fix(spoolbuddy): gate display wake on stable scale reading
A noisy load cell that bounced ≥50 g around its midpoint kept the kiosk
screen permanently lit. The wake threshold check ran against last_wake_grams
which itself advanced to noisy values, so every bounce back across 50 g
re-fired display.wake(), keeping the FIFO reader pumping wlopm --on
faster than swayidle could trigger wlopm --off.
The fix gates wake on the scale's `stable` flag — only readings that
have settled within 2 g over a 1 s window count as a real spool
placement / removal. Unstable noise can't fire wake and can't advance
last_wake_grams, so the next genuine settled change is still measured
against the right baseline.
Three regression tests pin the contract: noisy ±60 g unstable readings
never wake, a settled >50 g jump wakes, a noise burst between two
settled readings doesn't poison last_wake_grams.
Bambuddy's SSH keypair under <DATA_DIR>/spoolbuddy/ssh/ regenerates whenever
the data dir is recreated (volume remount, container recreate, fresh deploy).
The daemon previously only fetched the pubkey at registration, so any
rotation after a successful boot left ~/.ssh/authorized_keys pointing at
a stale public half — every Update click then failed with "Connection
closed by authenticating user spoolbuddy [preauth]" until the daemon was
restarted by hand. Each prior registration also appended a fresh entry
without pruning, accumulating stale Bambuddy-tagged keys indefinitely.
- HeartbeatResponse now carries ssh_public_key; the heartbeat route reads
it via the same try/except shape as the register route so a missing or
unreadable backend key doesn't break telemetry.
- _deploy_ssh_key() strips lines tagged bambuddy-spoolbuddy and writes
the current key once. No-op when already in sync (no mtime churn on
every heartbeat). User-managed entries are preserved.
- Daemon heartbeat handler calls _deploy_ssh_key when the response
carries a key, so rotations propagate within one heartbeat instead
of requiring a service restart.
Tests: 5 unit (creates-when-missing, replace-stale-pileup, preserve-user-keys,
idempotent, swallows-write-errors) + 2 backend integration (heartbeat carries
the key; backend key-read failure leaves ssh_public_key None but the
heartbeat still 200s).
Display now powers on via wlopm when the daemon detects an NFC tag or
a significant weight change (>=50g, i.e. spool placed/removed) while
the screen is blanked. Minor scale fluctuations no longer wake the
display or prevent blanking. The daemon only re-blanks screens it woke
itself — touch-based wake/blank stays with swayidle so the two don't
conflict. Daemon discovers the Wayland session from the shared runtime
dir since it runs as a systemd service outside the compositor.
Swipe down from the top of the SpoolBuddy display to open a quick-access
menu for toggling printer smart plugs and managing the device (restart
daemon, restart browser, reboot, shutdown). All destructive actions
require confirmation.
Backend: new POST /spoolbuddy/devices/{id}/system/command endpoint
queuing reboot/shutdown/restart_daemon/restart_browser commands.
Daemon: handles commands via subprocess (sudo reboot, systemctl restart).
Frontend: SpoolBuddyQuickMenu component, swipe-down gesture detection,
i18n keys for all 7 locales.
The daemon now collects CPU temp, core count, load average, memory/disk
usage, OS info, and system uptime every heartbeat using stdlib-only reads
from /proc and /sys. Stats are sent as a JSON blob in the heartbeat
payload, stored in a new system_stats TEXT column, and displayed in a
new "System" tab in SpoolBuddy Settings with color-coded usage bars.
Temporary diagnostics to identify which step of the NTAG write
fails: per-page ACK status, reactivation, read-back, or data
mismatch. Enable DEBUG level for pn5180 module.
NTAG 213/215/216 chips can report SAK 0x04 (MIFARE Ultralight family)
instead of 0x00 during anticollision. Accept both values for NTAG
detection and write operations in nfc_reader.py and main.py.
The NAU7802 ADC returns a stale max-scale value (0x7FFFFF) on its
first conversion after power-up, polluting the moving average and
making the initial weight report wildly inaccurate. Flush the first
reading during init().
Also extract both hardware drivers out of diagnostic scripts into
proper daemon modules:
- NAU7802 scale driver: scripts/scale_diag.py -> daemon/nau7802.py
- PN5180 NFC driver: scripts/read_tag.py -> daemon/pn5180.py
The production daemon was importing driver classes from test scripts
since the original SpoolBuddy commit. Diagnostic scripts now import
from the driver modules. Removed the sys.path hack from main.py.
The daemon's self-update mechanism (git fetch/reset on its own code) was
fragile: .git permission errors, self-modifying code mid-run, hardcoded
main branch. Bambuddy now SSHes into the SpoolBuddy Pi and drives the
update remotely — matching its own branch, with step-by-step progress
via WebSocket.
SSH key pairing is automatic: Bambuddy generates an ED25519 keypair and
returns the public key in the registration response. The daemon deploys
it to authorized_keys on first connect — no manual setup needed.
- New: backend/app/services/spoolbuddy_ssh.py (keypair, SSH commands, update orchestration)
- Rewritten: trigger_daemon_update endpoint uses SSH instead of pending_command
- New: GET /spoolbuddy/ssh/public-key endpoint for manual pairing
- Removed: daemon _perform_update() and cmd=="update" heartbeat handler
- Updated: install.sh — bash shell, sudoers for systemctl restart, .ssh/ setup
- Updated: Dockerfile — added openssh-client
- Updated: frontend — SSH key display, force update button
- Fixed: update check now compares against APP_VERSION, not GitHub releases
The daemon's self-update mechanism (git fetch/reset on its own code) was
fragile: .git permission errors, self-modifying code mid-run, hardcoded
main branch. Bambuddy now SSHes into the SpoolBuddy Pi and drives the
update remotely — matching its own branch, with step-by-step progress
via WebSocket. Install script updated with SSH access, sudoers entry,
and --ssh-pubkey flag for pairing.
SpoolBuddy devices can now be updated from Settings → Updates without
SSH access. The daemon picks up an "update" command via its existing
heartbeat, runs git fetch/reset + pip install, reports progress back
to the backend, then exits for systemd to restart with the new code.
Backend: update_status/update_message fields, trigger + status endpoints
Daemon: _perform_update() handler, report_update_status() API method
Frontend: "Apply Update" button with live progress in UpdatesTab
Write NTAG213/215/216 tags for third-party spools via the SpoolBuddy
kiosk UI. New "Write" page with three workflows: existing spool, new
spool creation, and tag replacement. Backend encodes 133-byte OpenTag3D
NDEF payloads (material, color, brand, weight, temp). Daemon writes
page-by-page via PN5180 NTAG WRITE command with read-back verification.
Write commands flow through heartbeat polling with WebSocket status
updates. Includes 39 new tests and translations for all 6 languages.
The tare and calibrate buttons on the Settings page queued commands
but never executed them due to three broken links:
1. Daemon received tare command via heartbeat but never called
scale.tare() — the ScaleReader was available in shared dict
but unused
2. No API endpoint for the daemon to report the new tare offset
back to the backend DB, so tare results were lost
3. Heartbeat updated config but never called
scale.update_calibration(), so ScaleReader kept initial values
Added set-tare endpoint + API client method, and fixed heartbeat
loop to execute tare, persist the result, and propagate calibration
changes to the ScaleReader instance. Skip calibration sync on the
heartbeat cycle that delivers a tare command, since the response
predates the tare and would overwrite it with stale values.
The tare and calibrate buttons on the Settings page queued commands
but never executed them due to three broken links:
1. Daemon received tare command via heartbeat but never called
scale.tare() — the ScaleReader was available in shared dict
but unused
2. No API endpoint for the daemon to report the new tare offset
back to the backend DB, so tare results were lost
3. Heartbeat updated config but never called
scale.update_calibration(), so ScaleReader kept initial values
Added set-tare endpoint + API client method, and fixed heartbeat
loop to execute tare, persist the result, and propagate calibration
changes to the ScaleReader instance.
Frontend: Replace inline SpoolInfoCard/UnknownTagCard with full-screen
TagDetectedModal that auto-opens on NFC tag detection. Known spools show
remaining weight, fill bar, and offer "Assign to AMS" (new sub-modal with
printer selector + AMS slot grid) and "Sync Weight". Unknown tags offer
"Add to Inventory" and "Link to Spool". Modal stays open on tag removal,
won't re-open for dismissed tags, reopens on re-place after removal.
Daemon: Fix PN5180 NFC reader silently stopping tag detection when the
reader drifts into a stuck state. Add auto-recovery (full hardware reset
after 10 consecutive errors), preventive RF cycling every 60s when idle,
and periodic status logging. Heartbeat now reports actual nfc_ok/scale_ok
from reader instances instead of hardcoded True.
When ADC noise kept the spread hovering around the 2g stability
threshold, the stable flag toggled every cycle, forcing a report with
a slightly different weight each time. Now only actual weight changes
of >=2g trigger reports. The stable flag is still included in each
report for consumers that need it.
The daemon imports read_tag and scale_diag as bare modules, but they
live in spoolbuddy/scripts/ which isn't on sys.path when systemd runs
the daemon. Added scripts/ to sys.path at startup, resolved relative
to the module file. Also moved the read_tag import inside NFCReader's
try/except (was crashing the daemon instead of skipping gracefully)
and demoted hardware-not-available messages from ERROR to INFO.
SpoolBuddy turns a Raspberry Pi 4B with a PN5180 NFC reader and
NAU7802 scale into a filament management station that integrates
with Bambuddy via REST API and WebSocket.
Backend: SpoolBuddyDevice model, 10 REST endpoints (/spoolbuddy/*),
6 WebSocket broadcast types, background offline-detection watchdog.
RPi daemon: asyncio service with concurrent NFC polling (300ms,
MIFARE Classic + Bambu HKDF key derivation), scale reading (10 SPS,
5-sample moving average, stability detection), and 10s heartbeat
with exponential backoff reconnect.
Frontend: kiosk-optimized 1024x600 UI at /spoolbuddy with Dashboard
(live weight + NFC spool detection), AMS Overview, Inventory,
Printers, and Settings pages. useSpoolBuddyState reducer hook
driven by WebSocket CustomEvents.
i18n: all 6 locales (en, de, fr, it, ja, pt-BR).
maziggy