EXIT_THRESH due
-    // to a stale bg or an AEC-driven lighting shift. Extent + MIN_TRAJ gates
-    // below already reject stationary-person / wobble events.
-    if (s.event_min_y_seen > CV_EVENT_EXTENT_TOP)  return;
-    if (s.event_max_y_seen < CV_EVENT_EXTENT_BOT)  return;
-
-    // Direction from centroid excursion relative to event start.
-    // up_score: how far centroid excursed upward (smaller y) from first_c.
-    // down_score: how far it excursed downward (larger y) from first_c.
-    float up_score   = s.event_first_c - s.event_min_c;
-    float down_score = s.event_max_c   - s.event_first_c;
-
-    float winning = (up_score >= down_score) ? up_score : down_score;
-    if (winning < CV_EVENT_MIN_TRAJ) return;
-
-    // Timeout-aware direction. Quiet-exit events (fg fell below EXIT_THRESH)
-    // have walker fully out of frame → min/max excursion bracket the true
-    // traversal and up/down scores are reliable. Timeout events (event hit
-    // MAX_FRAMES while still elevated) captured both an approach and a
-    // departure within the window, so excursion measures the walker's
-    // *range in frame* rather than direction — an entry walker who paused
-    // near the top, then drifted back toward the middle before timeout
-    // gets (wrongly) called an entry by up-score even though net motion is
-    // mixed. For those, the net first→last centroid displacement is a
-    // better direction signal (it's where the walker ended up, not just
-    // where they peaked).
-    bool timed_out = (s.event_frame_count > CV_EVENT_MAX_FRAMES);
-    bool is_entry;
-    if (timed_out) {
-        is_entry = (s.event_last_c < s.event_first_c);
-    } else {
-        is_entry = (up_score >= down_score);
-    }
-    if (is_entry) {
-        s.entries++;
-        result.entries_delta++;
-    } else {
-        s.exits++;
-        result.exits_delta++;
-    }
-    s.last_fire_frame = s.frame_index;
-    result.fire_first_c  = s.event_first_c;
-    result.fire_min_c    = s.event_min_c;
-    result.fire_max_c    = s.event_max_c;
-    result.fire_last_c   = s.event_last_c;
-    result.fire_duration = s.event_frame_count;
-}
-
-CVResult cv_process(CVState& state, const uint8_t* frame, uint8_t /*line_pct*/) {
-    CVResult result = {0, 0, 0, -1, -1, -1.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0};
+CVResult cv_process(CVState& state, const uint8_t* frame) {
+    CVResult result = {0, 0};
     state.frame_index++;
 
     if (!state.bg_valid) {
@@ -156,147 +116,90 @@ CVResult cv_process(CVState& state, const uint8_t* frame, uint8_t /*line_pct*/)
         return result;
     }
 
-    static uint8_t fg[CV_PIXELS];
-    frame_diff(frame, state.background, fg, CV_PIXELS);
+    const uint8_t diff_thresh = state.tuning.diff_thresh;
+    const int     min_blob_px = state.tuning.min_blob_px;
+    const float   max_move    = state.tuning.max_move;
+    const int     max_missed  = state.tuning.max_missed;
 
-    // Running-average background blend: bg = (31*bg + frame)/32. Adapts to
-    // slow scene drift during idle periods. Frozen during an active event so
-    // the walker's signature is never absorbed — otherwise bg retains a
-    // "ghost" of the walker for ~30 frames after they leave, keeping fg_count
-    // elevated and preventing subsequent walkers from producing a clean
-    // trajectory.
-    if (!state.event_active) {
-        for (int i = 0; i < CV_PIXELS; i++) {
-            state.background[i] = (uint8_t)(((uint16_t)state.background[i] * 31 + frame[i]) >> 5);
-        }
-    }
+    static uint8_t fg[CV_PIXELS];  // static: avoids 9KB on task stack
+    frame_diff(frame, state.background, fg, CV_PIXELS, diff_thresh);
 
     int fg_count = 0;
-    int min_y = CV_H, max_y = -1;
-    long sum_y = 0;
-    for (int y = 0; y < CV_H; y++) {
-        const uint8_t* row = &fg[y * CV_W];
-        int row_count = 0;
-        for (int x = 0; x < CV_W; x++) row_count += row[x];
-        if (row_count > 0) {
-            if (y < min_y) min_y = y;
-            if (y > max_y) max_y = y;
-            sum_y += (long)row_count * y;
-            fg_count += row_count;
-        }
-    }
-    result.fg_count      = fg_count;
-    result.fg_min_y      = (fg_count > 0) ? min_y : -1;
-    result.fg_max_y      = (fg_count > 0) ? max_y : -1;
-    result.fg_centroid_y = (fg_count > 0) ? ((float)sum_y / fg_count) : -1.0f;
+    for (int i = 0; i < CV_PIXELS; i++) fg_count += fg[i];
 
-    // Hard self-heal: if more than half the frame is fg, bg is catastrophically
-    // wrong. Snap and skip the event machine this frame.
-    if (fg_count > CV_PIXELS / 2) {
-        memcpy(state.background, frame, CV_PIXELS);
-        state.last_motion_frame = state.frame_index;
-        if (state.event_active) event_reset(state);
-        return result;
-    }
-
-    // Diagnostic track management (no effect on counting).
-    bool motion = fg_count > CV_MIN_BLOB_PX;
-    if (motion) {
-        state.last_motion_frame = state.frame_index;
-        auto centroids = find_centroids(fg);
-        std::vector<bool> centroid_matched(centroids.size(), false);
-        for (auto& track : state.tracks) {
-            float best_dist = CV_MAX_MOVE * CV_MAX_MOVE;
-            int   best_idx  = -1;
-            for (int i = 0; i < (int)centroids.size(); i++) {
-                if (centroid_matched[i]) continue;
-                float dx = centroids[i].first  - track.x;
-                float dy = centroids[i].second - track.y;
-                float d2 = dx*dx + dy*dy;
-                if (d2 < best_dist) { best_dist = d2; best_idx = i; }
-            }
-            if (best_idx >= 0) {
-                centroid_matched[best_idx] = true;
-                track.x = centroids[best_idx].first;
-                track.y = centroids[best_idx].second;
-                track.missed = 0;
-            } else {
-                track.missed++;
-            }
+    bool motion = fg_count > min_blob_px;
+    if (!motion) {
+        if (state.frame_index - state.last_motion_frame > 10) {
+            memcpy(state.background, frame, CV_PIXELS);
         }
-        state.tracks.erase(
-            std::remove_if(state.tracks.begin(), state.tracks.end(),
-                [](const CVTrack& t){ return t.missed > CV_MAX_MISSED; }),
-            state.tracks.end());
-        for (int i = 0; i < (int)centroids.size(); i++) {
-            if (centroid_matched[i]) continue;
-            CVTrack t;
-            t.id      = state.next_id++;
-            t.x       = centroids[i].first;
-            t.y       = centroids[i].second;
-            t.spawn_y = t.y;
-            t.missed  = 0;
-            state.tracks.push_back(t);
-        }
-    } else {
         for (auto& t : state.tracks) t.missed++;
         state.tracks.erase(
             std::remove_if(state.tracks.begin(), state.tracks.end(),
-                [](const CVTrack& t){ return t.missed > CV_MAX_MISSED; }),
+                [max_missed](const CVTrack& t){ return t.missed > max_missed; }),
             state.tracks.end());
+        return result;
     }
 
-    // Event state machine. Refractory period after a fire blocks new events
-    // for CV_EVENT_REFRACTORY_FRAMES frames — absorbs lingering-walker motion
-    // that would otherwise re-trigger a second count.
-    bool in_refractory = state.last_fire_frame != 0 &&
-        (state.frame_index - state.last_fire_frame) < CV_EVENT_REFRACTORY_FRAMES;
+    state.last_motion_frame = state.frame_index;
 
-    if (!state.event_active) {
-        if (!in_refractory && fg_count >= CV_EVENT_ENTER_THRESH) {
-            state.event_active      = true;
-            state.event_start_frame = state.frame_index;
-            state.event_frame_count = 1;
-            state.event_peak_n      = fg_count;
-            state.event_first_c     = result.fg_centroid_y;
-            state.event_last_c      = result.fg_centroid_y;
-            state.event_min_c       = result.fg_centroid_y;
-            state.event_max_c       = result.fg_centroid_y;
-            state.event_min_y_seen  = min_y;
-            state.event_max_y_seen  = max_y;
-            state.event_quiet_count = 0;
+    auto centroids = find_centroids(fg, min_blob_px);
+
+    std::vector<bool> centroid_matched(centroids.size(), false);
+
+    for (auto& track : state.tracks) {
+        float best_dist = max_move * max_move;
+        int   best_idx  = -1;
+
+        for (int i = 0; i < (int)centroids.size(); i++) {
+            if (centroid_matched[i]) continue;
+            float dx = centroids[i].first  - track.x;
+            float dy = centroids[i].second - track.y;
+            float d2 = dx*dx + dy*dy;
+            if (d2 < best_dist) { best_dist = d2; best_idx = i; }
         }
-    } else {
-        state.event_frame_count++;
-        if (fg_count > state.event_peak_n) state.event_peak_n = fg_count;
-        if (fg_count > 0) {
-            state.event_last_c = result.fg_centroid_y;
-            if (result.fg_centroid_y < state.event_min_c) state.event_min_c = result.fg_centroid_y;
-            if (result.fg_centroid_y > state.event_max_c) state.event_max_c = result.fg_centroid_y;
-            if (min_y < state.event_min_y_seen) state.event_min_y_seen = min_y;
-            if (max_y > state.event_max_y_seen) state.event_max_y_seen = max_y;
-        }
-        if (fg_count < CV_EVENT_EXIT_THRESH) {
-            state.event_quiet_count++;
-            if (state.event_quiet_count >= CV_EVENT_QUIET_FRAMES) {
-                finalize_event(state, result);
-                event_reset(state);
-                memcpy(state.background, frame, CV_PIXELS);
-            }
+
+        if (best_idx >= 0) {
+            centroid_matched[best_idx] = true;
+            track.x = centroids[best_idx].first;
+            track.y = centroids[best_idx].second;
+            track.missed = 0;
         } else {
-            state.event_quiet_count = 0;
-            if (state.event_frame_count > CV_EVENT_MAX_FRAMES) {
-                // Timeout end: fg still elevated. Snap bg anyway — in practice
-                // a stuck-high event means bg is stale (walker has merged
-                // with stale bg, or AEC shifted). Leaving bg stale permanently
-                // poisons subsequent events. If a walker truly is mid-frame
-                // they'll get absorbed into bg, but that's a rare corner
-                // beaten by the common case of stale bg chaining events.
-                finalize_event(state, result);
-                event_reset(state);
-                memcpy(state.background, frame, CV_PIXELS);
+            track.missed++;
+        }
+    }
+
+    state.tracks.erase(
+        std::remove_if(state.tracks.begin(), state.tracks.end(),
+            [max_missed](const CVTrack& t){ return t.missed > max_missed; }),
+        state.tracks.end());
+
+    float line_y = (state.tuning.line_offset / 100.0f) * CV_H;
+    for (int i = 0; i < (int)centroids.size(); i++) {
+        if (centroid_matched[i]) continue;
+        CVTrack t;
+        t.id         = state.next_id++;
+        t.x          = centroids[i].first;
+        t.y          = centroids[i].second;
+        t.above_line = (t.y < line_y);
+        t.missed     = 0;
+        state.tracks.push_back(t);
+    }
+    // Line crossing check
+    for (auto& track : state.tracks) {
+        if (track.missed > 0) continue; // only check tracks matched this frame
+        bool now_above = (track.y < line_y);
+        if (now_above != track.above_line) {
+            if (!now_above) {
+                // was above, now below → entry
+                state.entries++;
+                result.entries_delta++;
+            } else {
+                // was below, now above → exit
+                state.exits++;
+                result.exits_delta++;
             }
         }
+        track.above_line = now_above;
     }
 
     return result;

firmware/lib/cv/cv.h

@@ -7,71 +7,22 @@ static const int CV_W = 96;
 static const int CV_H = 96;
 static const int CV_PIXELS = CV_W * CV_H;
 
-static const uint8_t CV_DIFF_THRESH = 30;
-static const int CV_MIN_BLOB_PX = 64;
-static const float CV_MAX_MOVE = 15.0f;
-static const int CV_MAX_MISSED = 10;
-
-// Event-based walker detector. Per-frame zone-flip approaches were direction-
-// blind at realistic mounts: a walker traversing top-to-bottom and a walker
-// traversing bottom-to-top produced identical zone-dominance sequences
-// (geometric artifact of asymmetric zones + body spanning the line). The
-// event approach buffers a whole walker event, then decides direction from
-// the centroid trajectory: sign(first_centroid_y - peak_centroid_y) > 0 means
-// the centroid moved upward through the frame during the event.
-//
-// Per-mount convention: UP through frame == ENTRY into store. Flip the camera
-// mount or invert the mapping in cv_process if the physical install differs.
-
-// fg_count thresholds that gate event start/end. Tuned against a real
-// 8-walk isolated test (see .agent/walk_isolated_8walks.log). Lower than
-// initial guesses because the 7' overhead mount produces smaller centroid
-// excursions than we originally modelled.
-static const int CV_EVENT_ENTER_THRESH = 250;
-static const int CV_EVENT_EXIT_THRESH  = 150;
-
-// Number of consecutive sub-EXIT frames required to end an event.
-static const int CV_EVENT_QUIET_FRAMES = 3;
-
-// Min/max event duration in frames. Below min = too brief to be a walker
-// (noise burst). Above max = stationary object or stuck detection.
-static const int CV_EVENT_MIN_FRAMES = 5;
-// MAX bounds the event duration. Too low (15) cut events off while walker
-// was still physically in frame — every fire hit dur=MAX+1 and bg snapped
-// with a walker-ghost baked in, corrupting the next walk. Too high (40)
-// merged multiple walkers. 25 frames (5s) lets a single walker reach the
-// quiet-exit path (fg drops below EXIT_THRESH) before timeout, so bg snaps
-// on a clean empty frame.
-static const int CV_EVENT_MAX_FRAMES = 25;
-
-// Required vertical extent: during the event, fg must have reached near the
-// top of the frame (min_y <= TOP) AND near the bottom (max_y >= BOT). At a
-// 7' overhead mount real walkers span fg y≈0..70, not 0..95 — the original
-// 10/85 gates rejected most real walks. Relaxed to catch them while still
-// filtering small local motion that doesn't span the doorway.
-static const int CV_EVENT_EXTENT_TOP = 25;
-static const int CV_EVENT_EXTENT_BOT = 50;
-
-// Minimum centroid excursion (max of up_score/down_score) for a valid
-// trajectory. At overhead mount walker centroid traverses ~15-40 pixels;
-// 15 was too aggressive and dropped clean walks. 5 still filters wobble.
-static const float CV_EVENT_MIN_TRAJ = 5.0f;
-
-// Refractory period after a fire. Shorter than originally chosen — at 5 fps
-// a second walker can arrive within 2s of the first, especially at busy
-// doorways. 10 frames = 2s of back-pressure, tuned to match the gap between
-// consecutive isolated walks in the test log.
-static const uint32_t CV_EVENT_REFRACTORY_FRAMES = 10;
-
-// Diagnostic only: tracks are kept for spawn logging. Counting does NOT
-// depend on tracks.
 struct CVTrack {
     int   id;
     float x, y;
-    float spawn_y;
+    bool  above_line;
     int   missed;
 };
 
+struct CVTuning {
+    uint8_t  diff_thresh;   // per-pixel motion threshold
+    int      min_blob_px;   // min foreground pixels for a blob
+    float    max_move;      // max inter-frame track jump (px)
+    int      max_missed;    // frames before drop
+    uint8_t  line_offset;   // 0-100, percent of frame height for virtual line
+    uint32_t cfg_version;   // monotonic; server increments on push
+};
+
 struct CVState {
     uint8_t  background[CV_PIXELS];
     bool     bg_valid;
@@ -81,38 +32,18 @@ struct CVState {
     std::vector<CVTrack> tracks;
     int entries;
     int exits;
-
-    // Event state machine.
-    bool     event_active;
-    uint32_t event_start_frame;
-    int      event_frame_count;
-    int      event_peak_n;
-    float    event_first_c;
-    float    event_last_c;
-    float    event_min_c;        // min centroid_y observed during event
-    float    event_max_c;        // max centroid_y observed during event
-    int      event_min_y_seen;
-    int      event_max_y_seen;
-    int      event_quiet_count;
-    uint32_t last_fire_frame;    // 0 = never; frame of last counted fire
+    CVTuning tuning;
 };
 
 struct CVResult {
     int entries_delta;
     int exits_delta;
-    // Per-frame foreground diagnostics (populated every call).
-    int   fg_count;
-    int   fg_min_y;
-    int   fg_max_y;
-    float fg_centroid_y;
-    // Populated only on a fire frame; zeroed otherwise.
-    float fire_first_c;
-    float fire_min_c;
-    float fire_max_c;
-    float fire_last_c;
-    int   fire_duration;
 };
 
 void cv_init(CVState& state);
-CVResult cv_process(CVState& state, const uint8_t* frame, uint8_t line_pct);
+CVResult cv_process(CVState& state, const uint8_t* frame);
 void cv_reset_counts(CVState& state);
+
+// Pure validator: returns true iff all tunable fields are in range and
+// cfg_version is non-zero. No Arduino deps — safe for native tests.
+bool cv_tuning_validate(const CVTuning& t);

firmware/platformio.ini

@@ -7,7 +7,6 @@ platform = espressif32@6.6.0
 board = m5stack-timer-cam
 framework = arduino
 board_build.partitions = partitions_4mb_ota.csv
-build_src_filter = +<*> -<main_capture.cpp>
 build_flags =
     -DBOARD_HAS_PSRAM
     -mfix-esp32-psram-cache-issue
@@ -24,25 +23,6 @@ lib_deps =
     h2zero/NimBLE-Arduino@^1.4.2
     espressif/esp32-camera
 
-; Frame-capture build. Strips WiFi/BLE/CV/reporter; streams raw 96x96 frames
-; over serial at 921600 baud for offline algorithm iteration.
-[env:timercam-capture]
-platform = espressif32@6.6.0
-board = m5stack-timer-cam
-framework = arduino
-board_build.partitions = partitions_4mb_ota.csv
-build_flags =
-    -DBOARD_HAS_PSRAM
-    -mfix-esp32-psram-cache-issue
-    -DCORE_DEBUG_LEVEL=0
-    -DCONFIG_SPIRAM_USE_MALLOC=1
-build_src_filter = -<*> +<main_capture.cpp> +<camera.cpp>
-monitor_speed = 460800
-upload_speed = 115200
-upload_flags = --no-stub
-lib_deps =
-    espressif/esp32-camera
-
 [env:native]
 platform = native
 test_framework = unity

firmware/src/config.cpp

@@ -13,7 +13,6 @@ bool config_load(DeviceConfig& cfg) {
     cfg.hmac_secret = prefs.getString("hmac_secret", "");
     cfg.wifi_ssid   = prefs.getString("wifi_ssid", "");
     cfg.wifi_pass   = prefs.getString("wifi_pass", "");
-    cfg.line_offset = (uint8_t)prefs.getUInt("line_offset", 50);
 
     prefs.end();
 
@@ -46,3 +45,55 @@ void config_clear_wifi() {
     prefs.remove("wifi_pass");
     prefs.end();
 }
+
+bool config_load_tuning(CVTuning& tuning) {
+    Preferences prefs;
+    prefs.begin(NS, true); // read-only
+
+    uint32_t ver = prefs.getUInt("cv_ver", UINT32_MAX);
+    if (ver == UINT32_MAX) {
+        prefs.end();
+        return false;
+    }
+
+    // All six keys must be present; use sentinels to detect missing.
+    uint32_t diff = prefs.getUInt("cv_diff", UINT32_MAX);
+    uint32_t blob = prefs.getUInt("cv_blob", UINT32_MAX);
+    uint32_t miss = prefs.getUInt("cv_miss", UINT32_MAX);
+    uint32_t line = prefs.getUInt("cv_line", UINT32_MAX);
+    bool has_move = prefs.isKey("cv_move");
+    float    move = prefs.getFloat("cv_move", 0.0f);
+
+    prefs.end();
+
+    if (diff == UINT32_MAX || blob == UINT32_MAX ||
+        miss == UINT32_MAX || line == UINT32_MAX || !has_move) {
+        return false;
+    }
+
+    tuning.diff_thresh = (uint8_t)diff;
+    tuning.min_blob_px = (int)blob;
+    tuning.max_move    = move;
+    tuning.max_missed  = (int)miss;
+    tuning.line_offset = (uint8_t)line;
+    tuning.cfg_version = ver;
+    return true;
+}
+
+bool config_save_tuning(const CVTuning& tuning) {
+    Preferences prefs;
+    prefs.begin(NS, false);
+    size_t r1 = prefs.putUInt("cv_diff", (uint32_t)tuning.diff_thresh);
+    size_t r2 = prefs.putUInt("cv_blob", (uint32_t)tuning.min_blob_px);
+    size_t r3 = prefs.putFloat("cv_move", tuning.max_move);
+    size_t r4 = prefs.putUInt("cv_miss", (uint32_t)tuning.max_missed);
+    size_t r5 = prefs.putUInt("cv_line", (uint32_t)tuning.line_offset);
+    if (!(r1 > 0 && r2 > 0 && r3 > 0 && r4 > 0 && r5 > 0)) {
+        prefs.end();
+        return false;
+    }
+    // cv_ver is the atomic commit marker: only written after all tunables succeed.
+    size_t r6 = prefs.putUInt("cv_ver",  tuning.cfg_version);
+    prefs.end();
+    return r6 > 0;
+}

firmware/src/config.h

@@ -1,6 +1,7 @@
 // firmware/src/config.h
 #pragma once
 #include <Arduino.h>
+#include "cv.h"
 
 struct DeviceConfig {
     String device_id;      // e.g. "dc-0042"
@@ -8,7 +9,6 @@ struct DeviceConfig {
     String hmac_secret;    // 32-byte hex string
     String wifi_ssid;
     String wifi_pass;
-    uint8_t line_offset;   // 0-100, percent of frame height for virtual line
 };
 
 // Load all config from NVS. Returns false if device_id/location_id/hmac_secret missing.
@@ -22,3 +22,10 @@ bool config_has_wifi();
 
 // Erase WiFi credentials only (factory reset — preserves device_id etc).
 void config_clear_wifi();
+
+// Load CV tuning from NVS. Returns true only if all keys present (cfg_version sentinel).
+// If any key missing, tuning is NOT modified (caller keeps its defaults).
+bool config_load_tuning(CVTuning& tuning);
+
+// Save CV tuning to NVS atomically. Returns true if all writes succeeded.
+bool config_save_tuning(const CVTuning& tuning);

firmware/src/cv_apply.h

@@ -0,0 +1,13 @@
+// firmware/src/cv_apply.h
+#pragma once
+#include "cv.h"
+
+// Take s_cv_mutex, copy the tuning into g_cv.tuning, release.
+// Non-blocking semantics: if mutex is unavailable after 500 ms, logs and
+// drops (caller may retry next cycle).
+void cv_apply_tuning(const CVTuning& incoming);
+
+// Take s_cv_mutex, copy g_cv.tuning into out. For reporter use when
+// comparing candidate configs. If the mutex is unavailable, logs and
+// leaves `out` unchanged.
+void cv_get_tuning(CVTuning& out);

firmware/src/main.cpp

@@ -6,6 +6,7 @@
 #include "provisioning.h"
 #include "camera.h"
 #include "cv.h"
+#include "cv_apply.h"
 #include "ble_scanner.h"
 #include "reporter.h"
 
@@ -24,22 +25,31 @@ static DeviceConfig     g_cfg;
 static CVState          g_cv;
 static SemaphoreHandle_t s_cv_mutex = nullptr;
 
-static void led_set(bool on) { digitalWrite(LED_PIN, on ? HIGH : LOW); }
-
-// Non-blocking-ish detection blink. Saves and restores the current LED state
-// so it doesn't clobber upload/no-wifi indicators. Total duration: ~60ms per
-// pulse + 80ms gap between pulses.
-static void led_blink_pattern(int pulses) {
-    bool prev = digitalRead(LED_PIN);
-    for (int i = 0; i < pulses; i++) {
-        led_set(true);
-        vTaskDelay(pdMS_TO_TICKS(60));
-        led_set(false);
-        if (i < pulses - 1) vTaskDelay(pdMS_TO_TICKS(80));
+// cv_apply.h definitions — live here because they need g_cv + s_cv_mutex.
+void cv_apply_tuning(const CVTuning& incoming) {
+    if (!s_cv_mutex) return; // pre-init guard
+    if (xSemaphoreTake(s_cv_mutex, pdMS_TO_TICKS(500)) == pdTRUE) {
+        g_cv.tuning = incoming;
+        xSemaphoreGive(s_cv_mutex);
+    } else {
+        Serial.println("[CFG] apply skipped (mutex busy)");
     }
-    led_set(prev);
 }
 
+void cv_get_tuning(CVTuning& out) {
+    out = CVTuning{};
+    if (!s_cv_mutex) return;
+    if (xSemaphoreTake(s_cv_mutex, pdMS_TO_TICKS(500)) == pdTRUE) {
+        out = g_cv.tuning;
+        xSemaphoreGive(s_cv_mutex);
+    } else {
+        Serial.println("[CFG] get_tuning skipped (mutex busy)");
+    }
+}
+
+// LED: simple on/off — blink patterns can be added later
+static void led_set(bool on) { digitalWrite(LED_PIN, on ? HIGH : LOW); }
+
 static void check_factory_reset() {
     if (digitalRead(BUTTON_PIN) != LOW) return;
     uint32_t held = millis();
@@ -55,30 +65,13 @@ static void check_factory_reset() {
 // Camera + CV task — runs on core 1 at 5 fps
 static void task_camera(void*) {
     static uint8_t frame[CV_PIXELS];  // static: avoids 9KB on task stack
-    int last_logged_track_id = 0;     // diagnostic: log each new track once
     while (true) {
         if (camera_capture_96(frame)) {
             if (xSemaphoreTake(s_cv_mutex, pdMS_TO_TICKS(100)) == pdTRUE) {
-                CVResult r = cv_process(g_cv, frame, g_cfg.line_offset);
-                for (const auto& t : g_cv.tracks) {
-                    if (t.id > last_logged_track_id) {
-                        last_logged_track_id = t.id;
-                        Serial.printf("[CV] spawn id=%d y=%.1f\n", t.id, t.spawn_y);
-                    }
-                }
-                if (r.fg_count > 0) {
-                    Serial.printf("[F] n=%d y=%d..%d c=%.1f\n",
-                        r.fg_count, r.fg_min_y, r.fg_max_y, r.fg_centroid_y);
-                }
-                if (r.entries_delta) Serial.printf("[CV] entry +%d (total %d) first=%.1f min=%.1f max=%.1f last=%.1f dur=%d\n",
-                    r.entries_delta, g_cv.entries,
-                    r.fire_first_c, r.fire_min_c, r.fire_max_c, r.fire_last_c, r.fire_duration);
-                if (r.exits_delta)   Serial.printf("[CV] exit  +%d (total %d) first=%.1f min=%.1f max=%.1f last=%.1f dur=%d\n",
-                    r.exits_delta,  g_cv.exits,
-                    r.fire_first_c, r.fire_min_c, r.fire_max_c, r.fire_last_c, r.fire_duration);
+                CVResult r = cv_process(g_cv, frame);
+                if (r.entries_delta) Serial.printf("[CV] entry +%d (total %d)\n", r.entries_delta, g_cv.entries);
+                if (r.exits_delta)   Serial.printf("[CV] exit  +%d (total %d)\n", r.exits_delta,  g_cv.exits);
                 xSemaphoreGive(s_cv_mutex);
-                if (r.entries_delta) led_blink_pattern(1);
-                if (r.exits_delta)   led_blink_pattern(2);
             }
         }
         vTaskDelay(pdMS_TO_TICKS(CAM_INTERVAL_MS));
@@ -170,6 +163,11 @@ void setup() {
     configTime(0, 0, "pool.ntp.org", "time.nist.gov");
 
     cv_init(g_cv);
+    if (config_load_tuning(g_cv.tuning)) {
+        Serial.printf("[CFG] tuning loaded from NVS, cfg_version=%u\n", g_cv.tuning.cfg_version);
+    } else {
+        Serial.println("[CFG] no persisted tuning, using defaults");
+    }
 
     if (!camera_init()) {
         Serial.println("FATAL: camera init failed");

firmware/src/main_capture.cpp

@@ -1,64 +0,0 @@
-// firmware/src/main_capture.cpp
-//
-// Frame-dump firmware. Replaces main.cpp when building env:timercam-capture.
-// Streams raw 96x96 grayscale frames at 5 fps over serial (921600 baud) for
-// offline algorithm iteration.
-//
-// Wire format per frame (little-endian):
-//   magic    uint32  0xDC0FC0DE
-//   frame_ix uint32  monotonic counter
-//   millis   uint32  ms since boot
-//   pixels   byte[9216]  raw grayscale 96x96, row-major
-//
-// No WiFi, no BLE, no CV. Just camera → serial.
-
-#include <Arduino.h>
-#include "camera.h"
-#include "cv.h"  // for CV_PIXELS
-
-#define LED_PIN 2
-#define CAM_FPS 5
-#define CAM_INTERVAL_MS (1000 / CAM_FPS)
-
-// Magic chosen from bytes that commonly survive; 'FRM1' ascii.
-// Avoid high bytes 0xA0-AF / 0xD0-DF — observed missing from the CH9102 stream.
-static const uint32_t FRAME_MAGIC = 0x314D5246; // 'FRM1' little-endian on wire
-
-void setup() {
-    Serial.begin(460800);
-    pinMode(LED_PIN, OUTPUT);
-    digitalWrite(LED_PIN, HIGH);
-
-    delay(500);
-    Serial.println("# capture-mode: 460800 baud, 96x96 gray @ 5fps");
-    Serial.flush();
-
-    if (!camera_init()) {
-        Serial.println("# FATAL: camera init failed");
-        while (true) {
-            digitalWrite(LED_PIN, !digitalRead(LED_PIN));
-            delay(200);
-        }
-    }
-
-    digitalWrite(LED_PIN, LOW);
-}
-
-void loop() {
-    static uint8_t frame[CV_PIXELS];
-    static uint32_t frame_ix = 0;
-    uint32_t t0 = millis();
-
-    if (camera_capture_96(frame)) {
-        uint32_t ms = millis();
-        Serial.write((uint8_t*)&FRAME_MAGIC, 4);
-        Serial.write((uint8_t*)&frame_ix,    4);
-        Serial.write((uint8_t*)&ms,          4);
-        Serial.write(frame, CV_PIXELS);
-        frame_ix++;
-        digitalWrite(LED_PIN, frame_ix & 1);
-    }
-
-    uint32_t elapsed = millis() - t0;
-    if (elapsed < CAM_INTERVAL_MS) delay(CAM_INTERVAL_MS - elapsed);
-}

firmware/src/reporter.cpp

@@ -1,6 +1,8 @@
 // firmware/src/reporter.cpp
 #include "reporter.h"
 #include "hmac.h"
+#include "cv_apply.h"
+#include "config.h"
 #include <HTTPClient.h>
 #include <ArduinoJson.h>
 #include <WiFi.h>
@@ -21,12 +23,17 @@ static uint32_t now_ts() {
     return (uint32_t)time(nullptr);
 }
 
-static bool post_json(const DeviceConfig& cfg, const char* path, const String& body) {
+// Returns HTTP status code on success, negative HTTPClient error code on
+// transport failure. Returns -1 if pre-flight checks (NTP, HMAC) fail.
+// If response_body is non-null and the request succeeded (2xx), captures
+// the response (truncated to 2048 chars).
+static int post_json(const DeviceConfig& cfg, const char* path,
+                     const String& body, String* response_body = nullptr) {
     uint32_t ts  = now_ts();
     // Reject if NTP hasn't synced yet (timestamp would be near epoch 0)
-    if (ts < 1700000000UL) return false; // pre-2023 → clock not valid
+    if (ts < 1700000000UL) return -1; // pre-2023 → clock not valid
     String   sig = hmac_sign(cfg.hmac_secret, "POST", path, ts, body);
-    if (sig.isEmpty()) return false; // HMAC failed
+    if (sig.isEmpty()) return -1; // HMAC failed
 
     HTTPClient http;
     String url = String(REPORTER_API_HOST) + path;
@@ -37,9 +44,14 @@ static bool post_json(const DeviceConfig& cfg, const char* path, const String& b
     http.addHeader("X-Signature",  sig);
 
     int code = http.POST(body);
+    if (response_body && code >= 200 && code < 300) {
+        String r = http.getString();
+        if (r.length() > 2048) r.remove(2048);
+        *response_body = r;
+    }
     http.end();
     Serial.printf("[HTTP] POST %s → %d\n", url.c_str(), code);
-    return (code == 200);
+    return code;
 }
 
 static String build_camera_batch(const DeviceConfig& cfg,
@@ -111,7 +123,7 @@ void reporter_submit_camera(const DeviceConfig& cfg, const CameraHourlyRecord& r
     }
 
     String body = build_camera_batch(cfg, batch);
-    if (!post_json(cfg, "/api/v1/camera/events/batch", body)) {
+    if (post_json(cfg, "/api/v1/camera/events/batch", body) != 200) {
         xSemaphoreTake(s_buf_mutex, portMAX_DELAY);
         s_cam_buf = batch; // re-buffer the whole capped batch
         xSemaphoreGive(s_buf_mutex);
@@ -140,7 +152,7 @@ void reporter_submit_ble(const DeviceConfig& cfg, const BLEHourlyRecord& rec) {
     }
 
     String body = build_ble_batch(cfg, batch);
-    if (!post_json(cfg, "/api/v1/events/batch", body)) {
+    if (post_json(cfg, "/api/v1/events/batch", body) != 200) {
         xSemaphoreTake(s_buf_mutex, portMAX_DELAY);
         s_ble_buf = batch; // re-buffer the whole capped batch
         xSemaphoreGive(s_buf_mutex);
@@ -156,7 +168,80 @@ void reporter_heartbeat(const DeviceConfig& cfg, uint32_t uptime_s, int wifi_rss
     doc["pending_records"]   = (int)(s_cam_buf.size() + s_ble_buf.size());
     doc["uptime_seconds"]    = uptime_s;
     String body; serializeJson(doc, body);
-    post_json(cfg, "/api/v1/heartbeat", body);
+
+    String resp;
+    int code = post_json(cfg, "/api/v1/heartbeat", body, &resp);
+    if (code != 200 || resp.isEmpty()) return;
+
+    JsonDocument rdoc;
+    DeserializationError err = deserializeJson(rdoc, resp);
+    if (err) {
+        Serial.println("[CFG] bad JSON in heartbeat response");
+        return;
+    }
+    JsonVariant cfgv = rdoc["config"];
+    if (!cfgv.is<JsonObject>()) return; // no config pushed → silent no-op
+    JsonObject obj = cfgv.as<JsonObject>();
+
+    if (!obj["cfg_version"].is<uint32_t>() && !obj["cfg_version"].is<int>()) {
+        Serial.println("[CFG] missing cfg_version, skip");
+        return;
+    }
+    uint32_t new_ver = obj["cfg_version"].as<uint32_t>();
+
+    CVTuning current;
+    cv_get_tuning(current);
+    if (new_ver <= current.cfg_version) {
+        Serial.printf("[CFG] stale version %u (have %u), skip\n",
+                      (unsigned)new_ver, (unsigned)current.cfg_version);
+        return;
+    }
+
+    CVTuning candidate = current;
+    candidate.cfg_version = new_ver;
+
+    // Present-but-wrong-type fields reject the whole update. Absent fields
+    // (isNull == true) fall back to the current value. This prevents
+    // cfg_version bumping while silently dropping malformed fields.
+    bool bad_type = false;
+    if (!obj["diff_thresh"].isNull()) {
+        if (!obj["diff_thresh"].is<int>()) bad_type = true;
+        else candidate.diff_thresh = (uint8_t)obj["diff_thresh"].as<int>();
+    }
+    if (!obj["min_blob_px"].isNull()) {
+        if (!obj["min_blob_px"].is<int>()) bad_type = true;
+        else candidate.min_blob_px = obj["min_blob_px"].as<int>();
+    }
+    if (!obj["max_move"].isNull()) {
+        // max_move is float — accept int literal too (JSON 12 vs 12.0)
+        if (!(obj["max_move"].is<float>() || obj["max_move"].is<double>()
+              || obj["max_move"].is<int>())) bad_type = true;
+        else candidate.max_move = obj["max_move"].as<float>();
+    }
+    if (!obj["max_missed"].isNull()) {
+        if (!obj["max_missed"].is<int>()) bad_type = true;
+        else candidate.max_missed = obj["max_missed"].as<int>();
+    }
+    if (!obj["line_offset"].isNull()) {
+        if (!obj["line_offset"].is<int>()) bad_type = true;
+        else candidate.line_offset = (uint8_t)obj["line_offset"].as<int>();
+    }
+    if (bad_type) {
+        Serial.printf("[CFG] rejected malformed config v=%u\n", (unsigned)new_ver);
+        return;
+    }
+
+    if (!cv_tuning_validate(candidate)) {
+        Serial.printf("[CFG] rejected invalid config v=%u\n", (unsigned)new_ver);
+        return;
+    }
+
+    if (!config_save_tuning(candidate)) {
+        Serial.printf("[CFG] rejected v=%u: NVS save failed\n", (unsigned)new_ver);
+        return;
+    }
+    cv_apply_tuning(candidate);
+    Serial.printf("[CFG] applied v=%u\n", (unsigned)new_ver);
 }
 
 void reporter_flush(const DeviceConfig& cfg) {
@@ -167,7 +252,7 @@ void reporter_flush(const DeviceConfig& cfg) {
 
     if (!cam_snap.empty()) {
         String body = build_camera_batch(cfg, cam_snap);
-        if (post_json(cfg, "/api/v1/camera/events/batch", body)) {
+        if (post_json(cfg, "/api/v1/camera/events/batch", body) == 200) {
             xSemaphoreTake(s_buf_mutex, portMAX_DELAY);
             s_cam_buf.clear();
             xSemaphoreGive(s_buf_mutex);
@@ -175,7 +260,7 @@ void reporter_flush(const DeviceConfig& cfg) {
     }
     if (!ble_snap.empty()) {
         String body = build_ble_batch(cfg, ble_snap);
-        if (post_json(cfg, "/api/v1/events/batch", body)) {
+        if (post_json(cfg, "/api/v1/events/batch", body) == 200) {
             xSemaphoreTake(s_buf_mutex, portMAX_DELAY);
             s_ble_buf.clear();
             xSemaphoreGive(s_buf_mutex);

firmware/test/test_cv/test_cv.cpp

@@ -7,290 +7,261 @@ static void fill_frame(uint8_t* f, uint8_t val) {
     memset(f, val, CV_PIXELS);
 }
 
-// Draw a rectangular walker-blob spanning rows [y0, y1], columns [cx-hw, cx+hw].
-// Pixel value 200 over background 100 -> frame_diff threshold (30) is cleared.
-static void draw_walker(uint8_t* f, int y0, int y1, int cx, int hw) {
-    fill_frame(f, 100);
-    for (int y = y0; y <= y1; y++) {
-        if (y < 0 || y >= CV_H) continue;
-        for (int x = cx - hw; x <= cx + hw; x++) {
-            if (x < 0 || x >= CV_W) continue;
-            f[y * CV_W + x] = 200;
-        }
-    }
-}
-
-static void prime_bg(CVState& state) {
-    uint8_t bg[CV_PIXELS];
-    fill_frame(bg, 100);
-    cv_process(state, bg, 50);
-}
-
-// Let the event state machine see QUIET_FRAMES+1 empty frames so any active
-// event finalizes before the next test assertion.
-static void quiesce(CVState& state) {
-    uint8_t bg[CV_PIXELS]; fill_frame(bg, 100);
-    for (int i = 0; i < CV_EVENT_QUIET_FRAMES + 1; i++) cv_process(state, bg, 50);
-}
-
 void setUp(void) {}
 void tearDown(void) {}
 
-void test_no_change_no_event() {
-    CVState state; cv_init(state);
-    uint8_t frame[CV_PIXELS]; fill_frame(frame, 128);
-    CVResult r1 = cv_process(state, frame, 50);
+void test_frame_diff_no_change_gives_no_fg() {
+    CVState state;
+    cv_init(state);
+
+    uint8_t frame[CV_PIXELS];
+    fill_frame(frame, 128);
+
+    CVResult r1 = cv_process(state, frame);
     TEST_ASSERT_EQUAL_INT(0, r1.entries_delta);
-    CVResult r2 = cv_process(state, frame, 50);
+
+    CVResult r2 = cv_process(state, frame);
     TEST_ASSERT_EQUAL_INT(0, r2.entries_delta);
     TEST_ASSERT_EQUAL_INT(0, r2.exits_delta);
 }
 
+void test_frame_diff_large_change_detected_no_crash() {
+    CVState state;
+    cv_init(state);
+
+    uint8_t bg[CV_PIXELS], fg_frame[CV_PIXELS];
+    fill_frame(bg, 100);
+    fill_frame(fg_frame, 200);
+
+    cv_process(state, bg);
+    CVResult r = cv_process(state, fg_frame);
+
+    // Tracking not yet implemented — just verify no crash and result is zero
+    TEST_ASSERT_EQUAL_INT(0, r.entries_delta);
+    TEST_ASSERT_EQUAL_INT(0, r.exits_delta);
+}
+
 void test_cv_init_clears_state() {
     CVState state;
-    state.entries = 99; state.exits = 88; state.event_active = true;
+    state.entries = 99; state.exits = 88;
     cv_init(state);
     TEST_ASSERT_EQUAL_INT(0, state.entries);
     TEST_ASSERT_EQUAL_INT(0, state.exits);
     TEST_ASSERT_FALSE(state.bg_valid);
-    TEST_ASSERT_FALSE(state.event_active);
 }
 
 void test_cv_reset_counts() {
-    CVState state; cv_init(state);
-    state.entries = 5; state.exits = 3;
+    CVState state;
+    cv_init(state);
+    state.entries = 5;
+    state.exits   = 3;
     cv_reset_counts(state);
     TEST_ASSERT_EQUAL_INT(0, state.entries);
     TEST_ASSERT_EQUAL_INT(0, state.exits);
 }
 
-void test_walker_up_through_frame_is_entry() {
-    // Simulate a walker traversing from bottom to top of frame.
-    // Per-frame fg_count and centroid (11-wide column, height H -> n=11*H):
-    //   t0 y=60..95 n=396 c=77   <- event starts (n >= ENTER=300)
-    //   t1 y=30..95 n=726 c=62
-    //   t2 y=0..95  n=1056 c=47
-    //   t3 y=0..60  n=671 c=30
-    //   t4 y=0..25  n=286 c=12   (below EXIT=200, quiet=1)
-    //   t5 y=0..10  n=121 c=5    (below EXIT, quiet=2)
-    //   t6 empty                  quiet=3 -> finalize
-    CVState state; cv_init(state);
-    prime_bg(state);
+void test_tracking_spawns_track_for_new_blob() {
+    CVState state;
+    cv_init(state);
 
-    int rows[][2] = {{60,95},{30,95},{0,95},{0,60},{0,25},{0,10}};
-    for (int i = 0; i < 6; i++) {
-        uint8_t f[CV_PIXELS]; draw_walker(f, rows[i][0], rows[i][1], 48, 5);
-        cv_process(state, f, 50);
+    uint8_t bg[CV_PIXELS];
+    fill_frame(bg, 100);
+    cv_process(state, bg); // init background
+
+    // Frame with a bright 30x30 blob in top-left quadrant
+    uint8_t blob_frame[CV_PIXELS];
+    fill_frame(blob_frame, 100);
+    for (int y = 5; y < 35; y++)
+        for (int x = 5; x < 35; x++)
+            blob_frame[y * CV_W + x] = 200;
+
+    cv_process(state, blob_frame);
+
+    TEST_ASSERT_EQUAL_INT(1, (int)state.tracks.size());
+    TEST_ASSERT_FLOAT_WITHIN(5.0f, 20.0f, state.tracks[0].x);
+    TEST_ASSERT_FLOAT_WITHIN(5.0f, 20.0f, state.tracks[0].y);
+}
+
+static void make_blob_frame(uint8_t* f, int cx, int cy) {
+    fill_frame(f, 100);
+    for (int y = cy - 12; y <= cy + 12; y++)
+        for (int x = cx - 12; x <= cx + 12; x++)
+            if (y >= 0 && y < CV_H && x >= 0 && x < CV_W)
+                f[y * CV_W + x] = 200;
+}
+
+void test_blob_crossing_line_top_to_bottom_is_entry() {
+    CVState state;
+    cv_init(state);
+
+    // Line at 50% = y=48; step ≤14px per frame to stay within max_move (default 15)
+    uint8_t bg[CV_PIXELS];
+    fill_frame(bg, 100);
+    cv_process(state, bg); // init background
+
+    // Walk blob from y=20 toward line; crossing occurs at y=48 (above→below)
+    // Stop at crossing frame and assert its result
+    int setup[] = {20, 34};
+    for (int i = 0; i < 2; i++) {
+        uint8_t f[CV_PIXELS]; make_blob_frame(f, 48, setup[i]);
+        cv_process(state, f);
     }
-    quiesce(state);
+    uint8_t fcross[CV_PIXELS]; make_blob_frame(fcross, 48, 48);
+    CVResult r = cv_process(state, fcross);
 
+    TEST_ASSERT_EQUAL_INT(1, r.entries_delta);
+    TEST_ASSERT_EQUAL_INT(0, r.exits_delta);
     TEST_ASSERT_EQUAL_INT(1, state.entries);
-    TEST_ASSERT_EQUAL_INT(0, state.exits);
 }
 
-void test_walker_down_through_frame_is_exit() {
-    CVState state; cv_init(state);
-    prime_bg(state);
+void test_blob_crossing_line_bottom_to_top_is_exit() {
+    CVState state;
+    cv_init(state);
 
-    int rows[][2] = {{0,35},{0,65},{0,95},{35,95},{70,95},{85,95}};
-    for (int i = 0; i < 6; i++) {
-        uint8_t f[CV_PIXELS]; draw_walker(f, rows[i][0], rows[i][1], 48, 5);
-        cv_process(state, f, 50);
-    }
-    quiesce(state);
-
-    TEST_ASSERT_EQUAL_INT(0, state.entries);
-    TEST_ASSERT_EQUAL_INT(1, state.exits);
-}
-
-void test_approach_retreat_without_full_extent_does_not_fire() {
-    // Walker approaches from bottom, reaches y=30, retreats, never reaches top.
-    // Extent gate requires min_y_seen <= 10; this event tops out at y=30 so
-    // extent never clears and no fire occurs regardless of trajectory score.
-    CVState state; cv_init(state);
-    prime_bg(state);
-
-    int rows[][2] = {{60,95},{40,95},{30,95},{40,95},{60,95},{80,95}};
-    for (int i = 0; i < 6; i++) {
-        uint8_t f[CV_PIXELS]; draw_walker(f, rows[i][0], rows[i][1], 48, 5);
-        cv_process(state, f, 50);
-    }
-    quiesce(state);
-
-    TEST_ASSERT_EQUAL_INT(0, state.entries);
-    TEST_ASSERT_EQUAL_INT(0, state.exits);
-}
-
-void test_brief_burst_below_min_duration_does_not_fire() {
-    // One frame of large fg, then gone. Event starts, immediately quiesces,
-    // duration ends up below CV_EVENT_MIN_FRAMES.
-    CVState state; cv_init(state);
-    prime_bg(state);
-
-    uint8_t f[CV_PIXELS]; draw_walker(f, 0, 95, 48, 5);
-    cv_process(state, f, 50);
-    quiesce(state);
-
-    TEST_ASSERT_EQUAL_INT(0, state.entries);
-    TEST_ASSERT_EQUAL_INT(0, state.exits);
-}
-
-void test_stationary_large_blob_does_not_fire() {
-    // Static large blob in frame for many frames, then removed. Centroid
-    // never moves -> MIN_TRAJ gate blocks fire.
-    CVState state; cv_init(state);
-    prime_bg(state);
-
-    for (int i = 0; i < 10; i++) {
-        uint8_t f[CV_PIXELS]; draw_walker(f, 0, 95, 48, 5);
-        cv_process(state, f, 50);
-    }
-    quiesce(state);
-
-    TEST_ASSERT_EQUAL_INT(0, state.entries);
-    TEST_ASSERT_EQUAL_INT(0, state.exits);
-}
-
-// Wait out the refractory period with bg-only frames so the next walker
-// event is accepted.
-static void wait_refractory(CVState& state) {
     uint8_t bg[CV_PIXELS]; fill_frame(bg, 100);
-    for (uint32_t i = 0; i < CV_EVENT_REFRACTORY_FRAMES + 2; i++) {
-        cv_process(state, bg, 50);
+    cv_process(state, bg);
+
+    // Walk blob from y=76 toward line; crossing occurs at y=34 (below→above)
+    // Stop at crossing frame and assert its result
+    int setup[] = {76, 62, 48};
+    for (int i = 0; i < 3; i++) {
+        uint8_t f[CV_PIXELS]; make_blob_frame(f, 48, setup[i]);
+        cv_process(state, f);
     }
+    uint8_t fcross[CV_PIXELS]; make_blob_frame(fcross, 48, 34);
+    CVResult r = cv_process(state, fcross);
+
+    TEST_ASSERT_EQUAL_INT(0, r.entries_delta);
+    TEST_ASSERT_EQUAL_INT(1, r.exits_delta);
 }
 
-void test_two_sequential_walkers_count_twice() {
-    CVState state; cv_init(state);
-    prime_bg(state);
+void test_cv_init_populates_tuning_defaults() {
+    CVState state;
+    // Pre-pollute to make sure cv_init overwrites
+    state.tuning.diff_thresh = 0;
+    state.tuning.min_blob_px = 0;
+    state.tuning.max_move    = 0.0f;
+    state.tuning.max_missed  = 0;
+    state.tuning.line_offset = 0;
+    state.tuning.cfg_version = 0xDEADBEEF;
 
-    int rows[][2] = {{60,95},{30,95},{0,95},{0,60},{0,25},{0,10}};
-    for (int i = 0; i < 6; i++) {
-        uint8_t f[CV_PIXELS]; draw_walker(f, rows[i][0], rows[i][1], 48, 5);
-        cv_process(state, f, 50);
-    }
-    quiesce(state);
-    wait_refractory(state);
+    cv_init(state);
 
-    for (int i = 0; i < 6; i++) {
-        uint8_t f[CV_PIXELS]; draw_walker(f, rows[i][0], rows[i][1], 48, 5);
-        cv_process(state, f, 50);
-    }
-    quiesce(state);
-
-    TEST_ASSERT_EQUAL_INT(2, state.entries);
-    TEST_ASSERT_EQUAL_INT(0, state.exits);
+    // Values mirror CV_DEFAULT_* constants in cv.cpp (now file-local).
+    TEST_ASSERT_EQUAL_UINT8(30,     state.tuning.diff_thresh);
+    TEST_ASSERT_EQUAL_INT(64,       state.tuning.min_blob_px);
+    TEST_ASSERT_EQUAL_FLOAT(15.0f,  state.tuning.max_move);
+    TEST_ASSERT_EQUAL_INT(10,       state.tuning.max_missed);
+    TEST_ASSERT_EQUAL_UINT8(50,     state.tuning.line_offset);
+    TEST_ASSERT_EQUAL_UINT32(0,     state.tuning.cfg_version);
 }
 
-void test_full_reversal_counts_entry_then_exit() {
-    CVState state; cv_init(state);
-    prime_bg(state);
+void test_cv_process_respects_runtime_min_blob() {
+    // Proves cv_process reads min_blob_px from state.tuning at runtime
+    // (not from a compile-time constant). With a very high threshold, the
+    // same blob-producing frame that spawns a track in other tests must NOT
+    // spawn one here.
+    CVState state;
+    cv_init(state);
+    state.tuning.min_blob_px = 10000; // larger than CV_PIXELS → no blob can qualify
 
-    int up_rows[][2]   = {{60,95},{30,95},{0,95},{0,60},{0,25},{0,10}};
-    int down_rows[][2] = {{0,35},{0,65},{0,95},{35,95},{70,95},{85,95}};
+    uint8_t bg[CV_PIXELS];
+    fill_frame(bg, 100);
+    cv_process(state, bg); // init background
 
-    for (int i = 0; i < 6; i++) {
-        uint8_t f[CV_PIXELS]; draw_walker(f, up_rows[i][0], up_rows[i][1], 48, 5);
-        cv_process(state, f, 50);
-    }
-    quiesce(state);
-    wait_refractory(state);
+    // Same 30x30 blob used by test_tracking_spawns_track_for_new_blob
+    uint8_t blob_frame[CV_PIXELS];
+    fill_frame(blob_frame, 100);
+    for (int y = 5; y < 35; y++)
+        for (int x = 5; x < 35; x++)
+            blob_frame[y * CV_W + x] = 200;
 
-    for (int i = 0; i < 6; i++) {
-        uint8_t f[CV_PIXELS]; draw_walker(f, down_rows[i][0], down_rows[i][1], 48, 5);
-        cv_process(state, f, 50);
-    }
-    quiesce(state);
+    CVResult r = cv_process(state, blob_frame);
 
-    TEST_ASSERT_EQUAL_INT(1, state.entries);
-    TEST_ASSERT_EQUAL_INT(1, state.exits);
+    TEST_ASSERT_EQUAL_INT(0, (int)state.tracks.size());
+    TEST_ASSERT_EQUAL_INT(0, r.entries_delta);
+    TEST_ASSERT_EQUAL_INT(0, r.exits_delta);
 }
 
-void test_refractory_suppresses_back_to_back_fire() {
-    // After a fire, a second event attempted within CV_EVENT_REFRACTORY_FRAMES
-    // is suppressed. Simulates walker lingering / ghost re-triggering.
-    CVState state; cv_init(state);
-    prime_bg(state);
-
-    int rows[][2] = {{60,95},{30,95},{0,95},{0,60},{0,25},{0,10}};
-    for (int i = 0; i < 6; i++) {
-        uint8_t f[CV_PIXELS]; draw_walker(f, rows[i][0], rows[i][1], 48, 5);
-        cv_process(state, f, 50);
-    }
-    quiesce(state);
-    TEST_ASSERT_EQUAL_INT(1, state.entries);
-
-    // Immediate second walker within refractory window — should NOT count.
-    for (int i = 0; i < 6; i++) {
-        uint8_t f[CV_PIXELS]; draw_walker(f, rows[i][0], rows[i][1], 48, 5);
-        cv_process(state, f, 50);
-    }
-    quiesce(state);
-    TEST_ASSERT_EQUAL_INT(1, state.entries);
+// Helper: init tuning to defaults (via cv_init) with cfg_version = 1
+static CVTuning make_default_tuning() {
+    CVState s;
+    cv_init(s);
+    s.tuning.cfg_version = 1;
+    return s.tuning;
 }
 
-void test_event_counts_after_refractory_expires() {
-    CVState state; cv_init(state);
-    prime_bg(state);
+void test_cv_tuning_validate_accepts_defaults() {
+    CVTuning t = make_default_tuning();
+    TEST_ASSERT_TRUE(cv_tuning_validate(t));
+}
 
-    int rows[][2] = {{60,95},{30,95},{0,95},{0,60},{0,25},{0,10}};
-    for (int i = 0; i < 6; i++) {
-        uint8_t f[CV_PIXELS]; draw_walker(f, rows[i][0], rows[i][1], 48, 5);
-        cv_process(state, f, 50);
-    }
-    quiesce(state);
-    TEST_ASSERT_EQUAL_INT(1, state.entries);
+void test_cv_tuning_validate_rejects_zero_version() {
+    CVTuning t = make_default_tuning();
+    t.cfg_version = 0;
+    TEST_ASSERT_FALSE(cv_tuning_validate(t));
+}
+
+void test_cv_tuning_validate_rejects_each_boundary() {
+    // diff_thresh: 5–120
+    { CVTuning t = make_default_tuning(); t.diff_thresh = 4;   TEST_ASSERT_FALSE(cv_tuning_validate(t)); }
+    { CVTuning t = make_default_tuning(); t.diff_thresh = 121; TEST_ASSERT_FALSE(cv_tuning_validate(t)); }
+    // min_blob_px: 16–4096
+    { CVTuning t = make_default_tuning(); t.min_blob_px = 15;   TEST_ASSERT_FALSE(cv_tuning_validate(t)); }
+    { CVTuning t = make_default_tuning(); t.min_blob_px = 4097; TEST_ASSERT_FALSE(cv_tuning_validate(t)); }
+    // max_move: 2.0–50.0
+    { CVTuning t = make_default_tuning(); t.max_move = 1.9f;  TEST_ASSERT_FALSE(cv_tuning_validate(t)); }
+    { CVTuning t = make_default_tuning(); t.max_move = 50.1f; TEST_ASSERT_FALSE(cv_tuning_validate(t)); }
+    // max_missed: 1–60
+    { CVTuning t = make_default_tuning(); t.max_missed = 0;  TEST_ASSERT_FALSE(cv_tuning_validate(t)); }
+    { CVTuning t = make_default_tuning(); t.max_missed = 61; TEST_ASSERT_FALSE(cv_tuning_validate(t)); }
+    // line_offset: 0–100 (uint8 so only upper bound is meaningful)
+    { CVTuning t = make_default_tuning(); t.line_offset = 101; TEST_ASSERT_FALSE(cv_tuning_validate(t)); }
+
+    // Sanity: inclusive mins/maxes still pass
+    { CVTuning t = make_default_tuning(); t.diff_thresh = 5;    TEST_ASSERT_TRUE(cv_tuning_validate(t)); }
+    { CVTuning t = make_default_tuning(); t.diff_thresh = 120;  TEST_ASSERT_TRUE(cv_tuning_validate(t)); }
+    { CVTuning t = make_default_tuning(); t.min_blob_px = 16;   TEST_ASSERT_TRUE(cv_tuning_validate(t)); }
+    { CVTuning t = make_default_tuning(); t.min_blob_px = 4096; TEST_ASSERT_TRUE(cv_tuning_validate(t)); }
+    { CVTuning t = make_default_tuning(); t.max_move    = 2.0f; TEST_ASSERT_TRUE(cv_tuning_validate(t)); }
+    { CVTuning t = make_default_tuning(); t.max_move    = 50.0f;TEST_ASSERT_TRUE(cv_tuning_validate(t)); }
+    { CVTuning t = make_default_tuning(); t.max_missed  = 1;    TEST_ASSERT_TRUE(cv_tuning_validate(t)); }
+    { CVTuning t = make_default_tuning(); t.max_missed  = 60;   TEST_ASSERT_TRUE(cv_tuning_validate(t)); }
+    { CVTuning t = make_default_tuning(); t.line_offset = 0;    TEST_ASSERT_TRUE(cv_tuning_validate(t)); }
+    { CVTuning t = make_default_tuning(); t.line_offset = 100;  TEST_ASSERT_TRUE(cv_tuning_validate(t)); }
+}
+
+void test_no_crossing_same_side_no_count() {
+    CVState state;
+    cv_init(state);
 
-    // Wait out the refractory period.
     uint8_t bg[CV_PIXELS]; fill_frame(bg, 100);
-    for (uint32_t i = 0; i < CV_EVENT_REFRACTORY_FRAMES + 2; i++) {
-        cv_process(state, bg, 50);
-    }
+    cv_process(state, bg);
 
-    // Second walker — should now count.
-    for (int i = 0; i < 6; i++) {
-        uint8_t f[CV_PIXELS]; draw_walker(f, rows[i][0], rows[i][1], 48, 5);
-        cv_process(state, f, 50);
-    }
-    quiesce(state);
-    TEST_ASSERT_EQUAL_INT(2, state.entries);
-}
+    uint8_t f1[CV_PIXELS]; make_blob_frame(f1, 48, 20); // above line
+    cv_process(state, f1);
 
-void test_noise_below_enter_thresh_does_not_start_event() {
-    // Tiny 5x5 blob (25 px) never crosses ENTER=300, event never starts.
-    CVState state; cv_init(state);
-    prime_bg(state);
+    uint8_t f2[CV_PIXELS]; make_blob_frame(f2, 48, 30); // still above line, moved closer
+    CVResult r = cv_process(state, f2);
 
-    auto small = [](uint8_t* f, int cy) {
-        fill_frame(f, 100);
-        for (int y = cy-2; y <= cy+2; y++)
-            for (int x = 46; x <= 50; x++)
-                if (y>=0 && y<CV_H && x>=0 && x<CV_W) f[y*CV_W+x] = 200;
-    };
-    for (int cy = 10; cy <= 90; cy += 8) {
-        uint8_t f[CV_PIXELS]; small(f, cy);
-        cv_process(state, f, 50);
-    }
-    quiesce(state);
-
-    TEST_ASSERT_EQUAL_INT(0, state.entries);
-    TEST_ASSERT_EQUAL_INT(0, state.exits);
+    TEST_ASSERT_EQUAL_INT(0, r.entries_delta);
+    TEST_ASSERT_EQUAL_INT(0, r.exits_delta);
 }
 
 int main() {
     UNITY_BEGIN();
-    RUN_TEST(test_no_change_no_event);
+    RUN_TEST(test_frame_diff_no_change_gives_no_fg);
+    RUN_TEST(test_frame_diff_large_change_detected_no_crash);
     RUN_TEST(test_cv_init_clears_state);
     RUN_TEST(test_cv_reset_counts);
-    RUN_TEST(test_walker_up_through_frame_is_entry);
-    RUN_TEST(test_walker_down_through_frame_is_exit);
-    RUN_TEST(test_approach_retreat_without_full_extent_does_not_fire);
-    RUN_TEST(test_brief_burst_below_min_duration_does_not_fire);
-    RUN_TEST(test_stationary_large_blob_does_not_fire);
-    RUN_TEST(test_two_sequential_walkers_count_twice);
-    RUN_TEST(test_full_reversal_counts_entry_then_exit);
-    RUN_TEST(test_refractory_suppresses_back_to_back_fire);
-    RUN_TEST(test_event_counts_after_refractory_expires);
-    RUN_TEST(test_noise_below_enter_thresh_does_not_start_event);
+    RUN_TEST(test_tracking_spawns_track_for_new_blob);
+    RUN_TEST(test_blob_crossing_line_top_to_bottom_is_entry);
+    RUN_TEST(test_blob_crossing_line_bottom_to_top_is_exit);
+    RUN_TEST(test_no_crossing_same_side_no_count);
+    RUN_TEST(test_cv_init_populates_tuning_defaults);
+    RUN_TEST(test_cv_process_respects_runtime_min_blob);
+    RUN_TEST(test_cv_tuning_validate_accepts_defaults);
+    RUN_TEST(test_cv_tuning_validate_rejects_zero_version);
+    RUN_TEST(test_cv_tuning_validate_rejects_each_boundary);
     return UNITY_END();
 }

tools/capture_frames.py

@@ -1,105 +0,0 @@
-#!/usr/bin/env python3
-# tools/capture_frames.py
-#
-# Read framed 96x96 grayscale frames from the capture-mode firmware over serial
-# and write them to a .bin file for offline replay.
-#
-# Wire format per frame (little-endian):
-#   magic    u32  0xDC0FC0DE
-#   frame_ix u32
-#   millis   u32
-#   pixels   9216 bytes
-#
-# Output file is the raw concatenation of frames (same layout as the wire),
-# so replay_frames.py can stream it with identical parsing.
-#
-# Usage: python tools/capture_frames.py --port /dev/ttyUSB0 --out walk.bin --duration 60
-
-import argparse
-import serial
-import struct
-import sys
-import time
-
-MAGIC = 0x314D5246  # 'FRM1' — ascii bytes that survive the CH9102 stream
-FRAME_PIXELS = 96 * 96
-HEADER_LEN = 12
-FRAME_LEN = HEADER_LEN + FRAME_PIXELS
-
-
-def read_exact(ser, n):
-    buf = bytearray()
-    while len(buf) < n:
-        chunk = ser.read(n - len(buf))
-        if not chunk:
-            return None
-        buf.extend(chunk)
-    return bytes(buf)
-
-
-def find_magic(ser):
-    """Scan serial byte-by-byte until we see the 4-byte MAGIC."""
-    window = bytearray()
-    magic_bytes = struct.pack('<I', MAGIC)
-    while True:
-        b = ser.read(1)
-        if not b:
-            return False
-        window.extend(b)
-        if len(window) > 4:
-            del window[0]
-        if bytes(window) == magic_bytes:
-            return True
-
-
-def main():
-    ap = argparse.ArgumentParser()
-    ap.add_argument('--port', required=True)
-    ap.add_argument('--baud', type=int, default=460800)
-    ap.add_argument('--out',  required=True)
-    ap.add_argument('--duration', type=float, default=60.0,
-                    help='Seconds to capture (default 60)')
-    args = ap.parse_args()
-
-    ser = serial.Serial(args.port, args.baud, timeout=1.0)
-    print(f'# listening on {args.port} @ {args.baud} for {args.duration}s...',
-          file=sys.stderr)
-
-    # Drain boot banner lines.
-    deadline_banner = time.time() + 2.0
-    while time.time() < deadline_banner:
-        line = ser.readline()
-        if line.startswith(b'#'):
-            print(line.decode(errors='replace').rstrip(), file=sys.stderr)
-        if b'capture-mode' in line:
-            break
-
-    deadline = time.time() + args.duration
-    frames = 0
-    last_ix = None
-    dropped = 0
-
-    with open(args.out, 'wb') as f:
-        while time.time() < deadline:
-            if not find_magic(ser):
-                continue
-            body = read_exact(ser, 8 + FRAME_PIXELS)
-            if body is None:
-                break
-            frame_ix, ms = struct.unpack('<II', body[:8])
-            if last_ix is not None and frame_ix != last_ix + 1:
-                dropped += frame_ix - last_ix - 1
-            last_ix = frame_ix
-            f.write(struct.pack('<I', MAGIC))
-            f.write(body)
-            frames += 1
-            if frames % 25 == 0:
-                print(f'# {frames} frames, last ix={frame_ix} ms={ms} '
-                      f'dropped={dropped}', file=sys.stderr)
-
-    print(f'# done: {frames} frames written to {args.out} '
-          f'({dropped} dropped)', file=sys.stderr)
-
-
-if __name__ == '__main__':
-    main()

tools/replay_frames.py

@@ -1,211 +0,0 @@
-#!/usr/bin/env python3
-# tools/replay_frames.py
-#
-# Offline Python port of the event-based CV detector (firmware/lib/cv/cv.cpp).
-# Reads a .bin file produced by capture_frames.py and prints events.
-#
-# Purpose: iterate algorithm changes in seconds instead of minutes. All
-# constants match cv.h so baseline behavior matches firmware.
-#
-# Usage:
-#   python tools/replay_frames.py walk.bin
-#   python tools/replay_frames.py walk.bin --enter 250 --exit 150 --max 25
-#
-# Output: one line per frame with fg diagnostics, plus [ENTRY]/[EXIT] lines
-# when the detector fires.
-
-import argparse
-import struct
-import sys
-
-import numpy as np
-
-MAGIC = 0x314D5246  # 'FRM1'
-W = H = 96
-PIXELS = W * H
-HEADER = 12
-FRAME_LEN = HEADER + PIXELS
-
-
-class Detector:
-    """Mirror of firmware CV state machine. Single walker events, centroid
-    trajectory direction. Only per-frame fg_count + min/max y + centroid y
-    feed the decision — per-blob tracks are diagnostic in firmware, dropped
-    here."""
-
-    def __init__(self, args):
-        self.a = args
-        self.bg = None
-        self.ev_active = False
-        self.ev_frames = 0
-        self.ev_first_c = -1.0
-        self.ev_last_c  = -1.0
-        self.ev_min_c   = float(H)
-        self.ev_max_c   = -1.0
-        self.ev_min_y   = H
-        self.ev_max_y   = -1
-        self.ev_quiet   = 0
-        self.last_fire  = 0
-        self.frame_ix   = 0
-        self.entries    = 0
-        self.exits      = 0
-
-    def _reset_event(self):
-        self.ev_active = False
-        self.ev_frames = 0
-        self.ev_first_c = self.ev_last_c = -1.0
-        self.ev_min_c = float(H)
-        self.ev_max_c = -1.0
-        self.ev_min_y = H
-        self.ev_max_y = -1
-        self.ev_quiet = 0
-
-    def _finalize(self):
-        a = self.a
-        if self.ev_frames < a.min_frames: return None
-        if self.ev_min_y  > a.extent_top: return None
-        if self.ev_max_y  < a.extent_bot: return None
-        up   = self.ev_first_c - self.ev_min_c
-        down = self.ev_max_c   - self.ev_first_c
-        winning = max(up, down)
-        if winning < a.min_traj: return None
-        is_entry = up >= down
-        self.last_fire = self.frame_ix
-        info = dict(
-            kind='ENTRY' if is_entry else 'EXIT',
-            first=self.ev_first_c, min=self.ev_min_c,
-            max=self.ev_max_c, last=self.ev_last_c,
-            dur=self.ev_frames,
-        )
-        if is_entry: self.entries += 1
-        else:        self.exits   += 1
-        return info
-
-    def step(self, frame):
-        """frame: uint8 array of shape (H, W). Returns list of fire dicts."""
-        self.frame_ix += 1
-        fires = []
-
-        if self.bg is None:
-            self.bg = frame.astype(np.int16)
-            return fires
-
-        bg = self.bg.astype(np.int16)
-        diff = np.abs(frame.astype(np.int16) - bg)
-        fg = (diff > self.a.diff_thresh).astype(np.uint8)
-
-        # Running-avg bg blend, frozen during active event.
-        if not self.ev_active:
-            self.bg = ((self.bg * 31 + frame.astype(np.int16)) >> 5)
-
-        fg_count = int(fg.sum())
-        if fg_count > 0:
-            row_counts = fg.sum(axis=1)
-            ys = np.where(row_counts > 0)[0]
-            min_y = int(ys.min())
-            max_y = int(ys.max())
-            centroid_y = float((row_counts * np.arange(H)).sum() / fg_count)
-        else:
-            min_y, max_y, centroid_y = -1, -1, -1.0
-
-        # Self-heal on catastrophic bg mismatch.
-        if fg_count > PIXELS // 2:
-            self.bg = frame.astype(np.int16)
-            if self.ev_active: self._reset_event()
-            return fires
-
-        a = self.a
-        in_refractory = (self.last_fire != 0 and
-                         (self.frame_ix - self.last_fire) < a.refractory)
-
-        if not self.ev_active:
-            if not in_refractory and fg_count >= a.enter_thresh:
-                self.ev_active  = True
-                self.ev_frames  = 1
-                self.ev_first_c = centroid_y
-                self.ev_last_c  = centroid_y
-                self.ev_min_c   = centroid_y
-                self.ev_max_c   = centroid_y
-                self.ev_min_y   = min_y
-                self.ev_max_y   = max_y
-                self.ev_quiet   = 0
-        else:
-            self.ev_frames += 1
-            if fg_count > 0:
-                self.ev_last_c = centroid_y
-                if centroid_y < self.ev_min_c: self.ev_min_c = centroid_y
-                if centroid_y > self.ev_max_c: self.ev_max_c = centroid_y
-                if min_y < self.ev_min_y: self.ev_min_y = min_y
-                if max_y > self.ev_max_y: self.ev_max_y = max_y
-
-            ended = False
-            if fg_count < a.exit_thresh:
-                self.ev_quiet += 1
-                if self.ev_quiet >= a.quiet_frames:
-                    ended = True
-            else:
-                self.ev_quiet = 0
-                if self.ev_frames > a.max_frames:
-                    ended = True
-
-            if ended:
-                fire = self._finalize()
-                if fire: fires.append(fire)
-                self._reset_event()
-                self.bg = frame.astype(np.int16)
-
-        return fires, fg_count, min_y, max_y, centroid_y
-
-
-def iter_frames(path):
-    with open(path, 'rb') as f:
-        data = f.read()
-    n = len(data) // FRAME_LEN
-    for i in range(n):
-        off = i * FRAME_LEN
-        magic, ix, ms = struct.unpack('<III', data[off:off + HEADER])
-        if magic != MAGIC:
-            raise RuntimeError(f'bad magic at frame {i}: 0x{magic:08x}')
-        frame = np.frombuffer(data, dtype=np.uint8,
-                              count=PIXELS, offset=off + HEADER).reshape(H, W)
-        yield ix, ms, frame
-
-
-def main():
-    ap = argparse.ArgumentParser()
-    ap.add_argument('path')
-    ap.add_argument('--diff-thresh', dest='diff_thresh', type=int, default=30)
-    ap.add_argument('--enter', dest='enter_thresh', type=int, default=300)
-    ap.add_argument('--exit',  dest='exit_thresh',  type=int, default=200)
-    ap.add_argument('--quiet', dest='quiet_frames', type=int, default=3)
-    ap.add_argument('--min',   dest='min_frames',   type=int, default=5)
-    ap.add_argument('--max',   dest='max_frames',   type=int, default=25)
-    ap.add_argument('--extent-top', dest='extent_top', type=int, default=10)
-    ap.add_argument('--extent-bot', dest='extent_bot', type=int, default=85)
-    ap.add_argument('--min-traj', dest='min_traj', type=float, default=15.0)
-    ap.add_argument('--refractory', dest='refractory', type=int, default=15)
-    ap.add_argument('--quiet-log', action='store_true',
-                    help='Suppress per-frame fg lines')
-    args = ap.parse_args()
-
-    det = Detector(args)
-    total = 0
-    for ix, ms, frame in iter_frames(args.path):
-        total += 1
-        out = det.step(frame)
-        if out == []:
-            if not args.quiet_log:
-                print(f'[{ix:4d}] bg init')
-            continue
-        fires, fg, miny, maxy, cy = out
-        if not args.quiet_log and fg > 0:
-            print(f'[{ix:4d}] n={fg:4d} y={miny:2d}..{maxy:2d} c={cy:5.1f}')
-        for fire in fires:
-            print(f'  >>> {fire["kind"]} first={fire["first"]:.1f} '
-                  f'min={fire["min"]:.1f} max={fire["max"]:.1f} '
-                  f'last={fire["last"]:.1f} dur={fire["dur"]}')
-    print(f'\n# {total} frames  entries={det.entries}  exits={det.exits}')
-
-
-if __name__ == '__main__':
-    main()

tools/replay_logs.py

@@ -1,186 +0,0 @@
-#!/usr/bin/env python3
-# tools/replay_logs.py
-#
-# Replay the event state machine against text serial logs captured from the
-# production firmware. Input lines of the form:
-#   [F] n=<fg_count> y=<min_y>..<max_y> c=<centroid_y>
-#
-# Those four values are exactly what the firmware's event state machine
-# consumes — so we can iterate event-level params (thresholds, max_frames,
-# extent gates, trajectory cutoffs, refractory) offline without needing raw
-# frames or the device.
-#
-# Usage:
-#   python tools/replay_logs.py walk.log
-#   python tools/replay_logs.py walk.log --enter 250 --exit 100 --max 30 --min-traj 10
-#   cat walk.log | python tools/replay_logs.py - --ground-truth 12
-
-import argparse
-import re
-import sys
-
-
-LINE_RE = re.compile(
-    r'\[F\]\s+n=(?P<n>\d+)\s+y=(?P<miny>-?\d+)\.\.(?P<maxy>-?\d+)\s+c=(?P<c>-?\d+\.\d+)'
-)
-
-
-def parse_frames(text):
-    """Yield (fg_count, min_y, max_y, centroid_y) per [F] line, in order."""
-    for line in text.splitlines():
-        m = LINE_RE.search(line)
-        if not m:
-            continue
-        yield int(m['n']), int(m['miny']), int(m['maxy']), float(m['c'])
-
-
-class Detector:
-    """Mirror of firmware event state machine. Only uses per-frame diagnostic
-    values — the same inputs the firmware feeds it."""
-
-    def __init__(self, a):
-        self.a = a
-        self.ev = False
-        self.ev_n = 0
-        self.ev_first = self.ev_last = -1.0
-        self.ev_min = 1e9
-        self.ev_max = -1.0
-        self.ev_miny = 1e9
-        self.ev_maxy = -1
-        self.ev_quiet = 0
-        self.last_fire = -10**9
-        self.ix = 0
-        self.entries = 0
-        self.exits = 0
-        self.fires = []
-
-    def _reset(self):
-        self.ev = False
-        self.ev_n = 0
-        self.ev_first = self.ev_last = -1.0
-        self.ev_min = 1e9; self.ev_max = -1.0
-        self.ev_miny = 1e9; self.ev_maxy = -1
-        self.ev_quiet = 0
-
-    def _finalize(self):
-        a = self.a
-        if self.ev_n < a.min_frames:
-            return ('reject_short', None)
-        if self.ev_miny > a.extent_top:
-            return ('reject_extent_top', None)
-        if self.ev_maxy < a.extent_bot:
-            return ('reject_extent_bot', None)
-        up   = self.ev_first - self.ev_min
-        down = self.ev_max   - self.ev_first
-        winning = max(up, down)
-        if winning < a.min_traj:
-            return ('reject_traj', None)
-        timed_out = self.ev_n > a.max_frames
-        if timed_out:
-            is_entry = self.ev_last < self.ev_first
-        else:
-            is_entry = up >= down
-        kind = 'ENTRY' if is_entry else 'EXIT'
-        self.last_fire = self.ix
-        info = dict(kind=kind, first=self.ev_first, min=self.ev_min,
-                    max=self.ev_max, last=self.ev_last, dur=self.ev_n,
-                    up=up, down=down, ix=self.ix)
-        if is_entry: self.entries += 1
-        else:        self.exits   += 1
-        self.fires.append(info)
-        return ('fire', info)
-
-    def step(self, n, miny, maxy, c):
-        self.ix += 1
-        a = self.a
-        refractory = (self.ix - self.last_fire) < a.refractory
-
-        if not self.ev:
-            if not refractory and n >= a.enter_thresh:
-                self.ev = True
-                self.ev_n = 1
-                self.ev_first = self.ev_last = c
-                self.ev_min = c; self.ev_max = c
-                self.ev_miny = miny; self.ev_maxy = maxy
-                self.ev_quiet = 0
-            return None
-
-        self.ev_n += 1
-        if n > 0:
-            self.ev_last = c
-            if c < self.ev_min: self.ev_min = c
-            if c > self.ev_max: self.ev_max = c
-            if miny < self.ev_miny: self.ev_miny = miny
-            if maxy > self.ev_maxy: self.ev_maxy = maxy
-
-        ended = False
-        if n < a.exit_thresh:
-            self.ev_quiet += 1
-            if self.ev_quiet >= a.quiet_frames:
-                ended = True
-                reason = 'quiet'
-        else:
-            self.ev_quiet = 0
-            if self.ev_n > a.max_frames:
-                ended = True
-                reason = 'timeout'
-
-        if ended:
-            result = self._finalize()
-            self._reset()
-            return (reason, result)
-        return None
-
-
-def main():
-    ap = argparse.ArgumentParser()
-    ap.add_argument('path', help='log file, or - for stdin')
-    ap.add_argument('--enter',      dest='enter_thresh', type=int,   default=300)
-    ap.add_argument('--exit',       dest='exit_thresh',  type=int,   default=200)
-    ap.add_argument('--quiet',      dest='quiet_frames', type=int,   default=3)
-    ap.add_argument('--min',        dest='min_frames',   type=int,   default=5)
-    ap.add_argument('--max',        dest='max_frames',   type=int,   default=25)
-    ap.add_argument('--extent-top', dest='extent_top',   type=int,   default=10)
-    ap.add_argument('--extent-bot', dest='extent_bot',   type=int,   default=85)
-    ap.add_argument('--min-traj',   dest='min_traj',     type=float, default=15.0)
-    ap.add_argument('--refractory', dest='refractory',   type=int,   default=15)
-    ap.add_argument('--ground-truth', type=int, default=0,
-                    help='Total expected walks for accuracy calc')
-    ap.add_argument('-v', '--verbose', action='store_true',
-                    help='Print every event end, including rejections')
-    args = ap.parse_args()
-
-    text = sys.stdin.read() if args.path == '-' else open(args.path).read()
-
-    det = Detector(args)
-    rejects = {}
-    for n, miny, maxy, c in parse_frames(text):
-        out = det.step(n, miny, maxy, c)
-        if out is None:
-            continue
-        reason, result = out
-        if result is None:
-            continue
-        kind, info = result
-        if kind == 'fire':
-            print(f'  {info["kind"]:5}  first={info["first"]:5.1f}  '
-                  f'min={info["min"]:5.1f}  max={info["max"]:5.1f}  '
-                  f'last={info["last"]:5.1f}  dur={info["dur"]:2d}  '
-                  f'exit={reason}')
-        else:
-            rejects[kind] = rejects.get(kind, 0) + 1
-            if args.verbose:
-                print(f'  [drop {kind}]')
-
-    total = det.entries + det.exits
-    print(f'\n=== entries={det.entries}  exits={det.exits}  total={total} ===')
-    print(f'rejected events: {rejects}')
-    if args.ground_truth:
-        gt = args.ground_truth
-        acc = min(total, gt) / gt * 100
-        over = max(0, total - gt)
-        print(f'accuracy vs gt={gt}: {acc:.0f}% (over={over})')
-
-
-if __name__ == '__main__':
-    main()

tools/serial_monitor.py

@@ -1,56 +0,0 @@
-#!/usr/bin/env python3
-# Serial monitor for ESP32. Optionally pulses RTS/DTR to reset the device
-# so we capture boot output. Prefixes each line with elapsed seconds.
-import serial, sys, time, argparse
-
-def main():
-    ap = argparse.ArgumentParser()
-    ap.add_argument("--port",    default="/dev/ttyUSB0")
-    ap.add_argument("--baud",    type=int, default=115200)
-    ap.add_argument("--seconds", type=int, default=20)
-    ap.add_argument("--reset",   action="store_true",
-                    help="Pulse RTS/DTR to reset the ESP32 before reading")
-    ap.add_argument("--timestamp", action="store_true",
-                    help="Prefix each line with elapsed seconds since boot")
-    args = ap.parse_args()
-
-    try:
-        s = serial.Serial(args.port, args.baud, timeout=0.2,
-                          rtscts=False, dsrdtr=False)
-    except Exception as e:
-        print(f"[open-fail] {e}", flush=True)
-        sys.exit(2)
-
-    if args.reset:
-        s.setDTR(False)
-        s.setRTS(True)
-        time.sleep(0.1)
-        s.setRTS(False)
-        s.reset_input_buffer()
-
-    t0 = time.time()
-    end = t0 + args.seconds
-    buf = b""
-    while time.time() < end:
-        chunk = s.read(512)
-        if chunk:
-            buf += chunk
-            while b"\n" in buf:
-                line, buf = buf.split(b"\n", 1)
-                text = line.decode("utf-8", errors="replace").rstrip("\r")
-                if args.timestamp:
-                    sys.stdout.write(f"[{time.time()-t0:5.1f}s] {text}\n")
-                else:
-                    sys.stdout.write(text + "\n")
-                sys.stdout.flush()
-    if buf:
-        text = buf.decode("utf-8", errors="replace")
-        if args.timestamp:
-            sys.stdout.write(f"[{time.time()-t0:5.1f}s] {text}\n")
-        else:
-            sys.stdout.write(text)
-        sys.stdout.flush()
-    s.close()
-
-if __name__ == "__main__":
-    main()