Picking a new "Screen Blank Timeout" in SpoolBuddy Settings → Display
didn't change actual blanking behaviour: whatever value was active when
the kiosk last booted continued to fire. A user who started with the
10m preset and switched to 1m or "Off" still saw the screen blank at 10m.
Cause: blanking is driven by swayidle, started once by spoolbuddy-idle.sh
at labwc autostart with the timeout passed as a command-line argument.
The script fetched blank_timeout from the backend exactly once at startup
and swayidle has no runtime control surface for changing its timeout.
The daemon's display.set_blank_timeout() updated an in-memory variable
that was never reached by swayidle, so UI changes were silently discarded
until the next kiosk restart.
Fix: extend the wake FIFO protocol with a "reload-timeout N" message.
The daemon writes it whenever set_blank_timeout() sees a value that
differs from the current one (the very first call is suppressed because
the watchdog already fetched the same value at its own startup —
signalling there would just thrash swayidle on every cold boot). The
script's FIFO loop is restructured around start_swayidle / stop_swayidle
helpers and a case statement: wake → wlopm --on + arm a re-blank at the
current timeout; reload-timeout N → kill running swayidle, set TIMEOUT=N,
restart swayidle, wlopm --on so the user sees the change took effect
even if the screen was already blanked. The script de-dupes too — a
reload-timeout whose N matches the current value is a no-op. Going from
any positive timeout to 0 ("Off") stops swayidle and doesn't restart
it; going from 0 to a positive value starts a fresh swayidle. Both work
without a kiosk restart.
The script's main loop opens the FIFO read+write (exec 3<>"$WAKE_FIFO")
so bash read never sees EOF when the daemon momentarily disconnects
between writes. A cleanup trap on TERM/INT/HUP stops swayidle, removes
the FIFO, and exits cleanly.
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.
Display now powers on via wlopm when the daemon detects an NFC tag or
weight change while the screen is blanked. 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.
Display now powers on via wlopm when the daemon detects an NFC tag or
weight change while the screen is blanked. Daemon discovers the Wayland
session from the shared runtime dir and coexists with swayidle which
continues to handle touch-based wake independently.
1. Device tab — repo URL unlinked
Replaced the <a> tag with a <span> so the GitHub URL is displayed as plain text (no clickable link in kiosk mode).
2. Display controls — moved to frontend
Root cause: The daemon runs as a system user without Wayland access, and the kiosk uses an HDMI display (no sysfs backlight). Neither wlopm, vcgencmd, nor sysfs writes
can work in this setup.
Fix — frontend-controlled display in SpoolBuddyLayout.tsx:
- Brightness: CSS filter: brightness(X) applied to the layout root. Immediate visual dimming that works on any display type.
- Screen blanking: Full-screen black overlay (z-[9999]) shown after the configured inactivity timeout. Touch anywhere to wake.
- Activity tracking: Resets on pointerdown/keydown events AND on WebSocket-driven NFC/scale changes (weight update, tag scan).
- Queries device data every 15s to read the current brightness and blank timeout values.
Daemon display_control.py — Simplified:
- Removed vcgencmd/wlopm/subprocess usage entirely
- _blank/_unblank are now state-tracking no-ops (log only)
- DSI backlight brightness via sysfs is preserved as a bonus for DSI displays
- Updated docstring to explain the architecture
3. Scale tab — redesigned with step indicator
Idle state: Same as before — weight card with tare/calibrate buttons.
Calibration wizard: Two-column layout:
- Left column (~64px): Vertical step indicator with numbered circles, checkmark for completed steps, and a connecting line
- Right column: Live weight bar (with stable/settling indicator), step-specific content (instructions or numpad), and action buttons pinned to bottom via mt-auto
The numpad buttons are min-h-[52px] with text-lg — large enough for touch on 1024x600. The weight info card is hidden during the weight entry step to maximize vertical
space.
Root cause: The daemon used wlopm for screen blanking, but wlopm was never installed. Additionally, the daemon runs as the spoolbuddy system user which has no access to
the Wayland socket, so Wayland-based tools can't work.
Fix in display_control.py:
- Replaced wlopm --off/--on with vcgencmd display_power 0/1 — this is a Raspberry Pi firmware-level command that's pre-installed and works without Wayland socket access
- Added shutil.which("vcgencmd") check at init to avoid repeated failures on non-RPi hardware
- Added explicit PermissionError handling for brightness writes with a helpful message about the video group
Fix in install.sh:
- Added video group to the spoolbuddy service user's groups (was: gpio, spi, i2c → now: gpio, spi, i2c, video), which grants access to both vcgencmd and sysfs backlight
files
Scale Tab Numpad
Root cause: On the 1024x600 kiosk screen (~376px available content height), the weight info card + numpad + action buttons exceeded the space, causing tiny buttons and
overlapping.
Fix in SpoolBuddySettingsPage.tsx:
- Hide the weight info card during weight entry step (calStep !== 'weight'), reclaiming ~70px
- Compact inline weight reading in the step header (small dot + monospace text) so users can still see the live scale value
- Larger numpad buttons: min-h-[56px] with text-lg font size (was no min-height, text-sm)
- Added active:scale-95 for tactile touch feedback
- mt-auto on action buttons to push them to the bottom, preventing overlap
- Removed the wrapping card around the calibration flow to save vertical padding
maziggy