With a switch fitted, an AMS is not wired to a nozzle any more. It is
plumbed into one of the switch's two inlets and reaches both nozzles
through it, so every unit reports its extruder as "not fixed" (0xE) and
ams_extruder_map comes back empty on these machines.
The printer card had nothing to fall back on but the AMS unit number, so
AMS-A was badged R and AMS-B was badged L purely because their unit ids
are 0 and 1, a third unit got no badge at all, and every one of those
labels was wrong. The SpoolBuddy assign modal had the same fallback in a
worse form, mapping anything that was not extruder 1 to R.
The binding turned out to need no new telemetry. BambuStudio reads it out
of bits 24-27 of the same AMS info string we already parse for the AMS
type and the extruder id -- 0 is In-B, 1 is In-A -- and it is only
meaningful when a switch is installed, because without one 0xE really
does mean an uninitialised unit and those bits carry nothing. That gates
the read, which in turn forced the switch block to be parsed before the
AMS block: _handle_ams_data runs early in _process_message and
_update_state only much later, so the binding was lost on every frame
that carried both. _parse_fila_switch is split out and called first, and
left in _update_state as well so that stays a complete absorb step.
The badge keeps L and R rather than A and B, because the lettering is
familiar and matches the physical layout. It is a different colour from
the plain nozzle badge, and its tooltip names the inlet in full, since
the letter is the inlet's position and not a claim about which nozzle
that AMS feeds -- the switch can route either inlet to either outlet. An
AMS still reporting a real extruder id keeps its ordinary badge, which
BambuStudio also treats as authoritative over any switch binding, and a
switch that has been fitted but not yet set up on the printer shows
nothing rather than a guess.
The print dialog's slot dropdown gets the same label. It replaces a
left/right hint that never once rendered: ftsExtruderForSlot compared
snow-encoded in[] values against global tray ids and could not match.
Decoding it correctly would not have saved it -- the firmware reports
which slot sits in each inlet and which nozzle each outlet feeds, but
never which inlet is currently paired with which outlet, so no per-slot
nozzle can be derived. That function is gone rather than fixed.
The dialog also points out when every filament a print needs sits behind
one inlet. Bambu's own guidance is that this is legal but slow: a change
between two filaments on the same inlet retracts the outgoing spool all
the way back to its AMS before the next can be fed up the shared tube,
where a change across the two inlets only retracts as far as the switch.
All on one inlet means every change in the job takes the slow path, and
moving a single spool fixes it. So it advises, it does not block.
Both views update live. Two things were stopping that. fila_switch and
ams_switch_inlet were absent from printer_state_to_dict, and the frontend
shallow-merges each WebSocket push over its cached status, so a field the
push omits keeps whatever the last full fetch left behind. And the
broadcast dedup key had no term for either, so "Join IN-B" on the printer
screen moved nothing: the binding is not in the tray component of that
key, and it is not in the AMS change-hash either, which covers tray
fields only and must stay that way because it drives Spoolman sync.
Assigning an AMS to an inlet remains printer-side. BambuStudio can read
the binding and has no command to write it -- its switch class is parse
and getters only, and the recommended-arrangement popup draws and
publishes nothing -- so there is no wire format for us to copy.
Adding the two fields to PrinterState broke four test modules whose
SimpleNamespace stubs predate them. The stubs are fixed rather than the
production reads made defensive: the real dataclass always carries both,
and a getattr in the dedup key would silently stop tracking the field if
it were ever renamed.
Every pipeline endpoint answered 403 for API keys whatever scopes the key
carried. PR A parked all three permissions on the admin denylist until the
run dispatch existed to decide about; it landed in PR C and the parking was
never revisited.
PIPELINES_READ now rides can_read_status. PIPELINES_RUN requires
can_queue AND can_manage_library together, so the allowlist gained tuple
values: a run slices into the library and then queues prints, and mapping
it to either flag alone would hand that flag the other one's authority.
The 403 names every flag the key is short of. PIPELINES_WRITE stays
admin-only -- a key can run the recipe, not rewrite it or clear the log.
Opening the run route also needed the cloud-owner fallback the direct
slice route makes: a pipeline can carry Bambu/Orca Cloud presets, and
resolving those reads a token off a user record that an API-keyed request
does not have. retry_failed forwards the new dependency explicitly,
since a direct call receives the Depends marker rather than None.
on_printer_status_change builds reconcile_stale_active_prints(...) as a
call argument, so the coroutine is constructed even when the spawn helper
is mocked out. A bare MagicMock retained it in call_args and it finalised
unawaited during a later test's GC, surfacing as a
PytestUnraisableExceptionWarning attributed to test_printer_sensor_history.
Patch spawn_background_task with a side_effect that closes the coroutine,
and correct the _state() docstring, which claimed state="IDLE" kept the
reconcile-edge branch quiescent when it does the opposite.
The progress-milestone and HMS-error notification paths in
on_printer_status_change held a session across the ~15s camera snapshot
taken for the notification image, pinning a pooled connection per
milestone/error per printer.
The snapshot needs no DB: read the printer in a short session, release
it, grab the snapshot with none held, then open a fresh session for the
notification send (and lift the db-free MQTT publish out too). Pinned by
a test that fails if the snapshot runs while a session is open.
Two tightly-coupled deliverables in one drop -- a new AMS Filament Backup
status/control surface, and the #1766 fix that depends on it.
Added -- AMS Filament Backup status + control
- Parse bit 18 of top-level print.cfg into PrinterState.ams_filament_backup
on every push_status. Verified against OrcaSlicer source
(DeviceManager.cpp:4961) and a live H2D ON/OFF capture. Tri-state
(None = A1 family / pre-cfg push) preserves today's behaviour.
- Hold-timer guard (3 s) prevents stale frames from flickering the badge
back to the printer's old cfg after a user-initiated toggle.
- POST /printers/{id}/ams-backup toggle, set_ams_filament_backup() client
method calling _set_print_option("auto_switch_filament", enabled).
- GET /printers/{id}/inventory-remain endpoint exposes the same map the
dispatcher uses (internal and Spoolman modes both work uniformly).
- Small icon badge in the printer card's "Filaments" section header
(placement reads as printer-wide because the cfg bit is printer-wide,
not per-AMS). Click to toggle, success toast.
- 5 i18n keys x 11 locales for the badge UI.
Fixed -- #1766: prefer_lowest didn't pick lowest, ignored backup state
- Backend gate in _compute_ams_mapping_for_printer: coerce prefer_lowest
to False when status.ams_filament_backup is False; log the skip.
- New effectivePreferLowest(setting, backup) helper applied at every
frontend sort entry point: single-printer PrintModal, multi-printer
hook per-printer, PrinterSelector InlineMappingEditor, FilamentMapping
standalone editor (the last had NO preferLowest awareness at all
before this change).
- New preferLowestSortKey(f, inventoryByTrayId) mirrors backend's two-tier
key exactly, including the banding tie-break (regular AMS < AMS-HT <
external) so the client-side pre-compute matches the dispatch-time pick.
An earlier draft used a flat `amsId * 4 + trayId` priority which gave
external slots (ams_id = -1) a NEGATIVE priority -- caught in code
review before commit.
- Settings -> Filament -> "Prefer lowest remaining filament" gets an
explanatory note about the printer-side AMS Backup dependency, with
i18n key in all 11 locales.
The provider toggle, schema, template, and NotificationService.on_printer_offline
all shipped, but no caller invoked the dispatcher — the offline event was an
orphan toggle. Edge detection in on_printer_status_change now schedules a
debounced (60s) background task on the connected→disconnected transition;
reconnect before the window elapses cancels it. Covers both upstream paths
(smart-plug power-off via mark_printer_offline, and MQTT staleness via
check_staleness), both of which already route through the status callback.
The "back online" channel is the existing print-failure notification on
firmware FAILED report — no symmetric on_printer_online needed.
maziggy