Camera in the plan: roadmap Phase 5 split into camera then inference; proposed decisions 27 (live view) and 28 (paced Orin -> tablet senders)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DDwfd6Ki8UfG4hK6W5YpJz

docs/ROADMAP.md

@@ -1,7 +1,7 @@
 ---
 type: plan
 status: active
-updated: 2026-10-09
+updated: 2026-10-11
 ---
 # Roadmap
 
@@ -24,6 +24,9 @@ Getting the Jetson to see the hardware at all.
       documented, sources kept in `~/infra`; still manual, and breaks silently
       if forgotten
 - [x] Network time pinned to NICT; timezone `Asia/Tokyo`
+- [x] USB camera (IMX662, Sunplus UVC bridge) recognised on the car unit with
+      in-tree drivers: MJPEG up to 1080p60, microphone; measured in
+      orin-nano-env-setup `docs/impl/reports/USB-CAMERA.md`
 - [ ] Optional: RTC backup battery (CR2032) — without it the clock boots stale
       until NTP or GPS corrects it
 - [ ] Power and mounting in the car: clean shutdown on ignition off
@@ -79,10 +82,29 @@ Order chosen by feedback speed, not ambition.
       car unit and a text-readout starter app; not yet run on the tablet
 - [ ] `app-esp32` — RLCD/e-ink glanceable subset. Deferred, no hardware in scope
 
-## Phase 5 — Camera and inference · *separate task*
+## Phase 5 — Camera, then inference
 
-Deliberately deferred. It is the reason the compute is a Jetson rather than a
-Pi, but it shares nothing with the CAN work beyond the bus.
+The camera is on the car unit (2026-10-11). Capturing and recording need no
+model and no GPU, so they can come before inference, which stays deferred: it is
+the reason the compute is a Jetson rather than a Pi, but it shares nothing with
+the CAN work beyond the bus, and it competes with voice for memory.
+
+What the hardware gives (USB camera report): MJPEG only, ~7.3 MB/s at 1080p30;
+no hardware video encoder on the Orin Nano, so H.264 is software, ~1.3–2 of 6
+cores at 1080p; frame rate falls with the light.
+
+- [ ] Decide the camera's roles and mounting: dash recording, live view on the
+      tablet, inference input, or several
+- [ ] Measure in the car: daylight and night frame rate and MJPEG size on a road
+      scene
+- [ ] One capture process owns `/dev/video0` (V4L2 is single-reader) and feeds
+      the others; sets UVC controls on open, since they reset on re-enumeration
+- [ ] Recording: H.264 segments on the recorder's clock and session marks,
+      bounded like CAN sessions (~2.7 GB per hour at 6 Mbit/s)
+- [ ] Live view in `app-flutter` (decision 27, proposed): 720p MJPEG passthrough
+      (~3.4 MB/s, no CPU) or H.264, paced per decision 28
+- [ ] Inference — deferred; plan for evicting voice, not for coexisting with it
+      ([ORIN-RUNTIME.md](ORIN-RUNTIME.md))
 
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