Files
parking_solution/wiki/concepts/entry-exit-readers.md
T
julian 1efa77bf56 devices: pool-of-spaces model — drop lane, per-relay direction
A parking lot is one pool of spaces with a flexible set of entry/exit
points — no "lane". Direction is a property of each RELAY inside an access
controller; readers/cameras bind to a controller relay and inherit it.

Schema:
- drop `lane` from ledger_events, device_events, sessions
- rename lane_devices -> devices (no lane/direction columns)
- access config.relays=[{relay,direction,button?}]; reader/camera
  config.controllerId+relay binding
- fresh 0000_baseline migration (history reset; dev data was throwaway)

Signed ledger:
- remove `lane` from canonicalize(); bump signer keyId sw-hmac-v1 -> v2
  (v1 events won't verify under v2 — intentional, gated per-event by keyId)

Server:
- new device-resolve.ts (replaces lane-map.ts): relayForButton,
  relayForDevice, firstRelayByDirection, devicesByDirection
- entry-flow: button terminal -> its relay; exit/permit: reader's bound
  relay; dispatcher resolves the bound relay + inherited direction
- camera snapshots fire by direction site-wide, async, never block open
- DeviceConfig widened to nested JSON for relays[]

Web:
- wizard: no lane selector; add controllers (relay map + entry-button
  terminal) first, then bind readers/cameras/printers to a controller relay

Wiki: new entry-exit-points.md (replaces lane-direction); reworked
entry-exit-readers, parking-session, first-run-setup, device-registry,
append-only-event-chain, device-events; removed stale lane/LaneMap mentions.
2026-06-16 20:29:38 +02:00

2.7 KiB

type, tags, sources, updated
type tags sources updated
concept
parking
architecture
readers
parking-system-architecture
2026-06-14

Entry / Exit Readers

There are two populations of users, and they map to two integration paths. (See parking-system-architecture §8.)

  • Permit holders / subscribers — want hands-free/quick entry. Best served by reads reaching the controller directly (wiegand) so it can decide autonomously (works if host is down).
  • Casual / transient — printed ticket, pay-on-exit, or plate recognition. Inherently host-side identity sources (lpr-camera, QR/ticket scanner).

How reads reach the system

Reader type Who sees the read Decision by Offline autonomy
wiegand reader → UHPPOTE port The controller Controller (onboard card list) Yes — works if host down
Pure TCP/IP reader Host only Host, then UDP open to relay No — host on critical path
[[lpr-camera LPR]] / QR scanner Host only Host
gee-qr-er80 QR reader (serial) Host only Host (reads serial → read bus) No

Concrete host-side reader on hand: the gee-qr-er80 (QR over RS-232/RS-485). Note autonomy is moot here anyway — the current relay (dingtian-relay) has no onboard card list, so even a Wiegand reader would be host-decided. So we take the serial/QR path straight to the host's read bus.

Key points

  • Pure network readers are invisible to the uhppote-controller — it only generates events for its own terminals. For a pure-TCP reader, only the host can listen/decide/command; the controller is demoted to a commanded relay (onboard card DB + offline autonomy bypassed).
  • Check for a Wiegand output first — many "network" readers have both; wiring Wiegand in keeps autonomy + native event log.
  • Both models can share one relay (valid Wiegand read or host open in "controlled" mode), so one lane serves permit + casual.
  • Each reader BINDS to a controller relay (config.controllerId + relay) — the barrier it sits at — and inherits that relay's direction (entry/exit/both). An exit read opens exactly that relay; an entry read the entry relay. This is how separate in/out readers are disambiguated, with no "lane". See entry-exit-points.
  • Host-in-the-loop is good for fraud detection — two independent records (host's signed append-only-event-chain entry + the UHPPOTE remote-open event) should reconcile 1:1; any mismatch is an anomaly.

Autonomy caveat: with remote-host control enabled, the controller expects host comms every ~30 s or reverts to local control (Wiegand-on-board lanes only).