fix(web): reject true and 5.5 for row_address_type and multiplexing

Both still went straight through int(), so a JSON true saved as 1 and 5.5
as 5. They now use the shared hardware range check like the other panel
fields. Review feedback on #586.

Also: the RP1 Backend tooltip said it is ignored on Pi 3/4 (it is ignored
on every model but the Pi 5), and the README gave the dynamic-duration
default cap as 90s; the code default is 180s.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

CHANGELOG.md

@@ -19,6 +19,57 @@ accepts both, but the store flags the old spelling as deprecated
 
 ## Unreleased
 
+New module a plugin may import via `src.*` (floor on the release that ships
+this):
+
+- `src/common/sports_helpers.py` — the helpers the scoreboards' `sports.py`
+  carry byte-identical copies of: `clamp_window`, `clamp_seconds`,
+  `logo_needs_refresh`, `spread_weighted_order` (+ `MIN_WINDOW_DAYS`,
+  `MAX_WINDOW_DAYS`), and `SportsHelpersMixin` with `_mode_customization`,
+  `_setting_int`, `_reset_dwell_on_reentry`, `_next_switch_index`,
+  `_spread_weighted_order`, `_odds_color`, `_upcoming_date_and_time_text` under
+  the plugins' names and signatures, plus the `_favorite_key` override point.
+  Constructor-free; keeps lazy state on its host (see the module docstring,
+  which also gives the host contract).
+  A new module rather than more methods on `sports_shared`: a plugin that
+  deletes a copy and leans on an older module having grown the method fails at
+  runtime with `AttributeError`, which no load-time check sees, while a missing
+  module fails at load. Nothing in core uses it yet.
+- `test/test_common_is_hardware_free.py` — `src/common` must import without
+  `rgbmatrix` and never import `src.base_classes`, `src.display_manager` or
+  `src.plugin_system` at module level.
+
+Web interface:
+
+- The plugin settings form honours `"x-display": "hidden"` in config schemas:
+  the property gets no control at any depth (top level, nested objects, array
+  rows, Advanced Settings), and saving the form never changes its stored value.
+  JSON API saves are unaffected. Lets plugins keep deprecated or internal keys
+  declared, e.g. countdown's row `id` and weather's `api_key` / `radar_zoom`.
+  See `docs/widget-guide.md`.
+- Display settings no longer silently cut values on save: columns were capped
+  at 128, chain length at 24 and PWM LSB nanoseconds at 500. Rows, columns and
+  chain length now have no upper limit (the current rgbmatrix library still
+  rejects more than 64 rows per panel); rows must be even and at least 8,
+  parallel is 1–3 and PWM dither bits 0–2, matching the library. A stored GPIO
+  slowdown, PWM dither bits or refresh-rate cap of 0 no longer shows (and
+  re-saves) as 3, 1 or 120, and the refresh cap accepts 0 (no cap). The config
+  API rejects out-of-range or non-integer `rows`, `cols`, `chain_length`,
+  `parallel`, `brightness`, `scan_mode`, `pwm_bits`, `pwm_dither_bits`,
+  `pwm_lsb_nanoseconds`, `limit_refresh_rate_hz`, `row_address_type`,
+  `multiplexing` and `gpio_slowdown` with a 400 (JSON `true` or `5.5` used to
+  save as 1 or 5) instead of saving a config the matrix refuses to start with.
+- Display setting help tips and README / config-reference entries corrected
+  and completed: `panel_type` and `rp1_rio` are documented,
+  `show_refresh_rate` prints to the console rather than drawing on the panel,
+  PWM dither bits raise the refresh rate rather than lowering it, and every
+  numeric setting states its range.
+- Row Address Type offers 5, the SM5368 / B707 row shift register. The
+  Waveshare 96x48 V2 panel (back silkscreen `24S-A1`) needs it with RGB
+  sequence BGR and, on a Pi 4, a GPIO slowdown of 6–8. Panels with FM6124
+  column drivers need no Panel Type. On a Pi 5 the library supports only row
+  address types 0 and 2.
+
 ## 3.4.0
 
 Plugin-facing changes since 3.3.0 (tag `v3.3.1`) not covered further down:

README.md

@@ -494,15 +494,20 @@ These settings control the physical hardware configuration and how the matrix is
 - **`rows`** (integer, default: 32)
   - Number of LED rows (vertical pixels) in each panel
   - Common values: 16, 32, 48, 64
+  - Must be an even number, at least 8. LEDMatrix sets no upper limit, but the
+    current rgbmatrix library rejects more than 64 rows per panel — the display
+    then won't start (see Troubleshooting Display Settings below)
   - Must match your physical panel configuration
 
 - **`cols`** (integer, default: 64)
   - Number of LED columns (horizontal pixels) in each panel
   - Common values: 32, 64, 96, 128
+  - At least 16, with no upper limit
   - Must match your physical panel configuration
 
 - **`chain_length`** (integer, default: 2)
   - Number of LED panels chained together horizontally
+  - At least 1, with no upper limit; longer chains lower the refresh rate
   - If you have 2 panels side-by-side, set to 2
   - If you have 4 panels in a row, set to 4
   - Total display width = `cols × chain_length`
@@ -511,13 +516,14 @@ These settings control the physical hardware configuration and how the matrix is
   - Number of parallel chains (panels stacked vertically)
   - Use 1 for a single row of panels
   - Use 2 if you have panels stacked in two rows
+  - 1–3 on a Raspberry Pi, and the HAT needs that many outputs
   - Total display height = `rows × parallel`
 
 #### Brightness and Visual Settings
 
-- **`brightness`** (integer, 0-100, default: 90)
+- **`brightness`** (integer, 1-100, default: 90)
   - Display brightness level
-  - Lower values (0-50) are dimmer, higher values (50-100) are brighter
+  - Lower values (1-50) are dimmer, higher values (50-100) are brighter
   - Recommended: 70-90 for indoor use, 90-100 for bright environments
   - Very high brightness may cause distortion or require more power
 
@@ -527,52 +533,52 @@ These settings control the physical hardware configuration and how the matrix is
   - Specifies which GPIO pin mapping to use for your hardware
   - **`"adafruit-hat-pwm"`**: Use this for Adafruit RGB Matrix Bonnet/HAT WITH the jumper mod (PWM enabled). This is the recommended setting for Adafruit hardware with the PWM jumper soldered.
   - **`"adafruit-hat"`**: Use this for Adafruit RGB Matrix Bonnet/HAT WITHOUT the jumper mod (no PWM). Remove `-pwm` from the value if you did not solder the jumper.
-  - **`"regular"`**: Standard GPIO pin mapping for direct GPIO connections (Generic)
+  - **`"regular"`**: Standard GPIO pin mapping for direct GPIO connections (Generic). Also the right choice for the Adafruit Triple LED Matrix Bonnet
   - **`"regular-pi1"`**: Standard GPIO pin mapping for Raspberry Pi 1 (older hardware or non-standard hat mapping)
   - Choose the option that matches your specific hardware setup, if aren't sure try them all.
+  - Hardware pulsing (see `disable_hardware_pulsing`) needs the panel's OE line on GPIO 18, which `adafruit-hat-pwm` and `regular` provide and `adafruit-hat` does not
 
 #### PWM (Pulse Width Modulation) Settings
 
 These settings affect color fidelity and smoothness of color transitions:
 
-- **`pwm_bits`** (integer, default: 9)
+- **`pwm_bits`** (integer, 1-11, default: 9)
-  - Number of bits used for PWM (affects color depth)
+  - Color depth per channel: how many brightness levels each LED gets
-  - Higher values (9-11) = more color levels, smoother gradients
+  - Higher values (9-11) = more color levels, smoother gradients, lower refresh rate
-  - Lower values (7-8) = fewer color levels, but may improve stability on some hardware
+  - Lower values (7-8) = the subtlest shades are dropped for a higher refresh rate; `1` gives 8 colors
-  - Range: 1-11, recommended: 9-10
+  - Recommended: 9-10
 
-- **`pwm_dither_bits`** (integer, default: 1)
+- **`pwm_dither_bits`** (integer, 0-2, default: 1)
-  - Additional dithering bits for smoother color transitions
+  - Time-dithers the lowest color bits: their brightness comes from showing them on only some frames
-  - Helps reduce color banding in gradients
+  - Raises the refresh rate; the cost is that dark shades can shimmer slightly
-  - Higher values (1-2) = smoother gradients but may impact performance
+  - `0` = steadiest dim colors, `2` = fastest
-  - Range: 0-2, recommended: 1
+  - The rgbmatrix library accepts only 0-2; a higher value stops the display starting
 
-- **`pwm_lsb_nanoseconds`** (integer, default: 130)
+- **`pwm_lsb_nanoseconds`** (integer, 50-3000, default: 130)
-  - Least significant bit timing in nanoseconds
+  - On-time of the least significant color bit; each higher bit doubles it
-  - Controls the base timing for PWM signals
+  - Lower values = higher refresh rate, but can cost color accuracy or add ghosting on some panels
-  - Lower values = faster PWM, higher values = slower PWM
+  - Higher values = less ghosting (faint trails behind bright text on black), lower refresh rate
   - Typical range: 100-300 nanoseconds
-  - May need adjustment if you see flickering or color issues
 
 #### Advanced Hardware Settings
 
-- **`scan_mode`** (integer, default: 0)
+- **`scan_mode`** (integer, 0-1, default: 0)
-  - Panel scan mode (how rows are addressed)
+  - Order the rows are refreshed in: `0` = progressive, `1` = interlaced
-  - Common values: 0 (progressive), 1 (interlaced)
+  - Interlaced can look a little smoother when the refresh rate is very low, but usually shows a comb effect on anything moving
-  - Most panels use 0, but some require 1
+  - Leave at `0` unless you are tuning a slow setup
-  - Check your panel datasheet if colors appear incorrect
 
 - **`limit_refresh_rate_hz`** (integer, default: 100)
-  - Maximum refresh rate in Hz (frames per second)
+  - Caps the panel refresh rate in Hz; `0` = no cap
-  - Caps the refresh rate for better stability
+  - A steady cap reduces flicker caused by other activity on the Pi, and in camera recordings
-  - Lower values (60-80) = more stable, less CPU usage
+  - Scroll speeds are worked out against this value (against 100 Hz when it is `0`), so a cap the panel can actually hold keeps scrolling even
-  - Higher values (100-120) = smoother animations, more CPU usage
+  - If the key is missing from the config, `DisplayManager` uses 90
-  - Recommended: 80-100 for most setups
+  - Recommended: 80-120. `sudo python3 scripts/scroll_speeds.py --measure` reports the rate your panel really achieves
 
 - **`disable_hardware_pulsing`** (boolean, default: false)
-  - Disables hardware pulsing (usually leave as false)
+  - `false` = the Pi's hardware PWM times each brightness pulse; `true` = software timing
-  - Set to `true` only if you experience timing issues
+  - Leave `false` where possible. Software timing is less exact, so a row, or the whole panel, can briefly flash brighter
-  - Most users should leave this as `false`
+  - Hardware pulsing needs the panel's OE line on GPIO 18 (`adafruit-hat-pwm`, `regular`, the Adafruit Triple LED Matrix Bonnet). With `adafruit-hat` the library uses software timing anyway
+  - It also needs the Pi's onboard sound driver (`snd_bcm2835`) disabled, which `first_time_install.sh` does. Set `true` only if you need the Pi's own audio
 
 - **`inverse_colors`** (boolean, default: false)
   - Inverts all colors (red becomes cyan, etc.)
@@ -580,9 +586,9 @@ These settings affect color fidelity and smoothness of color transitions:
   - Set to `true` only if colors appear inverted
 
 - **`show_refresh_rate`** (boolean, default: false)
-  - Displays the current refresh rate on the matrix (for debugging)
+  - Prints the live refresh rate to the console; nothing is drawn on the panel
-  - Set to `true` to see FPS on the display
+  - Readable when you stop the service and run `sudo python3 run.py` in a terminal; under the service the output is buffered
-  - Useful for troubleshooting performance issues
+  - `sudo python3 scripts/scroll_speeds.py --measure` is an easier way to see the real refresh rate
 
 #### Advanced Panel Configuration (Advanced Users Only)
 
@@ -592,6 +598,7 @@ These settings are typically only needed for non-standard panels or custom confi
   - Color channel order for your LED panel
   - Common values: "RGB", "RBG", "GRB", "GBR", "BRG", "BGR"
   - Most panels use "RGB", but some use "GRB" or other orders
+  - If red shows as blue, try "BGR" (the Waveshare 96x48 V2 needs it)
   - Check your panel datasheet if colors appear wrong
 
 - **`pixel_mapper_config`** (string, default: "")
@@ -612,29 +619,56 @@ These settings are typically only needed for non-standard panels or custom confi
 - **`row_address_type`** (integer, default: 0)
   - How rows are addressed on the panel
   - Most panels use 0 (direct addressing)
-  - Some panels require 1 (AB addressing) or 2 (ABC addressing)
+  - 1 = AB-addressed, 2 = direct row select, 3 = ABC-addressed,
+    4 = ABC shift + DE direct (SM5266), 5 = SM5368 / B707 row shift register
+  - ABC panels (no E line, e.g. many 128x64 FM6124 panels) use 3
+  - Panels with SM5368 row drivers use 5 with `led_rgb_sequence` `"BGR"` —
+    e.g. the Waveshare 96x48 V2 (back silkscreen `24S-A1`; the V1, `24S-A2.1`,
+    uses the defaults). This is what Waveshare's `96X48_1_24_SM5368` panel
+    type sets in their library fork.
+  - SM5368 row drivers are timing-sensitive: if rows jump up and down or the
+    bottom row shows a copy of other rows, raise `gpio_slowdown`. On a Pi 4
+    with an Adafruit Triple LED Matrix Bonnet, 4 left rows jumping; 6–8 gave a
+    stable image.
+  - On a Raspberry Pi 5 the rgbmatrix library currently supports only 0 and 2
   - Check your panel datasheet if display appears corrupted
 
-- **`multiplexing`** (integer, default: 0)
+- **`multiplexing`** (integer, 0-22, default: 0)
-  - Panel multiplexing type
+  - How pixels are wired on outdoor/specialty panels (P10, P8, P4 and P3 outdoor modules and similar) whose LEDs aren't laid out in straight rows
-  - 0 = no multiplexing (standard panels)
+  - `0` = direct (standard indoor panels)
-  - Higher values for panels with different multiplexing schemes
+  - `1` Stripe, `2` Checkered, `3` Spiral, `4` ZStripe, `5` ZnMirrorZStripe,
-  - Check your panel datasheet for the correct value
+    `6` Coreman, `7` Kaler2Scan, `8` ZStripeUneven, `9` P10-128x4-Z,
+    `10` QiangLiQ8, `11` InversedZStripe, `12`–`14` P10Outdoor1R1G1B v1–v3,
+    `15` P10CoremanMapper, `16` P8Outdoor1R1G1B, `17` FlippedStripe,
+    `18` P10-32x16-HalfScan, `19` P10-32x16-QuarterScan, `20` P3Outdoor-64x64,
+    `21` DoubleZMultiplex, `22` P4Outdoor-80x40
+  - If the image is scrambled in a repeating pattern, try the value named after your panel first
+
+- **`panel_type`** (string, default: `""`)
+  - Sends a start-up initialization sequence to driver chips that need one
+  - `""` = Standard (no initialization) — right for most panels, including FM6124 / FM6124D / FM6124DJ
+  - `"FM6126A"` or `"FM6127"` for panels with those chips; try `"FM6126A"` if the panel stays dark or lights only the first pixel on Standard
 
 ### Runtime Configuration (`display.runtime`)
 
 These settings control runtime behavior and GPIO timing:
 
 - **`gpio_slowdown`** (integer, default: 3)
-  - GPIO timing slowdown factor
+  - GPIO timing slowdown factor (0-10): slows GPIO writes so the panel electronics keep up. Higher is more reliable but lowers the refresh rate
-  - **Critical setting**: Must match your Raspberry Pi model for stability
+  - **Critical setting**: depends on your Raspberry Pi model and your panel
-  - **Raspberry Pi 3**: Use 3
+  - **Raspberry Pi Zero/1**: 0-1
-  - **Raspberry Pi 4**: Use 4
+  - **Raspberry Pi 2/3**: 1-3
-  - **Raspberry Pi 5**: Use 1–2 in PIO mode (`rp1_rio: 0`, the default); start with `1` and increase if you see flickering
+  - **Raspberry Pi 4**: 2-4 (the config template ships 3)
-  - **Raspberry Pi Zero/1**: Use 1-2
+  - **Raspberry Pi 5**: 1–3 in PIO mode (`rp1_rio: 0`, the default); start with `1` and increase if you see flickering
-  - Incorrect values can cause display corruption, flickering, or system instability
+  - Panels on `row_address_type` 5 (SM5368 row drivers) can need 6-8 on a Pi 4
+  - Too low: garbage, flicker or rows jumping. Too high: a lower refresh rate
   - If you experience issues, try adjusting this value up or down by 1
 
+- **`rp1_rio`** (integer, 0 or 1, default: 0) — Raspberry Pi 5 only
+  - Which driver the Pi 5's RP1 chip uses: `0` = PIO (default, less CPU), `1` = RIO (registered I/O, can reach a higher refresh rate)
+  - In RIO mode the effect of `gpio_slowdown` is inverted: higher values may be faster
+  - Ignored on a Pi 0-4, and applied only if the installed rgbmatrix library supports it
+
 ### Display Durations (`display.display_durations`)
 
 Controls how long each installed plugin stays visible in seconds before switching to the next one, keyed by plugin id.
@@ -667,7 +701,7 @@ Controls how long each installed plugin stays visible in seconds before switchin
   - Some plugins can automatically adjust their display time based on content
   - This setting limits how long they can extend (prevents one display from dominating)
   - Example: If set to 60, a plugin can extend up to 60 seconds even if it requests longer
-  - Leave unset to use the default cap (typically 90 seconds)
+  - Leave unset to use the default cap (180 seconds; the web UI accepts 30-1800)
 
 ### Example Configuration
 
@@ -714,6 +748,14 @@ Controls how long each installed plugin stays visible in seconds before switchin
 - Verify `hardware_mapping` matches your HAT/connection type
 - Try adjusting `gpio_slowdown`
 - Ensure your display doesn't need the E-Addressable line
+- If it went blank right after a settings change, check `sudo journalctl -u ledmatrix` for `Failed to initialize RGB Matrix`: the rgbmatrix library refused a value (for example more than 64 `rows`, or `pwm_dither_bits` above 2) and the display fell back to no output. The library's own message nearby names the setting
+- A repeating scramble points at `row_address_type` or `multiplexing`; a panel that stays dark, at `panel_type`
+
+**Rows jump up and down, or the bottom row repeats other rows:**
+- Raise `gpio_slowdown` a step at a time (SM5368 panels on `row_address_type` 5 can need 6-8 on a Pi 4)
+
+**A row or the whole panel briefly flashes brighter:**
+- Set `disable_hardware_pulsing` to `false` (needs the OE line on GPIO 18; see `hardware_mapping`)
 
 **Colors are wrong or inverted:**
 - Check `led_rgb_sequence` (try "GRB" if "RGB" doesn't work)

docs/CONFIG_REFERENCE.md

@@ -51,25 +51,25 @@ in `DisplayManager` (`src/display_manager.py`, ~lines 270–295).
 
 | Key | Type / default |
 |---|---|
-| `rows` / `cols` | int, `32` / `64` |
+| `rows` / `cols` | int, `32` / `64` — rows: even, at least 8, no upper limit here (the current rgbmatrix library rejects more than 64); cols: at least 16, no upper limit |
-| `chain_length` | int, `2` |
+| `chain_length` | int, `2` — at least 1, no upper limit |
-| `parallel` | int, `1` |
+| `parallel` | int, `1` — 1–3 |
-| `brightness` | int, `90` |
+| `brightness` | int, `90` — 1–100 |
 | `hardware_mapping` | string, `"adafruit-hat"` (code default `"adafruit-hat-pwm"`) |
-| `scan_mode` | int, `0` |
+| `scan_mode` | int, `0` — `0` progressive, `1` interlaced |
-| `pwm_bits` | int, `9` (code default 10) |
+| `pwm_bits` | int, `9` (code default 10) — 1–11 |
-| `pwm_dither_bits` | int, `1` |
+| `pwm_dither_bits` | int, `1` — 0–2 |
-| `pwm_lsb_nanoseconds` | int, `130` (code default 150) |
+| `pwm_lsb_nanoseconds` | int, `130` (code default 150) — 50–3000 |
-| `disable_hardware_pulsing` | bool, `false` |
+| `disable_hardware_pulsing` | bool, `false` — `true` times brightness pulses in software (less exact); hardware pulsing needs the OE line on GPIO 18 and the Pi's onboard sound driver off |
 | `inverse_colors` | bool, `false` |
-| `show_refresh_rate` | bool, `false` |
+| `show_refresh_rate` | bool, `false` — prints the refresh rate to stdout; draws nothing on the panel |
-| `led_rgb_sequence` | string, `"RGB"` |
+| `led_rgb_sequence` | string, `"RGB"` — `"RGB"`, `"RBG"`, `"GRB"`, `"GBR"`, `"BRG"` or `"BGR"` |
-| `limit_refresh_rate_hz` | int, `100` (code default 90) |
+| `limit_refresh_rate_hz` | int, `100` (code default 90) — `0` = no cap; scroll timing assumes 100 Hz when `0` |
 | `pixel_mapper_config` | string, `""` — e.g. `"U-mapper"` / `"Rotate:90"` |
 | `orientation` | string, `"normal"` — `"180"` rotates the rendered image 180° for panels physically mounted upside down (e.g. to move the Pi/wiring to a more convenient side); composed onto `pixel_mapper_config` as a trailing `Rotate:180` mapper, so it stays independent of any custom `pixel_mapper_config` value |
-| `row_address_type` | int, `0` — non-standard panel row addressing |
+| `row_address_type` | int, `0` — non-standard panel row addressing: `1` AB, `2` direct row select, `3` ABC, `4` ABC shift + DE direct, `5` SM5368 / B707 row shift register (e.g. Waveshare 96x48 V2, with `led_rgb_sequence` `"BGR"`). On a Pi 5 the library supports only `0` and `2` |
-| `multiplexing` | int, `0` — panel multiplexing scheme |
+| `multiplexing` | int, `0` — 0–22, pixel wiring scheme for outdoor/specialty panels (names listed in the README) |
-| `panel_type` | string, `""` — set to `"FM6126A"` or `"FM6127"` for panels needing init |
+| `panel_type` | string, `""` — set to `"FM6126A"` or `"FM6127"` for panels needing init; FM6124 / FM6124D / FM6124DJ panels need none, so leave it `""` |
 
 Where "code default" differs from the template value, the code default only
 applies if the key is missing entirely from your config.
@@ -78,8 +78,8 @@ applies if the key is missing entirely from your config.
 
 | Key | Type / default | Meaning |
 |---|---|---|
-| `gpio_slowdown` | int, `3` | GPIO timing slowdown for faster Pis |
+| `gpio_slowdown` | int, `3` | GPIO timing slowdown for faster Pis (0–10). Panels on `row_address_type` `5` (SM5368 row drivers) can need 6–8 on a Pi 4 — lower values make rows jump |
-| `rp1_rio` | int, `0` | RP1 RIO mode on Pi 5 (applied only if the installed matrix library supports it) |
+| `rp1_rio` | int, `0` | Pi 5 only: `0` = PIO (less CPU), `1` = RIO (higher refresh; `gpio_slowdown` effect inverted). Applied only if the installed matrix library supports it |
 
 ## `display.double_sided`
 

docs/GETTING_STARTED.md

@@ -83,10 +83,10 @@ You should see:
 
 1. Open the **Display** tab
 2. Set your matrix configuration:
-   - **Rows**: 32 or 64 (match your hardware)
+   - **Rows**: match your panel — commonly 32 or 64; any even number
-   - **Columns**: commonly 64 or 96; the web UI accepts any integer
+     from 8 to 64
-     in the 1–128 range, but 64 and 96 are the values the bundled
+   - **Columns**: match your panel — commonly 64 or 96; at least 16,
-     panel hardware ships with
+     with no upper limit
    - **Chain Length**: Number of panels chained horizontally
    - **Hardware Mapping**: usually `adafruit-hat-pwm` (with the PWM jumper
      mod) or `adafruit-hat` (without). See the root README for the full list.

docs/SPORTS_UNIFICATION.md

@@ -80,11 +80,30 @@ src/base_classes/sports/
 src/common/
   sports_scroll.py       SportsScrollDisplay / …Manager — scroll orchestration
                          (content building stays in the plugins)
+  sports_helpers.py      clamp/logo/rotation free functions + SportsHelpersMixin
+                         (unreleased) — the helpers byte-identical in the
+                         plugins' sports.py, and the _favorite_key seam
 ```
 
 `from src.base_classes.sports import SportsCore` keeps working — the package
 `__init__` re-exports, so the conversion is invisible to every existing importer.
 
+### Converging on `src/common`
+
+The scoreboards do not build on `src/base_classes`; their own `sports.py` copies
+have moved past it. So shared code now lands in hardware-free `src/common`
+modules taken from the plugin copies, each a **new module** rather than growth
+on an existing one: a plugin that deletes a method copy and relies on an older
+module having gained it fails at runtime with an `AttributeError`, while a
+missing module fails at load, where the version checks can see it.
+`sports_helpers.py` is the first (it holds `_favorite_key`, the override point
+listed below, for later phases); its parity test compares every body against
+the plugin copies when `LEDMATRIX_PLUGINS` points at a checkout, and
+`test/test_common_is_hardware_free.py` keeps `src/common` free of
+`rgbmatrix`, `src.base_classes` and `src.plugin_system`. How a plugin adopts a
+module and drops its copy is documented in the plugins repo's
+`docs/plugin-development/08-shared-sports-code.md`.
+
 ## Override points (the plugin-facing seam)
 
 The base class calls these; plugins implement or override them. This table is the

docs/WEB_INTERFACE_GUIDE.md

@@ -132,18 +132,26 @@ require a display service restart from **Overview**.
 Configure your LED matrix hardware:
 
 **Matrix configuration:**
-- `rows` — LED rows (typically 32 or 64)
+- `rows` — LED rows per panel (typically 32 or 64; even, at least 8 — the
-- `cols` — LED columns (typically 64 or 96)
+  current rgbmatrix library rejects more than 64)
+- `cols` — LED columns per panel (typically 64 or 96; at least 16)
 - `chain_length` — number of horizontally chained panels
-- `parallel` — number of parallel chains
+- `parallel` — number of parallel chains (1–3)
 - `hardware_mapping` — `adafruit-hat-pwm` (with PWM jumper mod),
-  `adafruit-hat` (without), `regular`, or `regular-pi1`
+  `adafruit-hat` (without), `regular` (direct wiring, and the Adafruit Triple
-- `gpio_slowdown` — must match your Pi model (3 for Pi 3, 4 for Pi 4, etc.)
+  LED Matrix Bonnet), or `regular-pi1`
-- `brightness` — 0–100%
+- `gpio_slowdown` — depends on your Pi and panel (roughly 1–3 on a Pi 3,
+  2–4 on a Pi 4); raise it if rows jump or the image is garbage
+- `brightness` — 1–100%
 - `pwm_bits`, `pwm_lsb_nanoseconds`, `pwm_dither_bits` — PWM tuning
 - Dynamic Duration — global cap for plugins that extend their display
   time based on content
 
+The collapsed **Advanced Hardware & Display Options** section holds
+multiplexing, panel type, row address type, scan mode, PWM tuning, the
+refresh-rate cap and hardware pulsing. Every field has a help tip, and the
+README's Display Settings section describes each one with its allowed range.
+
 **Vegas Scroll Mode:** the Display tab also has a full Vegas Scroll
 Mode section — enable toggle, scroll speed, separator width, dynamic
 duration, and related settings — so you can configure Vegas mode

docs/widget-guide.md

@@ -281,6 +281,42 @@ Guidelines:
   their own collapsible sections) and is safely ignored by older cores, so
   adding it never breaks compatibility.
 
+## Hiding Fields From the Form (`x-display: "hidden"`)
+
+Add `"x-display": "hidden"` to a property that must stay in the schema but
+should not appear as a control: a deprecated key kept so existing configs keep
+validating, or an internal value such as an auto-generated row id.
+
+```json
+{
+  "properties": {
+    "radar_zoom": {
+      "type": "integer",
+      "default": 6,
+      "title": "Radar Zoom Level (deprecated)",
+      "x-display": "hidden"
+    }
+  }
+}
+```
+
+What the core does with it:
+
+- **Not rendered** at any depth: top-level fields, children of an object
+  section, and properties of array-of-object items (never a table column, even
+  if `x-columns` names it, and never in the row editor). A hidden field flagged
+  `x-advanced` is not listed or counted in Advanced Settings, and an object
+  whose children are all hidden draws no empty section. Hidden fields don't
+  show up in the settings search either, since it indexes the rendered form.
+- **Stored value preserved on save.** Saving the form never changes a hidden
+  value. The unchecked-checkbox rule ignores a hidden boolean. Array rows carry
+  a hidden property's stored value through the form, so the value survives the
+  row being posted back; a new row gets no value (the plugin fills it in).
+- **The API is unaffected.** A JSON save to `POST /api/v3/plugins/config` can
+  still set a hidden field.
+
+Older cores ignore the flag and render the field as a normal control.
+
 ## Creating Custom Widgets
 
 ### Step 1: Create Widget File

src/common/sports_helpers.py

@@ -0,0 +1,408 @@
+"""Sports helpers every scoreboard's ``sports.py`` carries an identical copy of.
+
+Ten helpers are byte-identical (executable AST, docstrings stripped) in the
+scoreboard plugins' ``sports.py`` and have no equivalent elsewhere in
+``src/common``. The bodies below were copied from those plugin copies -- not
+from ``src/base_classes`` -- at ledmatrix-plugins ``f09bff2`` (origin/main,
+2026-09-14):
+
+- In all nine (afl, baseball, basketball, football, hockey, lacrosse, nrl,
+  soccer, ufc): ``_clamp_window``, ``_clamp_seconds``, ``_logo_needs_refresh``
+  (with ``_MIN_WINDOW_DAYS`` / ``_MAX_WINDOW_DAYS``), and the ``SportsCore``
+  methods ``_mode_customization``, ``_setting_int``,
+  ``_reset_dwell_on_reentry`` (with ``_DWELL_REENTRY_GAP_SECONDS``),
+  ``_next_switch_index`` and ``_spread_weighted_order``.
+- In the eight that share a lineage (all but ufc, which has neither):
+  ``_odds_color`` and ``_upcoming_date_and_time_text``.
+
+The module-level helpers become public free functions here (``clamp_window``,
+``clamp_seconds``, ``logo_needs_refresh``, ``spread_weighted_order``,
+``MIN_WINDOW_DAYS``, ``MAX_WINDOW_DAYS``); the methods keep the plugins' exact
+names and signatures on ``SportsHelpersMixin`` so adopting it is deleting the
+copies and adding one base. ``test/test_sports_helpers.py`` compares every body
+here against every plugin copy when a plugins checkout is available
+(``LEDMATRIX_PLUGINS``), so drift in either direction fails a test.
+
+WHY A NEW MODULE, NOT MORE METHODS ON sports_shared
+---------------------------------------------------
+A plugin that deletes its copy of a method and relies on an *existing* module
+having grown it fails at runtime on an older core: ``AttributeError`` mid-render,
+usually swallowed into a blank board. The plugin loader cannot see that, and
+neither can the plugins' ``scripts/check_min_core_version.py``, which checks
+modules. A plugin importing a module that does not exist yet fails at load,
+where both can. Plugins import this and floor ``ledmatrix_min_version`` on the
+first core release that ships it (see ``CHANGELOG.md``).
+
+``_favorite_key`` is the one method not taken from the plugins: it is the
+override point from ``src/base_classes/sports/core.py``, carried here so later
+phases (shared celebrations and game selection) have a hardware-free home for
+the seam. No plugin defines it today and nothing in this module calls it.
+
+WHAT A HOST MUST PROVIDE
+------------------------
+Derived by walking every ``self.<attr>`` the mixin reads; the host-contract
+test in ``test/test_sports_helpers.py`` fails if a read is added without being
+listed here.
+
+- ``config`` (dict) -- ``_mode_customization``.
+- ``mode_config`` (dict) and ``logger`` -- ``_setting_int``. ``league`` is
+  read with ``getattr`` for the warning text only.
+- ``games_list`` and ``current_game_index`` -- ``_next_switch_index``; plus
+  ``_is_favorite_game`` (called with a game), which stays per-plugin and is
+  only called when
+  ``favorite_rotation_boost`` is above 1. ``favorite_rotation_boost`` itself
+  defaults to 1 on the mixin.
+- ``last_game_switch`` -- ``_reset_dwell_on_reentry``, read with ``getattr``
+  and written back.
+- ``_card_option``, ``_format_game_date`` and ``_format_game_time`` --
+  ``_upcoming_date_and_time_text``. All three are on
+  ``SportsCoreSharedMixin`` (``src/common/sports_shared.py``).
+- ``_element_color`` -- ``_odds_color``, looked up with ``getattr`` and falling
+  back to green, so a host without it still works. Also on
+  ``SportsCoreSharedMixin``.
+- ``SKIN_MODE`` -- optional, read with ``getattr`` by ``_mode_customization``;
+  without it the mode overrides are simply not merged.
+
+State the mixin keeps on the host, created on first use (all read with
+``getattr``, so nothing needs initialising): ``_last_display_call_monotonic``,
+``_switch_order``, ``_switch_order_key``, ``_switch_position``.
+
+Class-level defaults: ``_DWELL_REENTRY_GAP_SECONDS = 5.0`` and
+``favorite_rotation_boost = 1``, matching the plugins. A host's own value
+shadows them.
+
+MRO
+---
+No ``__init__`` and no bare ``super()``, so base order does not change what
+runs. By convention list it after ``SportsCoreSharedMixin``::
+
+    class SportsCore(SportsCoreSharedMixin, SportsHelpersMixin, ABC):
+
+HARDWARE-FREE
+-------------
+Nothing here may import ``src.display_manager``, ``src.base_classes``,
+``src.plugin_system`` or anything else that reaches ``rgbmatrix`` at module
+level; ``test/test_common_is_hardware_free.py`` enforces that for all of
+``src/common``. ``logo_needs_refresh`` imports ``src.logo_downloader`` lazily,
+exactly as the plugin copy does.
+"""
+
+from __future__ import annotations
+
+import time
+from typing import Any, ClassVar, Dict, List, Optional, Tuple
+
+__all__ = [
+    "MIN_WINDOW_DAYS",
+    "MAX_WINDOW_DAYS",
+    "clamp_window",
+    "clamp_seconds",
+    "logo_needs_refresh",
+    "spread_weighted_order",
+    "SportsHelpersMixin",
+]
+
+MIN_WINDOW_DAYS = 1
+MAX_WINDOW_DAYS = 60
+
+
+def clamp_window(value: Any, fallback: int) -> int:
+    """Days for one side of the schedule window, or the default if unusable."""
+    try:
+        days = int(value)
+    except (TypeError, ValueError, OverflowError):
+        # OverflowError: json parses a bare Infinity and int(inf) raises,
+        # which crashed manager init from a hand-edited config.
+        return fallback
+    return max(MIN_WINDOW_DAYS, min(MAX_WINDOW_DAYS, days))
+
+
+def clamp_seconds(value: Any, fallback: int, low: int = 5,
+                  high: int = 86400) -> int:
+    """An interval in seconds, or the fallback when the value is unusable."""
+    try:
+        seconds = int(value)
+    except (TypeError, ValueError, OverflowError):
+        # OverflowError: json parses bare Infinity by default and int(inf)
+        # raises -- the same gap clamp_window above already covers.
+        return fallback
+    return max(low, min(high, seconds))
+
+
+def logo_needs_refresh(logo_file) -> bool:
+    """True if this file is a placeholder stale enough to retry the real logo.
+
+    A failed logo download is cached as a placeholder wearing the real logo's
+    filename, so "the file exists" is not proof the logo was ever fetched.
+    Without this check one transient failure leaves a team a grey box forever.
+
+    Returns False on a core that predates placeholder marking, which keeps the
+    previous behaviour rather than breaking the load.
+    """
+    # Imported from the core by its full path, never as a bare name: a
+    # deferred bare-name import can bind another plugin's vendored
+    # logo_downloader once the core isolates top-level plugin modules.
+    try:
+        from src.logo_downloader import (
+            PLACEHOLDER_RETRY_SECONDS,
+            is_placeholder_logo,
+            placeholder_age_seconds,
+        )
+    except ImportError:
+        return False
+
+    try:
+        if not is_placeholder_logo(logo_file):
+            return False
+        age = placeholder_age_seconds(logo_file)
+        return age is None or age >= PLACEHOLDER_RETRY_SECONDS
+    except Exception:
+        return False
+
+
+def spread_weighted_order(weights: List[int]) -> List[int]:
+    """Indices into ``weights``, each repeated by its weight and spread out.
+
+    Each index keeps its own slot and places its extra turns at even
+    fractions of the rotation after it, wrapping round. That keeps the
+    list's schedule order for everything else and spaces a favourite's
+    repeats evenly *around the loop* -- the live rotation's smooth
+    weighted round-robin schedules a boosted game first and last, so a
+    rotation that wraps shows it back to back. Equal weights come back in
+    plain order, so a boost that applies to no card changes nothing.
+
+    Repeats are kept apart only where the ratio leaves room: once one
+    weight exceeds all the others combined, no cyclic order can separate
+    its turns ([3, 1, 1] gives [0, 1, 0, 2, 0]). Each index still gets
+    exactly its weight in turns -- the configured ratio wins over spacing.
+    """
+    count = len(weights)
+    slots = []
+    for index, weight in enumerate(weights):
+        for turn in range(weight):
+            slots.append(((index + turn * count / weight) % count, turn > 0, index))
+    return [index for _, _, index in sorted(slots)]
+
+
+class SportsHelpersMixin:
+    """The ``SportsCore`` methods identical across the scoreboards' sports.py.
+
+    Constructor-free; keeps lazy state on its host (see the module docstring
+    for that state, the host contract and base-order guidance).
+    """
+
+    #: Longest gap between two display() calls that still counts as one
+    #: on-screen stint. Frames arrive many times a second while a mode is on
+    #: the panel; between mode blocks the gap is the length of every other
+    #: mode's block -- a minute or more. Anything past a few seconds can only
+    #: be a block boundary, or the very first frame after startup.
+    _DWELL_REENTRY_GAP_SECONDS: ClassVar[float] = 5.0
+
+    #: Turns a favourite's card gets per turn of any other card in switch
+    #: mode. The plugins set it per instance from config; this default keeps
+    #: a host that does not on the plain rotation.
+    favorite_rotation_boost: int = 1
+
+    def _favorite_key(self, game: Dict, side: str) -> Optional[str]:
+        """Override point: which view-model field identifies a team when
+        matching against ``favorite_teams``.
+
+        ``side`` is ``"home"`` or ``"away"``. The default is the team
+        abbreviation -- what eight of the nine scoreboards match on, and what
+        users type into their favorites list.
+
+        NRL needs the team **id** instead, because NRL abbreviations are not
+        unique: "NEW" is both Newcastle Knights and New Zealand Warriors,
+        "CAN" both Canberra Raiders and Canterbury Bulldogs. It is a seam
+        rather than a branch so core never has to learn the string "nrl"::
+
+            def _favorite_key(self, game, side):
+                return str(game.get(f"{side}_id"))
+
+        An override that stringifies should note that a missing id becomes the
+        literal ``"None"``, which would spuriously match a favorites list
+        containing that string. The default returns ``None`` for a missing
+        abbreviation, which never matches.
+
+        Carried from ``src/base_classes/sports/core.py`` for later phases;
+        nothing in this module calls it yet.
+        """
+        return game.get(f"{side}_abbr")
+
+    def _mode_customization(self) -> dict:
+        """``customization`` with this mode's overrides merged over it.
+
+        SportsUpcoming / SportsRecent / SportsLive are separate instances
+        with their own SKIN_MODE, so merging once here makes every
+        per-element lookup mode-aware without changing one of them.
+
+        ``None`` in a mode block means "inherit", which is what lets a user
+        restyle one element on live cards and leave everything else
+        following the settings above. It has to stay distinct from 0: a mode
+        y_offset of 0 means "sit at the base position", not "no preference".
+        """
+        customization = self.config.get('customization', {})
+        if not isinstance(customization, dict):
+            return {}
+        mode = getattr(self, 'SKIN_MODE', None)
+        if not mode:
+            return customization
+        modes = customization.get('modes')
+        block = modes.get(mode) if isinstance(modes, dict) else None
+        if not isinstance(block, dict):
+            return customization
+
+        merged = dict(customization)
+        for element, override in block.items():
+            if element == 'layout' or not isinstance(override, dict):
+                continue
+            base = merged.get(element)
+            base = dict(base) if isinstance(base, dict) else {}
+            base.update({k: v for k, v in override.items() if v is not None})
+            merged[element] = base
+
+        mode_layout = block.get('layout')
+        if isinstance(mode_layout, dict):
+            base_layout = merged.get('layout')
+            new_layout = dict(base_layout) if isinstance(base_layout, dict) else {}
+            for element, axes in mode_layout.items():
+                if not isinstance(axes, dict):
+                    continue
+                current = new_layout.get(element)
+                current = dict(current) if isinstance(current, dict) else {}
+                current.update({k: v for k, v in axes.items() if v is not None})
+                new_layout[element] = current
+            merged['layout'] = new_layout
+        return merged
+
+    def _setting_int(self, key: str, default: int, low: int, high: int) -> int:
+        """A count from config, clamped to the range its schema declares.
+
+        The schema constrains these, but config.json can be hand-edited or
+        written by an older tool, and a string or a negative here does not
+        raise where anyone would see it -- it raises inside update()'s own
+        try/except, which shows up as a mode that silently renders nothing.
+        Same shape as the favorite_live_boost clamp in the plugins.
+        """
+        try:
+            return max(low, min(high, int(self.mode_config.get(key, default))))
+        except (TypeError, ValueError, OverflowError):
+            # OverflowError: json parses a bare Infinity, and int(inf) raises
+            # -- from __init__, outside any try/except, so the manager would
+            # fail to construct instead of falling back.
+            self.logger.warning(
+                "%s: ignoring unusable %s=%r, using %s",
+                getattr(self, "league", "?"), key,
+                self.mode_config.get(key), default,
+            )
+            return default
+
+    def _reset_dwell_on_reentry(self) -> bool:
+        """Give the current card a full turn when this mode (re)takes the panel.
+
+        The dwell clock (last_game_switch) keeps running while the mode is off
+        screen, so on re-entry it was always long expired and the first
+        display() call advanced immediately: the card cut off by the end of
+        the previous block was skipped instead of shown -- measured at one in
+        five card transitions on a 30s block of 15s cards -- and after a
+        service restart the clock started at manager construction, seconds
+        before the first frame, shaving that much off the first card. Both are
+        the same defect: the dwell clock counting time the viewer never saw.
+
+        Returns True when the dwell was reset, so the caller forces a redraw.
+        The one-frame card at the end of a block (the advance that races the
+        controller's mode switch) still renders -- this reset is what turns it
+        into the card that opens the next block with a full turn, instead of
+        one the rotation skipped.
+        """
+        # getattr, and zero treated as "never displayed": the managers are
+        # constructed in several places -- the plugin tests among them -- not
+        # all of which set every attribute, and a freshly booted Pi can reach
+        # the first frame while time.monotonic() itself is still under the
+        # gap threshold, which would make `now - 0.0` look like one stint.
+        last = getattr(self, "_last_display_call_monotonic", 0.0)
+        now = time.monotonic()
+        self._last_display_call_monotonic = now
+        if last > 0.0 and now - last < self._DWELL_REENTRY_GAP_SECONDS:
+            return False
+        if getattr(self, "last_game_switch", 0) <= 0:
+            # Zero is the live screen's "no game shown yet" sentinel with its
+            # own handling; overwriting it here would hide the first game's
+            # arrival from that logic.
+            return False
+        self.last_game_switch = time.time()
+        return True
+
+    _spread_weighted_order = staticmethod(spread_weighted_order)
+
+    def _next_switch_index(self) -> int:
+        """The games_list index switch mode shows next.
+
+        favorite_rotation_boost gives a favourite's card that many turns for
+        every one turn another card gets, spread through the rotation and kept
+        apart wherever the other cards leave room (a boost above the number of
+        other cards makes some repeats adjacent; the ratio is kept either way).
+        games_list itself stays one entry per game -- the
+        cycle-duration count, the scroll strip and the other-games re-cut all
+        read it -- so the weighting is an order walked over it instead.
+
+        The order is rebuilt whenever the list's games change, and the walk
+        resyncs from current_game_index whenever the two disagree: update()
+        and the other-games rotation both set the index directly when they
+        swap a list in, and the card on screen is where the walk resumes.
+
+        Called with _games_lock held and games_list non-empty.
+        """
+        count = len(self.games_list)
+        boost = getattr(self, "favorite_rotation_boost", 1)
+        if boost <= 1 or count < 2:
+            return (self.current_game_index + 1) % count
+        key = (boost, tuple(g.get("id") for g in self.games_list))
+        if getattr(self, "_switch_order_key", None) != key:
+            self._switch_order = self._spread_weighted_order(
+                [boost if self._is_favorite_game(g) else 1 for g in self.games_list]
+            )
+            self._switch_order_key = key
+            self._switch_position = -1
+        order = self._switch_order
+        position = getattr(self, "_switch_position", -1)
+        if not 0 <= position < len(order) or order[position] != self.current_game_index:
+            position = (order.index(self.current_game_index)
+                        if self.current_game_index in order else -1)
+        position = (position + 1) % len(order)
+        self._switch_position = position
+        return order[position]
+
+    def _odds_color(self) -> Tuple[int, int, int]:
+        """Colour for the odds text; the green it always drew unless configured.
+
+        Guarded with getattr because not every class that reaches
+        _draw_dynamic_odds carries the element-colour helper -- the plugins'
+        own test harnesses build minimal manager objects, and a bare
+        AttributeError here is swallowed by the surrounding except, which
+        drops the odds off the card instead of failing loudly.
+        """
+        getter = getattr(self, "_element_color", None)
+        if getter is None:
+            return (0, 255, 0)
+        try:
+            return getter("odds_text", (0, 255, 0))  # pylint: disable=not-callable
+        except Exception:
+            return (0, 255, 0)
+
+    def _upcoming_date_and_time_text(self, game_date: str, game_time: str,
+                                     game: Optional[Dict] = None) -> Tuple[str, str]:
+        """The formatted (date, time) pair, blanked by switch_show_date/_time.
+
+        Deliberately not the shared show_date/show_time: those governed only
+        the scroll and Vegas cards before this display read the block, so a
+        config that had turned them off there would silently blank a scorebug
+        that has always drawn both lines. The switch keys default to True for
+        the same reason switch_upcoming_center defaults to "date_time" -- an
+        untouched panel keeps rendering exactly what it rendered before.
+        """
+        date_text = (self._format_game_date(game_date, game)
+                     if self._card_option("switch_show_date", True) else "")
+        time_text = (self._format_game_time(game_time)
+                     if self._card_option("switch_show_time", True) else "")
+        return date_text, time_text

test/test_api_v3_display_hardware.py

@@ -0,0 +1,222 @@
+"""Display hardware settings accept what the rgbmatrix library accepts.
+
+Held to the ranges in the pinned library (RGBMatrix::Options::Validate in
+lib/options-initialize.cc, the gpio_slowdown check in lib/led-matrix.cc), with
+one deliberate exception: rows has no upper bound here, although the library
+currently rejects more than 64 per panel. Two ways this used to go wrong:
+
+- The Display form capped cols at 128, chain_length at 24 and
+  pwm_lsb_nanoseconds at 500, and its submit handler (fixInvalidNumberInputs)
+  rewrites anything past an input's min/max to that bound -- so a wide panel or
+  a long chain silently saved as the wrong size.
+- The API checked none of these, so a value the library rejects (odd rows,
+  parallel 4, pwm_dither_bits 3) saved, and the matrix then refused to start.
+
+Row address type 5 is the SM5368 / B707 row shift register the Waveshare 96x48
+V2 needs (Waveshare's own "96X48_1_24_SM5368" panel type in their library fork
+just sets rows/cols, row_address_type=5 and BGR); the API used to stop at 4.
+"""
+import copy
+import json
+import re
+import sys
+from pathlib import Path
+from unittest.mock import MagicMock
+
+import pytest
+from flask import Flask
+
+PROJECT_ROOT = Path(__file__).parent.parent
+sys.path.insert(0, str(PROJECT_ROOT))
+
+from test._api_v3_test_helpers import api_v3_client, api_v3_module  # noqa: F401,E402
+from test.test_web_settings_ui import REALISTIC_CONFIG  # noqa: E402
+
+#: What a Waveshare RGB-Matrix-P2.5-96x48 V2 (back silkscreen 24S-A1) needed on
+#: a Pi 4 with an Adafruit Triple LED Matrix Bonnet, checked on the panel.
+WAVESHARE_96X48_V2 = {
+    'rows': 48, 'cols': 96, 'chain_length': 1, 'parallel': 1,
+    'hardware_mapping': 'regular', 'panel_type': '', 'row_address_type': 5,
+    'led_rgb_sequence': 'BGR', 'gpio_slowdown': 8,
+}
+
+#: Fields stored under display.runtime; the rest go under display.hardware.
+RUNTIME_FIELDS = {'gpio_slowdown'}
+
+
+def _stored(config, field):
+    section = 'runtime' if field in RUNTIME_FIELDS else 'hardware'
+    return config['display'][section][field]
+
+
+def _post(client, body):
+    return client.post('/api/v3/config/main', data=json.dumps(body),
+                       content_type='application/json')
+
+
+@pytest.fixture
+def saved(api_v3_module, monkeypatch):
+    """Capture what save_main_config would write.
+
+    Asserting on the stored value, not just the status code, is what shows the
+    value passed validation and landed where DisplayManager reads it.
+    """
+    captured = {}
+    api_v3_module.api_v3.config_manager.load_config.return_value = {}
+
+    def fake_save(_manager, config, **_kwargs):
+        captured['config'] = config
+        return True, ''
+
+    monkeypatch.setattr(api_v3_module, '_save_config_atomic', fake_save)
+    return captured
+
+
+@pytest.mark.parametrize('as_strings', [False, True], ids=['json-numbers', 'form-strings'])
+def test_waveshare_96x48_v2_settings_all_save(api_v3_client, saved, as_strings):
+    """The Display form posts every value as a string (json-enc); API clients send numbers."""
+    body = {k: str(v) if as_strings else v for k, v in WAVESHARE_96X48_V2.items()}
+    response = _post(api_v3_client, body)
+    assert response.status_code == 200, response.get_data(as_text=True)[:200]
+    for field, value in WAVESHARE_96X48_V2.items():
+        assert _stored(saved['config'], field) == value, field
+
+
+@pytest.mark.parametrize('field,value', [
+    ('rows', 8), ('rows', 64), ('rows', 96), ('rows', 128),
+    ('cols', 16), ('cols', 192), ('cols', 512),
+    ('chain_length', 1), ('chain_length', 32),
+    ('parallel', 3),
+    ('row_address_type', 0), ('row_address_type', 5), ('row_address_type', 5.0),
+    ('multiplexing', 0), ('multiplexing', 22),
+    ('gpio_slowdown', 0), ('gpio_slowdown', 10),
+    ('pwm_bits', 1), ('pwm_bits', 11),
+    ('pwm_dither_bits', 0), ('pwm_dither_bits', 2),
+    ('pwm_lsb_nanoseconds', 50), ('pwm_lsb_nanoseconds', 3000),
+    ('scan_mode', 1),
+    ('brightness', 1), ('brightness', 100),
+    ('limit_refresh_rate_hz', 0), ('limit_refresh_rate_hz', 1000),
+])
+def test_values_in_range_are_saved(api_v3_client, saved, field, value):
+    response = _post(api_v3_client, {field: value})
+    assert response.status_code == 200, response.get_data(as_text=True)[:200]
+    assert _stored(saved['config'], field) == value
+
+
+@pytest.mark.parametrize('field,value', [
+    ('rows', 6), ('rows', 47), ('rows', 97), ('rows', '48.5'),
+    ('cols', 15), ('cols', 96.5), ('cols', True), ('cols', 'wide'),
+    ('chain_length', 0),
+    ('parallel', 0), ('parallel', 4),
+    ('row_address_type', -1), ('row_address_type', 6),
+    ('row_address_type', True), ('row_address_type', 5.5),
+    ('multiplexing', -1), ('multiplexing', 23), ('multiplexing', True),
+    ('gpio_slowdown', -1), ('gpio_slowdown', 11),
+    ('pwm_bits', 0), ('pwm_bits', 12),
+    ('pwm_dither_bits', 3),
+    ('pwm_lsb_nanoseconds', 49), ('pwm_lsb_nanoseconds', 3001),
+    ('scan_mode', 2),
+    ('brightness', 0), ('brightness', 101),
+    ('limit_refresh_rate_hz', -1),
+])
+def test_values_out_of_range_are_refused(api_v3_client, saved, field, value):
+    """Refused with a message naming the field, and nothing written."""
+    response = _post(api_v3_client, {field: value})
+    assert response.status_code == 400
+    assert field in response.get_json()['message']
+    assert 'config' not in saved
+
+
+@pytest.fixture
+def display_page(monkeypatch):
+    """Render the Display settings partial for a given config."""
+    from web_interface.blueprints import pages_v3 as pv
+
+    def render(config):
+        base = PROJECT_ROOT / 'web_interface'
+        app = Flask(__name__, template_folder=str(base / 'templates'),
+                    static_folder=str(base / 'static'))
+        app.config['TESTING'] = True
+        config_manager = MagicMock()
+        config_manager.load_config.return_value = config
+        config_manager.get_raw_file_content.return_value = config
+        config_manager.get_config_path.return_value = 'config/config.json'
+        config_manager.get_secrets_path.return_value = 'config/config_secrets.json'
+        monkeypatch.setattr(pv.pages_v3, 'config_manager', config_manager, raising=False)
+        monkeypatch.setattr(pv.pages_v3, 'plugin_manager', MagicMock(plugins={}), raising=False)
+        app.register_blueprint(pv.pages_v3, url_prefix='/v3')
+        response = app.test_client().get('/v3/partials/display')
+        assert response.status_code == 200
+        return response.get_data(as_text=True)
+
+    return render
+
+
+def _config_with(hardware=None, runtime=None):
+    config = copy.deepcopy(REALISTIC_CONFIG)
+    config['display']['hardware'].update(hardware or {})
+    config['display']['runtime'].update(runtime or {})
+    return config
+
+
+def _input_tag(body, input_id):
+    match = re.search(r'<input[^>]*\bid="%s"[^>]*>' % re.escape(input_id), body)
+    assert match, f'no <input id="{input_id}">'
+    return match.group(0)
+
+
+def _attr(tag, name):
+    match = re.search(r'\s%s="([^"]*)"' % name, tag)
+    return match.group(1) if match else None
+
+
+def _selected_option(body, select_id):
+    select = re.search(r'<select id="%s".*?</select>' % select_id, body, re.S)
+    assert select, f'no <select id="{select_id}">'
+    return re.findall(r'<option value="([^"]*)"\s+selected\s*>', select.group(0))
+
+
+@pytest.mark.parametrize('input_id,expected', [
+    ('rows', {'min': '8', 'max': None, 'step': '2'}),
+    ('cols', {'min': '16', 'max': None}),
+    ('chain_length', {'min': '1', 'max': None}),
+    ('parallel', {'min': '1', 'max': '3'}),
+    ('gpio_slowdown', {'min': '0', 'max': '10'}),
+    ('pwm_bits', {'min': '1', 'max': '11'}),
+    ('pwm_dither_bits', {'min': '0', 'max': '2'}),
+    ('pwm_lsb_nanoseconds', {'min': '50', 'max': '3000'}),
+    ('limit_refresh_rate_hz', {'min': '0', 'max': '1000'}),
+])
+def test_form_limits_match_the_library(display_page, input_id, expected):
+    """fixInvalidNumberInputs rewrites a value past min/max on submit, so these
+    attributes are the real limits: a max below the library's clamps panels
+    that would work, and one above it saves a value the matrix rejects."""
+    tag = _input_tag(display_page(_config_with()), input_id)
+    for name, value in expected.items():
+        assert _attr(tag, name) == value, f'{input_id} {name}'
+
+
+def test_waveshare_96x48_v2_config_renders_back_unchanged(display_page):
+    """Saving the Display tab posts what it rendered, so each value must render as stored.
+
+    Before row address type 5 was in the dropdown no option was selected, the
+    browser posted the first one (0), and one save scrambled the panel again.
+    """
+    hardware = {k: v for k, v in WAVESHARE_96X48_V2.items() if k not in RUNTIME_FIELDS}
+    body = display_page(_config_with(hardware=hardware, runtime={'gpio_slowdown': 8}))
+
+    assert _selected_option(body, 'row_address_type') == ['5']
+    assert _selected_option(body, 'led_rgb_sequence') == ['BGR']
+    assert _selected_option(body, 'hardware_mapping') == ['regular']
+    for input_id in ('rows', 'cols', 'chain_length', 'parallel', 'gpio_slowdown'):
+        assert _attr(_input_tag(body, input_id), 'value') == str(WAVESHARE_96X48_V2[input_id]), input_id
+
+
+@pytest.mark.parametrize('field,section', [
+    ('gpio_slowdown', 'runtime'), ('pwm_dither_bits', 'hardware'),
+    ('limit_refresh_rate_hz', 'hardware'),
+])
+def test_a_stored_zero_renders_as_zero(display_page, field, section):
+    """`value or default` showed a stored 0 as the default, and the next save wrote it back."""
+    body = display_page(_config_with(**{section: {field: 0}}))
+    assert _attr(_input_tag(body, field), 'value') == '0'

test/test_common_is_hardware_free.py

@@ -0,0 +1,163 @@
+"""src/common must stay importable without display hardware.
+
+Plugins import src.common.sports_* in place of their bundled copies. If any of
+those modules reaches src.display_manager (and through it rgbmatrix) or the
+src.base_classes package (whose core.py imports DisplayManager), a scoreboard
+adopting it acquires a hardware dependency it never had, and the headless
+tooling -- the web preview, check_plugin.py, these tests on a laptop -- stops
+being able to load it.
+
+Two checks, because each misses what the other catches:
+
+1. A real import in a fresh interpreter with rgbmatrix made unimportable.
+   Catches indirect imports (common -> X -> display_manager) that no text scan
+   of src/common would see.
+2. An AST scan of src/common/*.py for module-level imports of the hardware and
+   plugin-system packages. Catches a direct import even where the target
+   happens to import cleanly on this machine.
+"""
+
+import ast
+import subprocess
+import sys
+import textwrap
+from pathlib import Path
+
+REPO_ROOT = Path(__file__).resolve().parents[1]
+COMMON = REPO_ROOT / "src" / "common"
+
+FORBIDDEN = ("src.base_classes", "src.display_manager", "src.plugin_system")
+
+#: Existing module-level violations, by file name, each with the reason it is
+#: tolerated. Empty when this test was added (core 3.4.0 + sports_helpers):
+#: no src/common module imported any of FORBIDDEN at module level. Add to this
+#: only with a comment saying why, never to get a new import past the test.
+ALLOWLIST = {}
+
+
+def test_sports_modules_import_without_hardware():
+    modules = sorted(p.stem for p in COMMON.glob("sports_*.py"))
+    assert "sports_helpers" in modules
+    script = textwrap.dedent(f"""
+        import importlib, json, sys
+        sys.modules["rgbmatrix"] = None   # any import of it now raises
+        importlib.import_module("src.common")
+        for name in {modules!r}:
+            importlib.import_module("src.common." + name)
+        loaded = sorted(m for m in sys.modules
+                        if m.startswith({FORBIDDEN!r}))
+        print(json.dumps(loaded))
+    """)
+    result = subprocess.run(
+        [sys.executable, "-c", script], cwd=str(REPO_ROOT),
+        capture_output=True, text=True, timeout=120)
+    assert result.returncode == 0, (
+        f"importing src.common without rgbmatrix failed:\n{result.stderr}")
+    loaded = result.stdout.strip().splitlines()[-1]
+    assert loaded == "[]", f"src.common pulled in hardware modules: {loaded}"
+
+
+def _module_level_imports(tree):
+    """Imports executed at import time: top level, including inside if/try
+    blocks, but not inside functions or classes (those are deferred)."""
+    stack = list(tree.body)
+    while stack:
+        node = stack.pop()
+        if isinstance(node, (ast.Import, ast.ImportFrom)):
+            yield node
+        elif isinstance(node, (ast.If, ast.Try, ast.With)):
+            stack.extend(node.body)
+            stack.extend(getattr(node, "orelse", []))
+            stack.extend(getattr(node, "finalbody", []))
+            for handler in getattr(node, "handlers", []):
+                stack.extend(handler.body)
+
+
+def _targets(node, package="src.common"):
+    """Absolute dotted names an import can load. Relative imports resolve
+    against ``package``, the scanned module's package."""
+    if isinstance(node, ast.Import):
+        return [alias.name for alias in node.names]
+    base = node.module
+    if node.level:
+        parts = package.split(".")
+        if node.level > len(parts):
+            return []   # beyond the top-level package; Python rejects it too
+        anchor = ".".join(parts[:len(parts) - node.level + 1])
+        base = f"{anchor}.{node.module}" if node.module else anchor
+    if base is None:
+        return []
+    # `from pkg import name` may load the submodule pkg.name.
+    return [base] + [f"{base}.{alias.name}" for alias in node.names
+                     if alias.name != "*"]
+
+
+def _violations():
+    found = {}
+    for path in sorted(COMMON.glob("*.py")):
+        tree = ast.parse(path.read_text(encoding="utf-8"), filename=str(path))
+        for node in _module_level_imports(tree):
+            for target in _targets(node, "src.common"):
+                if target == FORBIDDEN or any(
+                        target == f or target.startswith(f + ".") for f in FORBIDDEN):
+                    found.setdefault(path.name, []).append(f"line {node.lineno}: {target}")
+    return found
+
+
+def test_no_module_level_hardware_or_plugin_system_imports():
+    found = {name: hits for name, hits in _violations().items() if name not in ALLOWLIST}
+    assert found == {}, (
+        "src/common must not import these at module level (defer the import "
+        f"into the function that needs it): {found}")
+
+
+def test_allowlist_has_no_stale_entries():
+    stale = sorted(set(ALLOWLIST) - set(_violations()))
+    assert stale == [], f"allowlisted but no longer violating, remove: {stale}"
+
+
+def test_the_scan_sees_a_direct_import(tmp_path):
+    # Guard the guard: the walker must find imports nested in try/if.
+    tree = ast.parse(textwrap.dedent("""
+        try:
+            from src.display_manager import DisplayManager
+        except ImportError:
+            pass
+        if True:
+            import src.base_classes.sports
+        from src import plugin_system
+        def later():
+            from src.display_manager import DisplayManager
+    """))
+    targets = {t for n in _module_level_imports(tree) for t in _targets(n)}
+    assert {"src.base_classes.sports", "src.display_manager",
+            "src.plugin_system"} <= targets
+
+
+def test_the_scan_resolves_relative_imports():
+    # A module in src/common reaches src.plugin_system through `..`.
+    tree = ast.parse(textwrap.dedent("""
+        from .. import plugin_system
+        from ..plugin_system import plugin_manager
+        from . import sports_shared
+    """))
+    targets = {t for n in _module_level_imports(tree)
+               for t in _targets(n, "src.common")}
+    assert {"src.plugin_system", "src.plugin_system.plugin_manager",
+            "src.common.sports_shared"} <= targets
+    # The package decides where `..` points.
+    node = ast.parse("from .. import plugin_system").body[0]
+    assert _targets(node, "src.common") == ["src", "src.plugin_system"]
+    assert _targets(node, "a.b") == ["a", "a.plugin_system"]
+
+
+def test_the_scan_flags_relative_imports_in_src_common(monkeypatch, tmp_path):
+    # End to end through _violations(): both relative forms are reported.
+    (tmp_path / "bad.py").write_text(
+        "from .. import plugin_system\nfrom ..plugin_system import x\n",
+        encoding="utf-8")
+    monkeypatch.setitem(globals(), "COMMON", tmp_path)
+    found = {name: sorted(hits) for name, hits in _violations().items()}
+    assert found == {"bad.py": ["line 1: src.plugin_system",
+                                "line 2: src.plugin_system",
+                                "line 2: src.plugin_system.x"]}

test/test_sports_helpers.py

@@ -0,0 +1,603 @@
+"""src.common.sports_helpers: behaviour, host contract, and parity with the plugins.
+
+The bodies were copied from the scoreboard plugins' sports.py, so the plugins'
+own tests already cover them there. They are ported here for two reasons: core
+now owns a copy that can drift on its own, and a plugin that deletes its copy
+loses those tests with it.
+
+The parity class is what keeps "byte-identical" true after this lands. Point
+LEDMATRIX_PLUGINS at a ledmatrix-plugins checkout and every promoted body is
+compared, as a docstring-stripped AST, against every plugin copy that carries
+it. Without the variable it skips rather than fails, since core CI has no
+plugins checkout; ledmatrix-plugins CI runs the same comparison against core
+(scripts/check_sports_helpers_parity.py, ledmatrix-plugins#495).
+"""
+
+import ast
+import logging
+import math
+import os
+import time
+from pathlib import Path
+
+import pytest
+from PIL import Image
+from PIL.PngImagePlugin import PngInfo
+
+from src.common import sports_helpers
+from src.common.sports_helpers import (
+    MAX_WINDOW_DAYS,
+    MIN_WINDOW_DAYS,
+    SportsHelpersMixin,
+    clamp_seconds,
+    clamp_window,
+    logo_needs_refresh,
+    spread_weighted_order,
+)
+from src.common.sports_shared import SportsCoreSharedMixin
+
+
+# ---------------------------------------------------------------------------
+# Free functions
+# ---------------------------------------------------------------------------
+
+class TestClampWindow:
+    def test_within_range_is_kept(self):
+        assert clamp_window(14, 7) == 14
+        assert clamp_window("30", 7) == 30
+
+    def test_clamped_to_bounds(self):
+        assert (MIN_WINDOW_DAYS, MAX_WINDOW_DAYS) == (1, 60)
+        assert clamp_window(0, 7) == 1
+        assert clamp_window(-5, 7) == 1
+        assert clamp_window(365, 7) == 60
+
+    @pytest.mark.parametrize("bad", [None, "abc", [], {}, float("nan")])
+    def test_unusable_falls_back(self, bad):
+        assert clamp_window(bad, 7) == 7
+
+    @pytest.mark.parametrize("inf", [float("inf"), float("-inf")])
+    def test_infinity_falls_back_instead_of_raising(self, inf):
+        # json.loads accepts a bare Infinity; int(inf) raises OverflowError.
+        with pytest.raises(OverflowError):
+            int(inf)
+        assert clamp_window(inf, 7) == 7
+
+
+class TestClampSeconds:
+    def test_defaults_bound_five_seconds_to_a_day(self):
+        assert clamp_seconds(1, 60) == 5
+        assert clamp_seconds(10 ** 9, 60) == 86400
+        assert clamp_seconds(300, 60) == 300
+
+    def test_custom_bounds(self):
+        assert clamp_seconds(1, 60, low=30, high=900) == 30
+        assert clamp_seconds(5000, 60, low=30, high=900) == 900
+
+    @pytest.mark.parametrize("bad", [None, "x", float("nan"), float("inf")])
+    def test_unusable_falls_back(self, bad):
+        assert clamp_seconds(bad, 60) == 60
+
+
+def _png(path, size=(64, 64), color=(100, 100, 100, 255), marker=None):
+    img = Image.new("RGBA", size, color)
+    info = None
+    if marker is not None:
+        info = PngInfo()
+        info.add_text("ledmatrix_placeholder", marker)
+    img.save(path, "PNG", pnginfo=info)
+    return path
+
+
+class TestLogoNeedsRefresh:
+    def test_stale_placeholder_is_retried(self, tmp_path):
+        from src.logo_downloader import PLACEHOLDER_RETRY_SECONDS
+        stamp = str(time.time() - PLACEHOLDER_RETRY_SECONDS - 60)
+        assert logo_needs_refresh(_png(tmp_path / "A.png", marker=stamp)) is True
+
+    def test_fresh_placeholder_is_trusted(self, tmp_path):
+        assert logo_needs_refresh(_png(tmp_path / "A.png", marker=str(time.time()))) is False
+
+    def test_real_logo_is_never_refreshed(self, tmp_path):
+        assert logo_needs_refresh(_png(tmp_path / "A.png", size=(32, 32),
+                                       color=(200, 0, 0, 255))) is False
+
+    def test_missing_file_is_not_a_placeholder(self, tmp_path):
+        assert logo_needs_refresh(tmp_path / "nope.png") is False
+
+    def test_core_without_placeholder_marking_keeps_old_behaviour(self, monkeypatch, tmp_path):
+        # A None entry in sys.modules makes the import raise ImportError, the
+        # same thing an older core without these names does.
+        monkeypatch.setitem(__import__("sys").modules, "src.logo_downloader", None)
+        stamp = str(time.time() - 10 ** 7)
+        assert logo_needs_refresh(_png(tmp_path / "A.png", marker=stamp)) is False
+
+    def test_the_import_is_deferred(self):
+        tree = ast.parse(Path(sports_helpers.__file__).read_text(encoding="utf-8"))
+        top = [n for n in tree.body if isinstance(n, (ast.Import, ast.ImportFrom))]
+        assert not any(isinstance(n, ast.ImportFrom) and n.module == "src.logo_downloader"
+                       for n in top)
+
+
+def _back_to_back(cycle):
+    return any(cycle[i] == cycle[(i + 1) % len(cycle)] for i in range(len(cycle)))
+
+
+class TestSpreadWeightedOrder:
+    def test_equal_weights_are_plain_order(self):
+        assert spread_weighted_order([1, 1, 1]) == [0, 1, 2]
+        assert spread_weighted_order([]) == []
+
+    def test_a_favourite_at_the_end_wraps_its_extra_turn(self):
+        order = spread_weighted_order([1, 1, 1, 2])
+        assert sorted(order) == [0, 1, 2, 3, 3]
+        assert not _back_to_back(order)
+
+    @pytest.mark.parametrize("weights,expected", [
+        ([3, 1, 1], [0, 1, 0, 2, 0]),
+        ([1, 3, 1], [0, 1, 1, 2, 1]),
+        ([5, 1], None),
+        ([2, 1], None),
+    ])
+    def test_ratio_wins_over_spacing(self, weights, expected):
+        order = spread_weighted_order(weights)
+        assert [order.count(i) for i in range(len(weights))] == weights
+        if expected is not None:
+            assert order == expected
+
+    def test_mixin_exposes_it_as_a_staticmethod(self):
+        assert SportsHelpersMixin._spread_weighted_order([1, 2]) == spread_weighted_order([1, 2])
+        assert isinstance(SportsHelpersMixin.__dict__["_spread_weighted_order"], staticmethod)
+
+
+# ---------------------------------------------------------------------------
+# Mixin methods, against stand-in hosts carrying only what each reads
+# ---------------------------------------------------------------------------
+
+class _Dwell(SportsHelpersMixin):
+    def __init__(self, last_game_switch):
+        self._last_display_call_monotonic = 0.0
+        self.last_game_switch = last_game_switch
+
+
+class TestResetDwellOnReentry:
+    def test_first_frame_resets(self):
+        mgr = _Dwell(time.time() - 6.0)
+        assert mgr._reset_dwell_on_reentry() is True
+        assert time.time() - mgr.last_game_switch < 1.0
+
+    def test_frames_inside_one_stint_do_not(self):
+        mgr = _Dwell(time.time() - 6.0)
+        mgr._reset_dwell_on_reentry()
+        stamp = mgr.last_game_switch
+        assert [mgr._reset_dwell_on_reentry() for _ in range(3)] == [False] * 3
+        assert mgr.last_game_switch == stamp
+
+    def test_returning_after_a_long_gap_resets(self):
+        mgr = _Dwell(time.time() - 150.0)
+        mgr._last_display_call_monotonic = time.monotonic() - 150.0
+        assert mgr._reset_dwell_on_reentry() is True
+
+    def test_just_under_the_threshold_is_the_same_stint(self):
+        mgr = _Dwell(time.time() - 150.0)
+        mgr._last_display_call_monotonic = time.monotonic() - (
+            SportsHelpersMixin._DWELL_REENTRY_GAP_SECONDS - 1.0)
+        stamp = mgr.last_game_switch
+        assert mgr._reset_dwell_on_reentry() is False
+        assert mgr.last_game_switch == stamp
+
+    def test_live_zero_sentinel_survives(self):
+        mgr = _Dwell(0)
+        assert mgr._reset_dwell_on_reentry() is False
+        assert mgr.last_game_switch == 0
+
+    def test_host_without_any_state(self):
+        mgr = SportsHelpersMixin()
+        assert mgr._reset_dwell_on_reentry() is False  # no last_game_switch
+        assert mgr._last_display_call_monotonic > 0
+
+
+def _game(gid, home="X", away="Y"):
+    return {"id": gid, "home_abbr": home, "away_abbr": away}
+
+
+class _Switch(SportsHelpersMixin):
+    def __init__(self, games, boost=None, favorites=("UF",)):
+        self.games_list = games
+        self.favorite_teams = list(favorites)
+        if boost is not None:
+            self.favorite_rotation_boost = boost
+        self.current_game_index = 0
+
+    def _is_favorite_game(self, g):
+        return g["home_abbr"] in self.favorite_teams or g["away_abbr"] in self.favorite_teams
+
+    def walk(self, steps):
+        shown = []
+        for _ in range(steps):
+            self.current_game_index = self._next_switch_index()
+            shown.append(self.games_list[self.current_game_index]["id"])
+        return shown
+
+
+class TestNextSwitchIndex:
+    def test_no_boost_attribute_is_the_plain_rotation(self):
+        s = _Switch([_game("a"), _game("b", "UF"), _game("c")])
+        assert s.walk(6) == ["b", "c", "a", "b", "c", "a"]
+
+    def test_boost_without_a_favourite_changes_nothing(self):
+        assert _Switch([_game("a"), _game("b"), _game("c")], boost=3).walk(3) == ["b", "c", "a"]
+
+    def test_boost_two_spreads_the_favourite(self):
+        s = _Switch([_game("a"), _game("uf", "UF"), _game("c"), _game("d")], boost=2)
+        cycle = s.walk(5)
+        assert sorted(cycle) == ["a", "c", "d", "uf", "uf"]
+        assert not _back_to_back(cycle)
+        assert s.walk(5) == cycle
+
+    def test_boost_three_two_favourites(self):
+        s = _Switch([_game("a", "UF"), _game("b"), _game("c", "FSU"), _game("d"), _game("e")],
+                    boost=3, favorites=("UF", "FSU"))
+        cycle = s.walk(9)
+        assert cycle.count("a") == 3 and cycle.count("c") == 3
+
+    def test_index_reset_by_update_is_followed(self):
+        s = _Switch([_game("a"), _game("uf", "UF"), _game("c"), _game("d")], boost=2)
+        s.walk(3)
+        s.current_game_index = 0
+        assert s.walk(1)[0] == "uf"
+
+    def test_single_card_stays_put(self):
+        assert _Switch([_game("uf", "UF")], boost=5).walk(3) == ["uf", "uf", "uf"]
+
+
+class _Settings(SportsHelpersMixin):
+    def __init__(self, mode_config):
+        self.mode_config = mode_config
+        self.logger = logging.getLogger("test.sports_helpers")
+        self.league = "nfl"
+
+
+class TestSettingInt:
+    def test_reads_and_clamps(self):
+        assert _Settings({"n": 3})._setting_int("n", 1, 1, 5) == 3
+        assert _Settings({"n": "4"})._setting_int("n", 1, 1, 5) == 4
+        assert _Settings({"n": 99})._setting_int("n", 1, 1, 5) == 5
+        assert _Settings({"n": -2})._setting_int("n", 1, 1, 5) == 1
+        assert _Settings({})._setting_int("n", 2, 1, 5) == 2
+
+    @pytest.mark.parametrize("bad", ["abc", None, [], float("inf"), float("nan")])
+    def test_unusable_falls_back_with_a_warning(self, bad, caplog):
+        with caplog.at_level(logging.WARNING, logger="test.sports_helpers"):
+            assert _Settings({"n": bad})._setting_int("n", 2, 1, 5) == 2
+        assert "ignoring unusable n" in caplog.text
+
+
+class _Custom(SportsHelpersMixin):
+    def __init__(self, config, mode=None):
+        self.config = config
+        if mode is not None:
+            self.SKIN_MODE = mode
+
+
+class TestModeCustomization:
+    def test_no_mode_returns_block_as_is(self):
+        cust = {"score": {"font_size": 10}}
+        assert _Custom({"customization": cust})._mode_customization() is cust
+
+    def test_non_dict_customization(self):
+        assert _Custom({"customization": "junk"}, "live")._mode_customization() == {}
+        assert _Custom({}, "live")._mode_customization() == {}
+
+    def test_mode_overrides_merge_and_none_inherits(self):
+        cfg = {"customization": {
+            "score": {"font_size": 10, "text_color": [1, 1, 1]},
+            "layout": {"score": {"x_offset": 2, "y_offset": 3}},
+            "modes": {"live": {
+                "score": {"font_size": 12, "text_color": None},
+                "status": "not-a-dict",
+                "layout": {"score": {"y_offset": 0, "x_offset": None}, "bad": 5},
+            }},
+        }}
+        merged = _Custom(cfg, "live")._mode_customization()
+        assert merged["score"] == {"font_size": 12, "text_color": [1, 1, 1]}
+        assert merged["layout"]["score"] == {"x_offset": 2, "y_offset": 0}
+        assert "bad" not in merged["layout"]
+        # The stored config is not mutated.
+        assert cfg["customization"]["score"]["font_size"] == 10
+        assert cfg["customization"]["layout"]["score"]["y_offset"] == 3
+
+    def test_other_mode_is_untouched(self):
+        cust = {"modes": {"live": {"score": {"font_size": 12}}}}
+        assert _Custom({"customization": cust}, "recent")._mode_customization() is cust
+
+
+class TestOddsColor:
+    def test_without_element_color_is_green(self):
+        assert SportsHelpersMixin()._odds_color() == (0, 255, 0)
+
+    def test_raising_getter_is_green(self):
+        class Host(SportsHelpersMixin):
+            def _element_color(self, element, default):
+                raise RuntimeError("boom")
+        assert Host()._odds_color() == (0, 255, 0)
+
+    def test_asks_for_odds_text_with_green_default(self):
+        seen = []
+
+        class Host(SportsHelpersMixin):
+            def _element_color(self, element, default):
+                seen.append((element, default))
+                return (9, 9, 9)
+        assert Host()._odds_color() == (9, 9, 9)
+        assert seen == [("odds_text", (0, 255, 0))]
+
+
+class _Scorebug(SportsHelpersMixin):
+    def __init__(self, scroll_card):
+        self.config = {"scroll_card": scroll_card}
+
+    def _card_option(self, key, default=None):
+        return SportsCoreSharedMixin._card_option(self, key, default)
+
+    def _format_game_date(self, game_date, game=None):
+        return "DATE"
+
+    def _format_game_time(self, game_time):
+        return "TIME"
+
+
+class TestUpcomingDateAndTimeText:
+    def _text(self, block):
+        return _Scorebug(block)._upcoming_date_and_time_text("2026-10-07", "19:00")
+
+    def test_defaults_draw_both(self):
+        assert self._text({}) == ("DATE", "TIME")
+
+    def test_scroll_card_toggles_do_not_reach_the_scorebug(self):
+        assert self._text({"show_date": False, "show_time": False}) == ("DATE", "TIME")
+
+    def test_switch_toggles(self):
+        assert self._text({"switch_show_date": False}) == ("", "TIME")
+        assert self._text({"switch_show_time": False}) == ("DATE", "")
+
+
+class TestFavoriteKey:
+    def test_defaults_to_abbreviation(self):
+        assert SportsHelpersMixin()._favorite_key({"home_abbr": "UF"}, "home") == "UF"
+
+    def test_missing_abbreviation_never_matches(self):
+        assert SportsHelpersMixin()._favorite_key({}, "away") is None
+
+
+# ---------------------------------------------------------------------------
+# Host contract
+# ---------------------------------------------------------------------------
+
+def _self_reads():
+    """Every ``self.X`` / ``getattr(self, "X")`` the mixin reads, by parsing it."""
+    tree = ast.parse(Path(sports_helpers.__file__).read_text(encoding="utf-8"))
+    cls = next(n for n in tree.body
+               if isinstance(n, ast.ClassDef) and n.name == "SportsHelpersMixin")
+    names = set()
+    for node in ast.walk(cls):
+        if (isinstance(node, ast.Attribute) and isinstance(node.ctx, ast.Load)
+                and isinstance(node.value, ast.Name) and node.value.id == "self"):
+            names.add(node.attr)
+        if (isinstance(node, ast.Call) and isinstance(node.func, ast.Name)
+                and node.func.id == "getattr" and len(node.args) >= 2
+                and isinstance(node.args[0], ast.Name) and node.args[0].id == "self"
+                and isinstance(node.args[1], ast.Constant)):
+            names.add(node.args[1].value)
+    return names
+
+
+class _Host(SportsCoreSharedMixin, SportsHelpersMixin):
+    """The smallest thing a scoreboard's SportsCore has to be for these to run."""
+
+    def __init__(self, config, mode_config=None):
+        self.config = config
+        self.mode_config = mode_config or {}
+        self.logger = logging.getLogger("test.sports_helpers.host")
+        self.games_list = []
+        self.current_game_index = 0
+        self.last_game_switch = 0
+
+    def _is_favorite_game(self, game):
+        return game.get("home_abbr") == "UF"
+
+
+class TestHostContract:
+    def test_every_host_read_is_documented(self):
+        defined = set(dir(SportsHelpersMixin))
+        # Written by the mixin itself before (or instead of) being read.
+        own_state = {"_last_display_call_monotonic", "_switch_order",
+                     "_switch_order_key", "_switch_position"}
+        needed = _self_reads() - defined - own_state
+        doc = sports_helpers.__doc__
+        undocumented = sorted(n for n in needed | own_state if f"``{n}``" not in doc)
+        assert undocumented == [], (
+            f"self attributes read but not in the module docstring's host "
+            f"contract: {undocumented}")
+
+    def test_every_constant_read_has_a_default(self):
+        # SKIN_MODE is the one exception: the host's mode name, read with
+        # getattr(self, 'SKIN_MODE', None) where absence means "no mode". A
+        # default here would say nothing the getattr does not already.
+        missing = sorted(n for n in _self_reads() - {"SKIN_MODE"}
+                         if n.upper() == n and not hasattr(SportsHelpersMixin, n))
+        assert missing == []
+
+    def test_defaults_match_what_the_plugins_ship(self):
+        assert SportsHelpersMixin._DWELL_REENTRY_GAP_SECONDS == 5.0
+        assert SportsHelpersMixin.favorite_rotation_boost == 1
+
+    def test_stateless_and_constructor_free(self):
+        assert "__init__" not in SportsHelpersMixin.__dict__
+        assert SportsHelpersMixin().__dict__ == {}
+
+    def test_base_order_does_not_matter(self):
+        class Reversed(SportsHelpersMixin, SportsCoreSharedMixin):
+            __init__ = _Host.__init__
+            _is_favorite_game = _Host._is_favorite_game
+
+        for cls in (_Host, Reversed):
+            h = cls({"scroll_card": {"switch_show_time": False, "time_format": "24h"}})
+            assert h._upcoming_date_and_time_text("10/7", "7:00 PM") == ("10/7", "")
+
+    def test_shared_mixin_supplies_the_card_helpers(self):
+        h = _Host({"scroll_card": {"switch_date_format": "abbrev", "time_format": "24h"}})
+        assert h._upcoming_date_and_time_text("10/7", "7:05 PM") == ("Oct 7", "19:05")
+
+    def test_odds_color_resolves_through_element_style(self):
+        h = _Host({"customization": {"odds_text": {"text_color": [1, 2, 3]}}})
+        assert tuple(h._odds_color()) == (1, 2, 3)
+        assert tuple(_Host({})._odds_color()) == (0, 255, 0)
+
+    def test_rotation_settings_and_dwell_on_one_host(self):
+        h = _Host({}, mode_config={"favorite_rotation_boost": "2"})
+        h.favorite_rotation_boost = h._setting_int("favorite_rotation_boost", 1, 1, 5)
+        h.games_list = [_game("a"), _game("uf", "UF"), _game("c")]
+        seen = []
+        for _ in range(4):
+            h.current_game_index = h._next_switch_index()
+            seen.append(h.games_list[h.current_game_index]["id"])
+        assert sorted(seen) == ["a", "c", "uf", "uf"]
+        h.last_game_switch = time.time() - 100
+        assert h._reset_dwell_on_reentry() is True
+
+
+# ---------------------------------------------------------------------------
+# Parity with the plugin copies
+# ---------------------------------------------------------------------------
+
+SCOREBOARDS = ("afl", "baseball", "basketball", "football", "hockey",
+               "lacrosse", "nrl", "soccer", "ufc")
+
+#: core name -> (where it lives in the plugins' sports.py, plugin name,
+#: plugins expected to carry it).
+_ALL = SCOREBOARDS
+_NOT_UFC = tuple(p for p in SCOREBOARDS if p != "ufc")
+PROMOTED = {
+    "clamp_window": ("module", "_clamp_window", _ALL),
+    "clamp_seconds": ("module", "_clamp_seconds", _ALL),
+    "logo_needs_refresh": ("module", "_logo_needs_refresh", _ALL),
+    "spread_weighted_order": ("SportsCore", "_spread_weighted_order", _ALL),
+    "_mode_customization": ("SportsCore", "_mode_customization", _ALL),
+    "_setting_int": ("SportsCore", "_setting_int", _ALL),
+    "_reset_dwell_on_reentry": ("SportsCore", "_reset_dwell_on_reentry", _ALL),
+    "_next_switch_index": ("SportsCore", "_next_switch_index", _ALL),
+    "_odds_color": ("SportsCore", "_odds_color", _NOT_UFC),
+    "_upcoming_date_and_time_text": ("SportsCore", "_upcoming_date_and_time_text", _NOT_UFC),
+}
+
+#: Public names here that are private in the plugins.
+_RENAMES = {
+    "clamp_window": "_clamp_window",
+    "clamp_seconds": "_clamp_seconds",
+    "logo_needs_refresh": "_logo_needs_refresh",
+    "spread_weighted_order": "_spread_weighted_order",
+    "MIN_WINDOW_DAYS": "_MIN_WINDOW_DAYS",
+    "MAX_WINDOW_DAYS": "_MAX_WINDOW_DAYS",
+}
+
+
+def _plugins_root():
+    raw = os.environ.get("LEDMATRIX_PLUGINS")
+    if not raw:
+        pytest.skip("set LEDMATRIX_PLUGINS to a ledmatrix-plugins checkout to "
+                    "compare sports_helpers against the plugin copies; in CI "
+                    "this parity check runs in ledmatrix-plugins "
+                    "scripts/check_sports_helpers_parity.py (#495)")
+    root = Path(raw)
+    if (root / "plugins").is_dir():
+        root = root / "plugins"
+    if not (root / "football-scoreboard" / "sports.py").is_file():
+        pytest.skip(f"LEDMATRIX_PLUGINS={raw} has no football-scoreboard/sports.py")
+    return root
+
+
+class _Normalise(ast.NodeTransformer):
+    def visit_Name(self, node):
+        node.id = _RENAMES.get(node.id, node.id)
+        return node
+
+    def _func(self, node):
+        node.name = _RENAMES.get(node.name, node.name)
+        node.decorator_list = []
+        body = node.body
+        if (body and isinstance(body[0], ast.Expr)
+                and isinstance(body[0].value, ast.Constant)
+                and isinstance(body[0].value.value, str)):
+            node.body = body[1:] or [ast.Pass()]
+        self.generic_visit(node)
+        return node
+
+    visit_FunctionDef = _func
+
+
+def _dump(node):
+    node = ast.parse(ast.unparse(node)).body[0]   # detach and copy
+    return ast.dump(_Normalise().visit(node))
+
+
+def _definitions(tree):
+    module, core = {}, {}
+    for node in tree.body:
+        if isinstance(node, ast.FunctionDef):
+            module[node.name] = node
+        elif isinstance(node, ast.Assign) and isinstance(node.targets[0], ast.Name):
+            module[node.targets[0].id] = node
+        elif isinstance(node, ast.ClassDef) and node.name == "SportsCore":
+            for item in node.body:
+                if isinstance(item, ast.FunctionDef):
+                    core[item.name] = item
+                elif isinstance(item, (ast.Assign, ast.AnnAssign)):
+                    target = item.targets[0] if isinstance(item, ast.Assign) else item.target
+                    if isinstance(target, ast.Name):
+                        core[target.id] = item
+    return {"module": module, "SportsCore": core}
+
+
+def _core_definitions():
+    tree = ast.parse(Path(sports_helpers.__file__).read_text(encoding="utf-8"))
+    out = {}
+    for node in tree.body:
+        if isinstance(node, ast.FunctionDef):
+            out[node.name] = node
+        elif isinstance(node, ast.ClassDef) and node.name == "SportsHelpersMixin":
+            for item in node.body:
+                if isinstance(item, ast.FunctionDef):
+                    out[item.name] = item
+    return out
+
+
+class TestParityWithPlugins:
+    @pytest.mark.parametrize("name", sorted(PROMOTED))
+    def test_body_matches_every_plugin_copy(self, name):
+        root = _plugins_root()
+        where, plugin_name, carriers = PROMOTED[name]
+        ours = _dump(_core_definitions()[name])
+        drifted, missing = [], []
+        for sport in carriers:
+            defs = _definitions(ast.parse(
+                (root / f"{sport}-scoreboard" / "sports.py").read_text(encoding="utf-8")))
+            theirs = defs[where].get(plugin_name)
+            if theirs is None:
+                missing.append(sport)
+            elif _dump(theirs) != ours:
+                drifted.append(sport)
+        assert missing == [], f"{plugin_name} no longer in: {missing}"
+        assert drifted == [], (
+            f"{plugin_name} differs from src/common/sports_helpers.py in: {drifted}. "
+            f"Port the change to both, or stop treating it as shared.")
+
+    @pytest.mark.parametrize("sport", SCOREBOARDS)
+    def test_constants_match(self, sport):
+        root = _plugins_root()
+        defs = _definitions(ast.parse(
+            (root / f"{sport}-scoreboard" / "sports.py").read_text(encoding="utf-8")))
+        assert ast.literal_eval(defs["module"]["_MIN_WINDOW_DAYS"].value) == MIN_WINDOW_DAYS
+        assert ast.literal_eval(defs["module"]["_MAX_WINDOW_DAYS"].value) == MAX_WINDOW_DAYS
+        gap = defs["SportsCore"]["_DWELL_REENTRY_GAP_SECONDS"].value
+        assert math.isclose(ast.literal_eval(gap), SportsHelpersMixin._DWELL_REENTRY_GAP_SECONDS)

test/web_interface/test_x_display_hidden.py

@@ -0,0 +1,577 @@
+"""``"x-display": "hidden"`` keeps a setting declared but off the form.
+
+Plugins keep deprecated keys in their schema so configs that still carry them
+keep validating (weather's ``api_key`` and ``radar_zoom``, olympics'
+notification keys), and some keys are internal (countdown's auto-generated
+row ``id``). Drawn as live controls they invite edits that do nothing, or
+worse, change an internal id.
+
+The contract pinned here:
+
+* nothing hidden is drawn -- top level, nested, in Advanced Settings, or as an
+  array-table column -- and visible siblings still are;
+* an object of nothing but hidden children draws no empty section;
+* a hidden top-level key is not reported in ``__rendered_section`` and does
+  not count toward the Advanced Settings total;
+* saving the rendered form never changes a hidden value: plain and nested ones
+  are simply not posted (the save deep-merges over the stored section), and a
+  hidden array-row property is carried through JSON-encoded, because a posted
+  row replaces the stored item wholesale;
+* an unchecked *visible* checkbox beside them is still cleared;
+* a JSON API save is unaffected.
+"""
+
+import json
+import re
+import sys
+from html.parser import HTMLParser
+from pathlib import Path
+from unittest.mock import MagicMock
+
+import pytest
+from flask import Flask
+from werkzeug.datastructures import MultiDict
+
+PROJECT_ROOT = Path(__file__).parent.parent.parent
+sys.path.insert(0, str(PROJECT_ROOT))
+
+HIDDEN = {"x-display": "hidden"}
+
+SCHEMA = {
+    "type": "object",
+    "properties": {
+        "enabled": {"type": "boolean", "default": True},
+        "city": {"type": "string", "title": "City", "default": "Dallas"},
+        "legacy_key": {"type": "string", "title": "Legacy Key", **HIDDEN},
+        "legacy_flag": {"type": "boolean", "title": "Legacy Flag", **HIDDEN},
+        "timeout": {"type": "integer", "title": "Timeout", "default": 10,
+                    "x-advanced": True},
+        "old_zoom": {"type": "integer", "title": "Old Zoom", "default": 6,
+                     "minimum": 4, "maximum": 8, "x-advanced": True, **HIDDEN},
+        "display": {
+            "type": "object",
+            "title": "Display",
+            "properties": {
+                "show_clock": {"type": "boolean", "title": "Show Clock",
+                               "default": True},
+                "old_flag": {"type": "boolean", "title": "Old Flag", **HIDDEN},
+                "old_mode": {"type": "string", "title": "Old Mode", **HIDDEN},
+            },
+        },
+        # Every child hidden: no empty section.
+        "internal": {
+            "type": "object",
+            "title": "Internal Stuff",
+            "properties": {
+                "token_seen": {"type": "boolean", **HIDDEN},
+                "revision": {"type": "integer", **HIDDEN},
+            },
+        },
+        "entries": {
+            "type": "array",
+            "title": "Entries",
+            "x-widget": "array-table",
+            # x-columns naming a hidden property must not draw it either.
+            "x-columns": ["enabled", "name", "id"],
+            "items": {
+                "type": "object",
+                "properties": {
+                    "id": {"type": "string", "title": "Row ID", **HIDDEN},
+                    "enabled": {"type": "boolean", "default": True},
+                    "name": {"type": "string"},
+                    "pinned": {"type": "boolean", "title": "Pinned", **HIDDEN},
+                    "weight": {"type": "number", "title": "Weight", **HIDDEN},
+                    "layout": {
+                        "type": "object",
+                        "properties": {
+                            "x": {"type": "integer", "default": 0},
+                            "legacy_x": {"type": "integer", **HIDDEN},
+                        },
+                    },
+                },
+                "required": ["name"],
+            },
+        },
+    },
+}
+
+STORED = {
+    "enabled": True,
+    "city": "Dallas",
+    "legacy_key": "keep-me",
+    "legacy_flag": True,
+    "timeout": 10,
+    "old_zoom": 5,
+    "display": {"show_clock": True, "old_flag": True, "old_mode": "classic"},
+    "internal": {"token_seen": True, "revision": 7},
+    "entries": [
+        # An id that looks like a number must come back a string.
+        {"id": "1", "enabled": True, "name": "First", "pinned": True,
+         "weight": 2.5, "layout": {"x": 3, "legacy_x": 9}},
+        {"id": "cd_ab12cd34ef56", "enabled": False, "name": "Second",
+         "pinned": False},
+    ],
+}
+
+HIDDEN_LABELS = ("Legacy Key", "Legacy Flag", "Old Zoom", "Old Flag",
+                 "Old Mode", "Internal Stuff", "Row ID", "Pinned", "Weight")
+
+
+class _FormFields(HTMLParser):
+    """Collect what a browser would submit from the rendered form."""
+
+    def __init__(self):
+        super().__init__()
+        self.pairs = []
+        self._select = None
+        self._first = None
+        self._chosen = None
+
+    def handle_starttag(self, tag, attrs):
+        a = dict(attrs)
+        name = a.get("name")
+        if tag == "input" and name and "disabled" not in a:
+            if a.get("type") in ("checkbox", "radio") and "checked" not in a:
+                return
+            if a.get("type") in ("button", "submit", "file"):
+                return
+            self.pairs.append((name, a.get("value", "")))
+        elif tag == "select" and name:
+            self._select, self._first, self._chosen = name, None, None
+        elif tag == "option" and self._select:
+            if self._first is None:
+                self._first = a.get("value", "")
+            if "selected" in a:
+                self._chosen = a.get("value", "")
+
+    def handle_endtag(self, tag):
+        if tag == "select" and self._select:
+            chosen = self._chosen if self._chosen is not None else self._first
+            self.pairs.append((self._select, chosen or ""))
+            self._select = None
+
+
+def _render(schema, config, plugin_id="demo"):
+    from jinja2 import Environment, FileSystemLoader, select_autoescape
+
+    env = Environment(
+        loader=FileSystemLoader(str(PROJECT_ROOT / "web_interface" / "templates")),
+        autoescape=select_autoescape(["html"]),
+    )
+    plugin = {"id": plugin_id, "name": "Demo", "description": "",
+              "enabled": True, "author": "me", "version": "1.0.0"}
+    return env.get_template("v3/partials/plugin_config.html").render(
+        plugin=plugin, schema=schema, config=json.loads(json.dumps(config)))
+
+
+def _form_pairs(html):
+    parser = _FormFields()
+    parser.feed(html)
+    return parser.pairs
+
+
+def _names(html):
+    return {name for name, _ in _form_pairs(html)}
+
+
+def _visible_names(html):
+    """Names of controls a user can see (anything but type=hidden)."""
+    names = set()
+    for tag in re.findall(r"<(?:input|select|textarea)\b[^>]*>", html):
+        m = re.search(r'\bname="([^"]+)"', tag)
+        if m and 'type="hidden"' not in tag:
+            names.add(m.group(1))
+    return names
+
+
+def _make_post(tmp_path, schema, stored, plugin_id="demo"):
+    from src.plugin_system.schema_manager import SchemaManager
+    from web_interface.blueprints import api_v3 as a
+
+    originals = {k: getattr(a.api_v3, k, None)
+                 for k in ("config_manager", "schema_manager", "plugin_manager")}
+
+    pdir = tmp_path / "plugins" / plugin_id
+    pdir.mkdir(parents=True)
+    (pdir / "config_schema.json").write_text(json.dumps(schema), encoding="utf-8")
+
+    store = {plugin_id: json.loads(json.dumps(stored))}
+    cm = MagicMock()
+    cm.load_config.side_effect = lambda: json.loads(json.dumps(store))
+    cm.get_raw_file_content.return_value = {}
+    cm.get_config_path.return_value = str(tmp_path / "config.json")
+
+    def _save(cfg, **_kw):
+        store.clear()
+        store.update(cfg)
+        return type("R", (), {"status": type("S", (), {"value": "success"})(),
+                              "message": None})()
+
+    cm.save_config_atomic.side_effect = _save
+
+    a.api_v3.config_manager = cm
+    a.api_v3.schema_manager = SchemaManager(plugins_dir=tmp_path / "plugins",
+                                            project_root=tmp_path)
+    pm = MagicMock()
+    pm.plugins = {}
+    pm.get_plugin.return_value = None
+    a.api_v3.plugin_manager = pm
+
+    app = Flask(__name__)
+    app.config["TESTING"] = True
+    app.register_blueprint(a.api_v3, url_prefix="/api/v3")
+    client = app.test_client()
+
+    def _post(pairs):
+        resp = client.post(f"/api/v3/plugins/config?plugin_id={plugin_id}",
+                           data=MultiDict(pairs))
+        return resp, store.get(plugin_id, {})
+
+    def _post_json(config):
+        resp = client.post("/api/v3/plugins/config",
+                           json={"plugin_id": plugin_id, "config": config})
+        return resp, store.get(plugin_id, {})
+
+    def _restore():
+        for k, v in originals.items():
+            setattr(a.api_v3, k, v)
+
+    return _post, _post_json, _restore
+
+
+@pytest.fixture
+def post(tmp_path):
+    _post, _post_json, restore = _make_post(tmp_path, SCHEMA, STORED)
+    _post.json = _post_json
+    try:
+        yield _post
+    finally:
+        restore()
+
+
+# --------------------------------------------------------------------------
+# Rendering
+# --------------------------------------------------------------------------
+
+class TestRendering:
+    html = None
+
+    @classmethod
+    def setup_class(cls):
+        cls.html = _render(SCHEMA, STORED)
+
+    def test_no_hidden_field_gets_a_visible_control(self):
+        visible = _visible_names(self.html)
+        for name in ("legacy_key", "legacy_flag", "old_zoom",
+                     "display.old_flag", "display.old_mode",
+                     "internal.token_seen", "internal.revision"):
+            assert name not in visible, name
+        assert not [n for n in visible if re.fullmatch(
+            r"entries\.\d+\.(id|pinned|weight|layout\.legacy_x)", n)], visible
+
+    def test_plain_and_nested_hidden_fields_are_not_posted_at_all(self):
+        names = _names(self.html)
+        for name in ("legacy_key", "legacy_flag", "old_zoom",
+                     "display.old_flag", "display.old_mode",
+                     "internal.token_seen", "internal.revision"):
+            assert name not in names, name
+
+    def test_no_hidden_label_is_drawn(self):
+        for label in HIDDEN_LABELS:
+            assert f">{label}<" not in self.html, label
+            assert f"{label}\n" not in self.html, label
+
+    def test_visible_siblings_still_render(self):
+        visible = _visible_names(self.html)
+        assert {"city", "timeout", "display.show_clock",
+                "entries.0.name", "entries.0.enabled"} <= visible
+
+    def test_rendered_sections_exclude_hidden_top_level_keys(self):
+        sections = re.findall(r'name="__rendered_section" value="([^"]+)"',
+                              self.html)
+        assert set(sections) == {"city", "timeout", "display", "entries"}
+
+    def test_an_object_of_only_hidden_children_draws_no_section(self):
+        assert "Internal Stuff" not in self.html
+        assert "section-internal" not in self.html
+
+    def test_the_advanced_count_excludes_hidden_fields(self):
+        assert re.findall(r"Advanced Settings \((\d+)\)", self.html) == ["1"]
+
+    def test_advanced_settings_disappear_when_all_advanced_are_hidden(self):
+        schema = json.loads(json.dumps(SCHEMA))
+        del schema["properties"]["timeout"]
+        html = _render(schema, STORED)
+        assert "Advanced Settings" not in html
+
+    def test_hidden_array_properties_are_not_columns(self):
+        headers = re.findall(r"<th[^>]*>([^<]+)</th>", self.html)
+        assert "Row ID" not in headers and "Pinned" not in headers
+        cols = re.search(r"data-display-columns='([^']*)'", self.html)
+        assert json.loads(cols.group(1)) == ["enabled", "name"]
+
+    def test_hidden_array_properties_stay_out_of_the_row_editor(self):
+        """The editor draws a field for every data-nested-prop and every key
+        of the advanced cell's data-prop-schema."""
+        assert 'data-nested-prop="pinned"' not in self.html
+        assert 'data-nested-prop="layout.legacy_x"' not in self.html
+        assert 'data-nested-prop="layout.x"' in self.html
+        for m in re.finditer(r"class=\"array-table-advanced-data\"\s+"
+                             r"data-prop-schema='([^']*)'", self.html):
+            import html as _h
+            adv = json.loads(_h.unescape(m.group(1)))
+            assert "pinned" not in adv and "weight" not in adv and "id" not in adv
+
+    def test_stored_hidden_row_values_are_carried_json_encoded(self):
+        pairs = dict(_form_pairs(self.html))
+        assert pairs["entries.0.id"] == '"1"'
+        assert pairs["entries.0.pinned"] == "true"
+        assert pairs["entries.0.weight"] == "2.5"
+        assert pairs["entries.0.layout.legacy_x"] == "9"
+        assert pairs["entries.1.id"] == '"cd_ab12cd34ef56"'
+        # Absent stored values are not invented.
+        assert "entries.1.weight" not in pairs
+        assert "entries.1.layout.legacy_x" not in pairs
+
+
+def test_a_schema_without_the_flag_renders_as_before():
+    """Regression guard: the flag's absence changes nothing."""
+    schema = json.loads(json.dumps(SCHEMA))
+
+    def strip(node):
+        if isinstance(node, dict):
+            node.pop("x-display", None)
+            for v in node.values():
+                strip(v)
+    strip(schema)
+    html = _render(schema, STORED)
+    visible = _visible_names(html)
+    assert {"legacy_key", "legacy_flag", "old_zoom", "display.old_flag",
+            "internal.token_seen", "entries.0.id"} <= visible
+    # Not a column, so it lives in the row editor's advanced cell as before.
+    assert 'data-nested-prop="pinned"' in html
+    assert re.findall(r"Advanced Settings \((\d+)\)", html) == ["2"]
+
+
+# --------------------------------------------------------------------------
+# Saving
+# --------------------------------------------------------------------------
+
+class TestSavingTheRenderedForm:
+    def test_the_untouched_form_changes_no_hidden_value(self, post):
+        resp, cfg = post(_form_pairs(_render(SCHEMA, STORED)))
+        assert resp.status_code == 200, resp.get_json()
+        assert cfg["legacy_key"] == "keep-me"
+        assert cfg["legacy_flag"] is True
+        assert cfg["old_zoom"] == 5
+        assert cfg["display"]["old_flag"] is True
+        assert cfg["display"]["old_mode"] == "classic"
+        assert cfg["internal"] == {"token_seen": True, "revision": 7}
+        first, second = cfg["entries"]
+        assert first["id"] == "1" and isinstance(first["id"], str)
+        assert first["pinned"] is True
+        assert first["weight"] == 2.5
+        assert first["layout"]["legacy_x"] == 9
+        assert second["id"] == "cd_ab12cd34ef56"
+        assert second["pinned"] is False
+
+    def test_visible_edits_apply_and_an_unchecked_visible_box_is_cleared(self, post):
+        pairs = [(k, v) for k, v in _form_pairs(_render(SCHEMA, STORED))
+                 if k != "display.show_clock"]
+        pairs = [(k, "Austin" if k == "city" else v) for k, v in pairs]
+        resp, cfg = post(pairs)
+        assert resp.status_code == 200, resp.get_json()
+        assert cfg["city"] == "Austin"
+        # The existing unchecked-checkbox behaviour, in the same section as
+        # hidden booleans that must not be touched.
+        assert cfg["display"]["show_clock"] is False
+        assert cfg["display"]["old_flag"] is True
+        assert cfg["legacy_flag"] is True
+        assert cfg["entries"][0]["pinned"] is True
+
+    def test_a_deleted_row_takes_its_hidden_values_with_it(self, post):
+        """Row 0 removed; the browser renumbers row 1 to index 0."""
+        pairs = []
+        for k, v in _form_pairs(_render(SCHEMA, STORED)):
+            m = re.match(r"entries\.(\d+)\.(.*)", k)
+            if m:
+                if m.group(1) == "0":
+                    continue
+                k = f"entries.0.{m.group(2)}"
+            pairs.append((k, v))
+        resp, cfg = post(pairs)
+        assert resp.status_code == 200, resp.get_json()
+        assert [e["id"] for e in cfg["entries"]] == ["cd_ab12cd34ef56"]
+
+    def test_a_new_row_gets_no_invented_hidden_values(self, post):
+        pairs = _form_pairs(_render(SCHEMA, STORED)) + [
+            ("entries.2.enabled", "true"), ("entries.2.name", "Third")]
+        resp, cfg = post(pairs)
+        assert resp.status_code == 200, resp.get_json()
+        assert cfg["entries"][2]["name"] == "Third"
+        assert "id" not in cfg["entries"][2]
+        assert "pinned" not in cfg["entries"][2]
+
+    def test_a_json_api_save_still_writes_hidden_fields(self, post):
+        """Hidden is a form concern: API callers can still set these."""
+        config = json.loads(json.dumps(STORED))
+        config["legacy_flag"] = False
+        config["display"]["old_mode"] = "modern"
+        config["entries"][0]["id"] = "renamed"
+        resp, cfg = post.json(config)
+        assert resp.status_code == 200, resp.get_json()
+        assert cfg["legacy_flag"] is False
+        assert cfg["display"]["old_mode"] == "modern"
+        assert cfg["entries"][0]["id"] == "renamed"
+
+
+class TestMissingBooleans:
+    """_set_missing_booleans_to_false, directly, at every depth."""
+
+    def test_hidden_booleans_are_out_of_scope_everywhere(self):
+        from web_interface.blueprints.api_v3 import _set_missing_booleans_to_false
+
+        cfg = json.loads(json.dumps(STORED))
+        form_keys = {"city", "entries.0.name", "entries.1.name"}
+        _set_missing_booleans_to_false(
+            cfg, SCHEMA["properties"], form_keys,
+            sections={"city", "display", "entries", "internal", "legacy_flag"})
+
+        assert cfg["legacy_flag"] is True
+        assert cfg["display"]["old_flag"] is True
+        assert cfg["internal"]["token_seen"] is True
+        assert cfg["entries"][0]["pinned"] is True
+        # Visible booleans in the same places are still cleared.
+        assert cfg["display"]["show_clock"] is False
+        assert cfg["entries"][0]["enabled"] is False
+
+    def test_hidden_array_item_property_lookup(self):
+        from web_interface.blueprints.api_v3 import _hidden_array_item_property
+
+        assert _hidden_array_item_property(SCHEMA, "entries.0.id")
+        assert _hidden_array_item_property(SCHEMA, "entries.12.layout.legacy_x")
+        assert _hidden_array_item_property(SCHEMA, "entries.0.name") is None
+        assert _hidden_array_item_property(SCHEMA, "entries.0.layout.x") is None
+        # Only array rows qualify: plain hidden keys are never posted.
+        assert _hidden_array_item_property(SCHEMA, "legacy_key") is None
+        assert _hidden_array_item_property(SCHEMA, "display.old_flag") is None
+
+
+# --------------------------------------------------------------------------
+# Real plugin schemas (snippets copied from ledmatrix-plugins)
+# --------------------------------------------------------------------------
+
+# plugins/countdown/config_schema.json, trimmed to the countdowns table.
+COUNTDOWN_SCHEMA = {
+    "type": "object",
+    "properties": {
+        "enabled": {"type": "boolean", "default": True},
+        "countdowns": {
+            "type": "array",
+            "x-widget": "array-table",
+            "x-columns": ["enabled", "name", "target_date", "target_time", "mode"],
+            "default": [],
+            "items": {
+                "type": "object",
+                "properties": {
+                    "id": {"type": "string", "title": "ID",
+                           "description": "Unique identifier (auto-generated)",
+                           "x-display": "hidden"},
+                    "enabled": {"type": "boolean", "title": "Enabled", "default": True},
+                    "name": {"type": "string", "title": "Name",
+                             "minLength": 1, "maxLength": 30},
+                    "target_date": {"type": "string", "title": "Target Date",
+                                    "x-widget": "date-picker",
+                                    "pattern": "^\\d{4}-\\d{2}-\\d{2}$"},
+                    "target_time": {"type": "string", "title": "Target Time",
+                                    "x-widget": "time-picker", "default": "00:00"},
+                    "mode": {"type": "string", "title": "Mode",
+                             "enum": ["until", "since"], "default": "until"},
+                    "display_order": {"x-advanced": True, "type": "integer",
+                                      "title": "Order", "default": 0, "minimum": 0},
+                },
+                "required": ["name", "target_date"],
+            },
+        },
+        "show_expired": {"x-advanced": True, "type": "boolean",
+                         "title": "Show Expired", "default": False},
+    },
+    "required": ["enabled"],
+}
+
+COUNTDOWN_STORED = {
+    "enabled": True,
+    "show_expired": True,
+    "countdowns": [
+        {"id": "cd_0123456789ab", "enabled": True, "name": "Vacation",
+         "target_date": "2026-12-20", "target_time": "00:00", "mode": "until",
+         "display_order": 0},
+        {"id": "42", "enabled": True, "name": "Anniversary",
+         "target_date": "2020-06-01", "target_time": "00:00", "mode": "since",
+         "display_order": 1},
+    ],
+}
+
+# plugins/ledmatrix-weather/config_schema.json, trimmed.
+WEATHER_SCHEMA = {
+    "type": "object",
+    "properties": {
+        "enabled": {"type": "boolean", "default": False},
+        "location_city": {"type": "string", "default": "Dallas", "title": "City"},
+        "update_interval": {"x-advanced": True, "type": "integer", "default": 1800,
+                            "minimum": 300},
+        "api_key": {"x-advanced": True, "x-display": "hidden", "type": "string",
+                    "title": "API Key (deprecated)"},
+        "radar_range_miles": {"type": "integer", "default": 75, "minimum": 10,
+                              "maximum": 500, "title": "Radar Range (miles)"},
+        "radar_zoom": {"x-advanced": True, "x-display": "hidden", "type": "integer",
+                       "default": 6, "minimum": 4, "maximum": 8,
+                       "title": "Radar Zoom Level (deprecated)"},
+        "radar_show_nowcast": {"type": "boolean", "default": True,
+                               "title": "Show Forecast Frames"},
+    },
+}
+
+WEATHER_STORED = {"enabled": True, "location_city": "Tampa", "update_interval": 900,
+                  "api_key": "legacy-owm-key", "radar_range_miles": 75,
+                  "radar_zoom": 7, "radar_show_nowcast": True}
+
+
+def test_countdown_ids_survive_a_form_save(tmp_path):
+    html = _render(COUNTDOWN_SCHEMA, COUNTDOWN_STORED, "countdown")
+    assert ">ID<" not in html
+    assert "countdowns.0.id" not in _visible_names(html)
+
+    _post, _json, restore = _make_post(tmp_path, COUNTDOWN_SCHEMA,
+                                       COUNTDOWN_STORED, "countdown")
+    try:
+        # Edit a visible cell too.
+        pairs = [(k, "Beach" if k == "countdowns.0.name" else v)
+                 for k, v in _form_pairs(html)]
+        resp, cfg = _post(pairs)
+    finally:
+        restore()
+    assert resp.status_code == 200, resp.get_json()
+    assert [c["id"] for c in cfg["countdowns"]] == ["cd_0123456789ab", "42"]
+    assert cfg["countdowns"][0]["name"] == "Beach"
+
+
+def test_weather_deprecated_keys_are_hidden_and_kept(tmp_path):
+    html = _render(WEATHER_SCHEMA, WEATHER_STORED, "weather")
+    assert "api_key" not in html and "radar_zoom" not in html
+    assert "Radar Zoom Level" not in html and "API Key" not in html
+    assert re.findall(r"Advanced Settings \((\d+)\)", html) == ["1"]
+    assert "radar_range_miles" in _visible_names(html)
+
+    _post, _json, restore = _make_post(tmp_path, WEATHER_SCHEMA,
+                                       WEATHER_STORED, "weather")
+    try:
+        pairs = [(k, v) for k, v in _form_pairs(html)
+                 if k != "radar_show_nowcast"]
+        resp, cfg = _post(pairs)
+    finally:
+        restore()
+    assert resp.status_code == 200, resp.get_json()
+    assert cfg["api_key"] == "legacy-owm-key"
+    assert cfg["radar_zoom"] == 7
+    assert cfg["radar_show_nowcast"] is False

web_interface/blueprints/api_v3/__init__.py

@@ -1039,6 +1039,51 @@ def _set_nested_value(config, key_path, value):
 _RENDERED_SECTION_FIELD = '__rendered_section'
 
 
+def _is_hidden_prop(prop_schema):
+    """Whether a schema property is declared ``"x-display": "hidden"``.
+
+    Mirrors ``prop_is_hidden`` in ``plugin_config.html``: an object whose every
+    child is hidden counts as hidden too. A hidden property stays declared (so
+    stored configs carrying it keep validating) but the form draws no control
+    for it, which puts it outside everything the save infers from the form.
+    """
+    if not isinstance(prop_schema, dict):
+        return False
+    if prop_schema.get('x-display') == 'hidden':
+        return True
+    children = prop_schema.get('properties')
+    if isinstance(children, dict) and children:
+        return all(_is_hidden_prop(child) for child in children.values())
+    return False
+
+
+def _hidden_array_item_property(schema, key_path):
+    """The hidden schema property a posted array-row key names, else None.
+
+    Only paths through an array index (``countdowns.0.id``) qualify: that is
+    the one place the rendered form posts a hidden value, because a posted row
+    replaces the stored item wholesale. The value is JSON-encoded there so its
+    exact type survives the round trip.
+    """
+    parts = key_path.split('.')
+    digit_at = next((i for i, p in enumerate(parts) if p.isdigit()), None)
+    if digit_at is None or digit_at == 0 or digit_at == len(parts) - 1:
+        return None
+    array_prop = _get_schema_property(schema, '.'.join(parts[:digit_at]))
+    if not _schema_type_is(array_prop, 'array'):
+        return None
+    items = array_prop.get('items')
+    if not isinstance(items, dict) or not isinstance(items.get('properties'), dict):
+        return None
+    rest = '.'.join(parts[digit_at + 1:])
+    item_schema = {'properties': items['properties']}
+    prop = _get_schema_property(item_schema, rest)
+    if prop is None:
+        # Deeper array inside the item (rare): keep walking.
+        return _hidden_array_item_property(item_schema, rest)
+    return prop if _is_hidden_prop(prop) else None
+
+
 def _boolean_is_in_scope(full_path, prefix, sections, submitted_parents):
     """Whether a missing checkbox at ``full_path`` may be forced to False.
 
@@ -1112,6 +1157,12 @@ def _set_missing_booleans_to_false(plugin_config, schema_props, form_keys, prefi
         if not isinstance(prop_schema, dict):
             continue
 
+        # A hidden property (or an object of nothing but hidden ones) was never
+        # drawn, so its absence from the form is not an unchecked box. Leave it
+        # -- and everything under it -- exactly as stored.
+        if _is_hidden_prop(prop_schema):
+            continue
+
         full_path = f"{prefix}.{prop_name}" if prefix else prop_name
         prop_type = prop_schema.get('type')
 

web_interface/blueprints/api_v3/config.py

@@ -555,15 +555,6 @@ def save_main_config():
             if 'panel_type' in data and data['panel_type'] not in PANEL_TYPE_ALLOWED:
                 return jsonify({'status': 'error', 'message': f"Invalid panel type '{data['panel_type']}'. Allowed values: Standard (empty), FM6126A, FM6127"}), 400
 
-            # Validate multiplexing
-            if 'multiplexing' in data:
-                try:
-                    mux_val = int(data['multiplexing'])
-                    if mux_val < 0 or mux_val > 22:
-                        return jsonify({'status': 'error', 'message': f"Invalid multiplexing value '{data['multiplexing']}'. Must be an integer from 0 to 22."}), 400
-                except (ValueError, TypeError, OverflowError):
-                    return jsonify({'status': 'error', 'message': f"Invalid multiplexing value '{data['multiplexing']}'. Must be an integer from 0 to 22."}), 400
-
             # Validate pixel_mapper_config (free-form mapper string, e.g. "U-mapper;Rotate:90")
             if 'pixel_mapper_config' in data and not isinstance(data['pixel_mapper_config'], str):
                 return jsonify({'status': 'error', 'message': 'pixel_mapper_config must be a string (e.g. "U-mapper;Rotate:90" or empty)'}), 400
@@ -573,14 +564,47 @@ def save_main_config():
             if 'orientation' in data and data['orientation'] not in ORIENTATION_ALLOWED:
                 return jsonify({'status': 'error', 'message': f"Invalid orientation '{data['orientation']}'. Allowed values: {', '.join(sorted(ORIENTATION_ALLOWED))}"}), 400
 
-            # Validate row_address_type
+            # Panel geometry, PWM and GPIO timing, held to what the rgbmatrix library
-            if 'row_address_type' in data:
+            # accepts (RGBMatrix::Options::Validate in lib/options-initialize.cc,
+            # the gpio_slowdown check in lib/led-matrix.cc). Outside those ranges
+            # the config used to save, then the matrix refused to start and the
+            # display dropped to fallback mode. cols, chain_length and
+            # limit_refresh_rate_hz (0 = no cap) have no upper bound in the
+            # library. rows has none here by choice: the library currently
+            # rejects more than 64 per panel, and that limit is left to it so a
+            # library that lifts it needs no change here.
+            def _hardware_int_error(field, low, high=None, even=False):
+                """A 400 response if data[field] is not an allowed integer, else None."""
+                raw = data[field]
+                kind = "an even integer" if even else "an integer"
+                if high is None:
+                    allowed = f"{kind} of at least {low}"
+                else:
+                    allowed = f"{kind} from {low} to {high}"
+                rejection = (jsonify({'status': 'error', 'message': f"Invalid {field} '{raw}'. Must be {allowed}."}), 400)
+                # int() would quietly turn true into 1 and 48.5 into 48.
+                if isinstance(raw, bool) or (isinstance(raw, float) and not raw.is_integer()):
+                    return rejection
                 try:
-                    rat_val = int(data['row_address_type'])
+                    value = int(raw)
-                    if rat_val < 0 or rat_val > 4:
-                        return jsonify({'status': 'error', 'message': f"Invalid row_address_type '{data['row_address_type']}'. Must be an integer from 0 to 4."}), 400
                 except (ValueError, TypeError, OverflowError):
-                    return jsonify({'status': 'error', 'message': f"Invalid row_address_type '{data['row_address_type']}'. Must be an integer from 0 to 4."}), 400
+                    return rejection
+                if value < low or (high is not None and value > high) or (even and value % 2):
+                    return rejection
+                return None
+
+            for field, low, high, even in (('rows', 8, None, True), ('cols', 16, None, False),
+                                           ('chain_length', 1, None, False), ('parallel', 1, 3, False),
+                                           ('brightness', 1, 100, False), ('scan_mode', 0, 1, False),
+                                           ('pwm_bits', 1, 11, False), ('pwm_dither_bits', 0, 2, False),
+                                           ('pwm_lsb_nanoseconds', 50, 3000, False),
+                                           ('limit_refresh_rate_hz', 0, None, False),
+                                           ('row_address_type', 0, 5, False), ('multiplexing', 0, 22, False),
+                                           ('gpio_slowdown', 0, 10, False)):
+                if field in data:
+                    error = _hardware_int_error(field, low, high, even)
+                    if error:
+                        return error
 
             # Handle hardware settings
             for field in ['rows', 'cols', 'chain_length', 'parallel', 'brightness', 'hardware_mapping', 'scan_mode',

web_interface/blueprints/api_v3/plugins.py

@@ -8,7 +8,7 @@ from web_interface.blueprints.api_v3 import (
     _CALENDAR_LIST_MAX_PAGES, _RENDERED_SECTION_FIELD, _SKIP_FIELD, _coerce_to_bool,
     _do_transactional_uninstall, _enhance_schema_with_core_properties,
     _filter_config_by_schema, _get_plugin_version, _get_schema_property,
-    _installed_plugin_ids, _is_plugin_update_available,
+    _hidden_array_item_property, _installed_plugin_ids, _is_plugin_update_available,
     _parse_form_value_with_schema, _prune_credential_backups,
     _run_calendar_registration, _schema_allows_null, _schema_type_is,
     _set_missing_booleans_to_false,
@@ -1848,6 +1848,20 @@ def save_plugin_config():
                     # (to avoid overwriting the combined array with a single value)
                     if key not in indexed_base_paths:
                         # Parse value using schema to determine correct type
+                        parsed_value = _SKIP_FIELD
+                        decoded = False
+                        # A hidden property inside an array row is carried
+                        # through the form JSON-encoded (a posted row replaces
+                        # the stored item, so it must be posted at all). Decode
+                        # it exactly: the generic parse would turn an id "1"
+                        # into the integer 1 and fail validation.
+                        if _hidden_array_item_property(schema, key) is not None:
+                            try:
+                                parsed_value = json.loads(value)
+                                decoded = True
+                            except (TypeError, ValueError):
+                                pass
+                        if not decoded:
                             parsed_value = _parse_form_value_with_schema(value, key, schema)
                         # Debug logging for array fields
                         if schema:

web_interface/static/v3/js/widgets/array-table.js

@@ -111,6 +111,37 @@
 
     // ─── Helpers ────────────────────────────────────────────────────────────
 
+    /**
+     * "x-display": "hidden" — the property stays in the schema but gets no
+     * control. An object whose every child is hidden counts as hidden too.
+     * Mirrors prop_is_hidden in plugin_config.html and _is_hidden_prop on the
+     * server.
+     */
+    function isHiddenProp(schema) {
+        if (!schema || typeof schema !== 'object') return false;
+        if (schema['x-display'] === 'hidden') return true;
+        const children = schema.properties;
+        if (children && typeof children === 'object') {
+            const values = Object.values(children);
+            return values.length > 0 && values.every(isHiddenProp);
+        }
+        return false;
+    }
+
+    /**
+     * A hidden input carrying a hidden property's stored value, JSON-encoded so
+     * the save restores its exact type. A posted row replaces the stored item,
+     * so a value that isn't posted is lost.
+     */
+    function hiddenValueInput(name, dataKey, value) {
+        const input = document.createElement('input');
+        input.type  = 'hidden';
+        input.name  = name;
+        input.value = JSON.stringify(value);
+        input.dataset.hiddenProp = dataKey;
+        return input;
+    }
+
     function safeSetHTML(target, html) {
         target.textContent = '';
         // createContextualFragment parses html relative to the document context
@@ -343,6 +374,16 @@
             if (propType === 'object' && propSchema.properties) {
                 const nestedVal = (item && item[propName]) || {};
                 Object.entries(propSchema.properties).forEach(([subName, subSchema]) => {
+                    if (isHiddenProp(subSchema)) {
+                        // No data-nested-prop, so the row editor never shows it.
+                        const stored = Object.entries(nestedVal).find(([name]) => name === subName);
+                        if (stored && stored[1] !== undefined && stored[1] !== null) {
+                            cell.appendChild(hiddenValueInput(
+                                `${fullKey}.${index}.${propName}.${subName}`,
+                                `${propName}.${subName}`, stored[1]));
+                        }
+                        return;
+                    }
                     const subType = Array.isArray(subSchema.type)
                         ? subSchema.type.find(t => t !== 'null') || 'string'
                         : (subSchema.type || 'string');
@@ -386,7 +427,16 @@
         row.className = 'array-table-row';
         row.setAttribute('data-index', index);
 
+        // "x-display": "hidden" item properties: never a column (even if
+        // x-columns names one), never in the advanced cell or row editor.
+        const hiddenKeys = new Set(
+            Object.entries(fullItemProperties)
+                .filter(([, propSchema]) => isHiddenProp(propSchema))
+                .map(([propName]) => propName)
+        );
+
         // Visible column cells
+        displayColumns = displayColumns.filter(colName => !hiddenKeys.has(colName));
         displayColumns.forEach(colName => {
             const colDef   = itemProperties[colName] || {};
             const colType  = Array.isArray(colDef.type) ? colDef.type.find(t => t !== 'null') || 'string' : (colDef.type || 'string');
@@ -396,10 +446,11 @@
             row.appendChild(createCell(fullKey, index, colName, colDef, colValue, pluginId));
         });
 
-        // Determine non-displayed properties (these go into the advanced cell + edit modal)
+        // Determine non-displayed properties (these go into the advanced cell + edit modal).
+        // Hidden ones ("x-display": "hidden") get no column and no editor field.
         const nonDisplayed = {};
         Object.keys(fullItemProperties).forEach(k => {
-            if (!displayColumns.includes(k) && k !== 'id') {
+            if (!displayColumns.includes(k) && k !== 'id' && !hiddenKeys.has(k)) {
                 nonDisplayed[k] = fullItemProperties[k];
             }
         });
@@ -430,6 +481,14 @@
             actionsCell.appendChild(editBtn);
         }
 
+        // Hidden properties: carry stored values only. A new row has none, so
+        // nothing is invented (countdown fills in its own id).
+        Object.entries(item).forEach(([propName, stored]) => {
+            if (hiddenKeys.has(propName) && stored !== undefined && stored !== null) {
+                actionsCell.appendChild(hiddenValueInput(`${fullKey}.${index}.${propName}`, propName, stored));
+            }
+        });
+
         row.appendChild(actionsCell);
 
         // Hidden advanced data cell
@@ -494,6 +553,7 @@
                 grid.className = 'grid grid-cols-2 gap-3';
 
                 Object.entries(propSchema.properties).forEach(([subName, subSchema]) => {
+                    if (isHiddenProp(subSchema)) return;
                     const subType    =Array.isArray(subSchema.type) ? subSchema.type.find(t => t !== 'null') || 'string' : (subSchema.type || 'string');
                     const subLabel   = subSchema.title || subName.replace(/_/g, ' ').replace(/\b\w/g, c => c.toUpperCase());
                     const subDesc    = subSchema.description || '';

web_interface/static/v3/plugins_manager.js

@@ -2409,6 +2409,19 @@ function getSchemaProperty(schema, path) {
     return null;
 }
 
+// "x-display": "hidden" (or an object of nothing but hidden children).
+// Mirrors prop_is_hidden in plugin_config.html.
+function isHiddenSchemaProp(schema) {
+    if (!schema || typeof schema !== 'object') return false;
+    if (schema['x-display'] === 'hidden') return true;
+    const children = schema.properties;
+    if (children && typeof children === 'object') {
+        const values = Object.values(children);
+        return values.length > 0 && values.every(isHiddenSchemaProp);
+    }
+    return false;
+}
+
 // Helper function to render a single item in an array of objects
 function renderArrayObjectItem(fieldId, fullKey, itemProperties, itemValue, index, itemsSchema) {
     const item = itemValue || {};
@@ -2422,6 +2435,9 @@ function renderArrayObjectItem(fieldId, fullKey, itemProperties, itemValue, inde
     const propertyOrder = itemsSchema['x-propertyOrder'] || Object.keys(itemProperties);
     propertyOrder.forEach(propKey => {
         if (!itemProperties[propKey]) return;
+        // "x-display": "hidden": no control. The stored value survives through
+        // data-item-data, which updateArrayObjectData overlays edits onto.
+        if (isHiddenSchemaProp(itemProperties[propKey])) return;
 
         const propSchema = itemProperties[propKey];
         const propValue = item[propKey] !== undefined ? item[propKey] : propSchema.default;
@@ -5478,6 +5494,7 @@ if (typeof window !== 'undefined') {
             itemHtml = `<div class="border border-gray-300 rounded-lg p-4 bg-gray-50 array-object-item" data-index="${newIndex}">`;
             Object.keys(itemsSchema.properties || {}).forEach(propKey => {
                 const propSchema = itemsSchema.properties[propKey];
+                if (propSchema && propSchema['x-display'] === 'hidden') return;
                 const propValue = newItem[propKey] !== undefined ? newItem[propKey] : propSchema.default;
                 const propLabel = propSchema.title || propKey.replace(/_/g, ' ').replace(/\b\w/g, l => l.toUpperCase());
                 itemHtml += `<div class="mb-3"><label class="block text-sm font-medium text-gray-700 mb-1">${escapeHtml(propLabel)}</label>`;

web_interface/templates/v3/partials/display.html

@@ -41,46 +41,44 @@
 
             <div class="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-4 xl:grid-cols-4 2xl:grid-cols-4 gap-4 mb-4">
                 <div class="form-group" id="setting-display-rows" data-setting-key="display.hardware.rows">
-                    <label for="rows" class="block text-sm font-medium text-gray-700">Rows{{ ui.help_tip('Number of LED rows on a single panel.\nCommon: 16, 32, or 64. Default: 32. Must match your panel.', 'Rows') }}</label>
+                    <label for="rows" class="block text-sm font-medium text-gray-700">Rows{{ ui.help_tip('Number of LED rows on a single panel.\nCommon: 16, 32, 48 or 64. Default: 32. Must match your panel and be an even number, at least 8. There is no upper limit here, but the current rgbmatrix library rejects more than 64 rows per panel, and the display will not start.', 'Rows') }}</label>
                     <input type="number"
                            id="rows"
                            name="rows"
                            value="{{ main_config.display.hardware.rows or 32 }}"
-                           min="1"
+                           min="8"
-                           max="128"
+                           step="2"
                            class="form-control">
                 </div>
 
                 <div class="form-group" id="setting-display-cols" data-setting-key="display.hardware.cols">
-                    <label for="cols" class="block text-sm font-medium text-gray-700">Columns{{ ui.help_tip('Number of LED columns on a single panel.\nCommon: 32 or 64. Default: 64. Must match your panel.', 'Columns') }}</label>
+                    <label for="cols" class="block text-sm font-medium text-gray-700">Columns{{ ui.help_tip('Number of LED columns on a single panel.\nCommon: 32, 64, 96 or 128. Default: 64. Must match your panel. At least 16, with no upper limit.', 'Columns') }}</label>
                     <input type="number"
                            id="cols"
                            name="cols"
                            value="{{ main_config.display.hardware.cols or 64 }}"
-                           min="1"
+                           min="16"
-                           max="128"
                            class="form-control">
                 </div>
 
                 <div class="form-group" id="setting-display-chain_length" data-setting-key="display.hardware.chain_length">
-                    <label for="chain_length" class="block text-sm font-medium text-gray-700">Chain Length{{ ui.help_tip('How many panels are wired end-to-end in one chain.\nDefault: 2. Example: two 64×32 panels chained make a 128×32 display.', 'Chain Length') }}</label>
+                    <label for="chain_length" class="block text-sm font-medium text-gray-700">Chain Length{{ ui.help_tip('How many panels are wired end-to-end in one chain.\nDefault: 2. Example: two 64×32 panels chained make a 128×32 display. No upper limit, but longer chains lower the refresh rate.', 'Chain Length') }}</label>
                     <input type="number"
                            id="chain_length"
                            name="chain_length"
                            value="{{ main_config.display.hardware.chain_length or 2 }}"
                            min="1"
-                           max="24"
                            class="form-control">
                 </div>
 
                 <div class="form-group" id="setting-display-parallel" data-setting-key="display.hardware.parallel">
-                    <label for="parallel" class="block text-sm font-medium text-gray-700">Parallel{{ ui.help_tip('Number of separate chains driven in parallel from the HAT.\nDefault: 1. The Raspberry Pi supports up to 3 (some HATs allow more).', 'Parallel') }}</label>
+                    <label for="parallel" class="block text-sm font-medium text-gray-700">Parallel{{ ui.help_tip('Number of separate chains driven in parallel from the HAT.\nDefault: 1. The Raspberry Pi supports up to 3, and the HAT needs that many outputs (e.g. the Adafruit Triple LED Matrix Bonnet).', 'Parallel') }}</label>
                     <input type="number"
                            id="parallel"
                            name="parallel"
                            value="{{ main_config.display.hardware.parallel or 1 }}"
                            min="1"
-                           max="4"
+                           max="3"
                            class="form-control">
                 </div>
             </div>
@@ -108,7 +106,7 @@
                 </div>
 
                 <div class="form-group" id="setting-display-hardware_mapping" data-setting-key="display.hardware.hardware_mapping">
-                    <label for="hardware_mapping" class="block text-sm font-medium text-gray-700">Hardware Mapping{{ ui.help_tip('How the LED panel is wired to the Pi.\nUse "Adafruit HAT PWM" for an Adafruit HAT/Bonnet with the PWM solder mod; "Adafruit HAT" without it; "Regular" for direct GPIO wiring.', 'Hardware Mapping') }}</label>
+                    <label for="hardware_mapping" class="block text-sm font-medium text-gray-700">Hardware Mapping{{ ui.help_tip('How the LED panel is wired to the Pi.\nUse "Adafruit HAT PWM" for an Adafruit RGB Matrix HAT/Bonnet with the PWM solder mod; "Adafruit HAT" without it (no hardware pulsing, so expect a little more flicker); "Regular" for direct GPIO wiring and for the Adafruit Triple LED Matrix Bonnet.', 'Hardware Mapping') }}</label>
                     <select id="hardware_mapping" name="hardware_mapping" class="form-control">
                         <option value="adafruit-hat-pwm" {% if main_config.display.hardware.hardware_mapping == "adafruit-hat-pwm" %}selected{% endif %}>Adafruit HAT PWM</option>
                         <option value="adafruit-hat" {% if main_config.display.hardware.hardware_mapping == "adafruit-hat" %}selected{% endif %}>Adafruit HAT</option>
@@ -126,7 +124,7 @@
                 </div>
 
                 <div class="form-group" id="setting-display-led_rgb_sequence" data-setting-key="display.hardware.led_rgb_sequence">
-                    <label for="led_rgb_sequence" class="block text-sm font-medium text-gray-700">LED RGB Sequence{{ ui.help_tip('Order the panel expects color channels in.\nChange this only if reds/greens/blues look swapped. Default: RGB.', 'LED RGB Sequence') }}</label>
+                    <label for="led_rgb_sequence" class="block text-sm font-medium text-gray-700">LED RGB Sequence{{ ui.help_tip('Order the panel expects color channels in.\nChange this only if reds/greens/blues look swapped (red shows as blue: try BGR). Default: RGB. The Waveshare 96x48 V2 needs BGR.', 'LED RGB Sequence') }}</label>
                     <select id="led_rgb_sequence" name="led_rgb_sequence" class="form-control">
                         <option value="RGB" {% if main_config.display.hardware.get('led_rgb_sequence', 'RGB') == "RGB" %}selected{% endif %}>RGB</option>
                         <option value="RBG" {% if main_config.display.hardware.get('led_rgb_sequence', 'RGB') == "RBG" %}selected{% endif %}>RBG</option>
@@ -160,7 +158,7 @@
 
             <div class="grid grid-cols-1 md:grid-cols-3 gap-4">
                 <div class="form-group" id="setting-display-multiplexing" data-setting-key="display.hardware.multiplexing">
-                    <label for="multiplexing" class="block text-sm font-medium text-gray-700">Multiplexing{{ ui.help_tip('Pixel-mapping scheme used by outdoor/specialty panels.\nLeave at 0 (Direct) for most indoor panels. Only change if the image is scrambled — try values until it looks right.', 'Multiplexing') }}</label>
+                    <label for="multiplexing" class="block text-sm font-medium text-gray-700">Multiplexing{{ ui.help_tip('How the pixels are wired on outdoor/specialty panels (P10, P8, P4 and P3 outdoor modules and similar), whose LEDs are not laid out in straight rows.\nLeave at 0 (Direct) for most indoor panels. If the image is scrambled in a repeating pattern, try the value named after your panel first, then the others.', 'Multiplexing') }}</label>
                     <select id="multiplexing" name="multiplexing" class="form-control">
                         <option value="0" {% if main_config.display.hardware.get('multiplexing', 0)|int == 0 %}selected{% endif %}>0 - Direct</option>
                         <option value="1" {% if main_config.display.hardware.get('multiplexing', 0)|int == 1 %}selected{% endif %}>1 - Stripe</option>
@@ -189,7 +187,7 @@
                 </div>
 
                 <div class="form-group" id="setting-display-panel_type" data-setting-key="display.hardware.panel_type">
-                    <label for="panel_type" class="block text-sm font-medium text-gray-700">Panel Type{{ ui.help_tip('Special initialization for panels with a specific driver chip (e.g. FM6126A, FM6127).\nLeave on Standard unless your panel stays blank or shows only the first pixel.', 'Panel Type') }}</label>
+                    <label for="panel_type" class="block text-sm font-medium text-gray-700">Panel Type{{ ui.help_tip('Special initialization for panels with a specific driver chip (e.g. FM6126A, FM6127).\nLeave on Standard unless your panel stays blank or shows only the first pixel. FM6124 / FM6124D / FM6124DJ panels need no initialization: use Standard.', 'Panel Type') }}</label>
                     <select id="panel_type" name="panel_type" class="form-control">
                         <option value="" {% if not main_config.display.hardware.get('panel_type', '') %}selected{% endif %}>Standard</option>
                         <option value="FM6126A" {% if main_config.display.hardware.get('panel_type', '') == "FM6126A" %}selected{% endif %}>FM6126A</option>
@@ -198,24 +196,25 @@
                 </div>
 
                 <div class="form-group" id="setting-display-row_address_type" data-setting-key="display.hardware.row_address_type">
-                    <label for="row_address_type" class="block text-sm font-medium text-gray-700">Row Address Type{{ ui.help_tip('Row addressing scheme used by the panel.\nLeave at 0 (Default) unless your panel needs AB/ABC addressing — a wrong value shows a garbled or shifted image.', 'Row Address Type') }}</label>
+                    <label for="row_address_type" class="block text-sm font-medium text-gray-700">Row Address Type{{ ui.help_tip('Row addressing scheme used by the panel.\nLeave at 0 (Default) unless your panel needs AB/ABC addressing — a wrong value shows a garbled or shifted image.\nABC panels (no E line, common on 128x64 FM6124 boards): try 3. Panels with SM5368 row drivers, such as the Waveshare 96x48 V2 (back silkscreen 24S-A1), need 5 with RGB sequence BGR. If rows then jump up and down, or the bottom row shows a copy of other rows, raise GPIO Slowdown (6–8 on a Pi 4). On a Raspberry Pi 5 the rgbmatrix library supports only 0 and 2.', 'Row Address Type') }}</label>
                     <select id="row_address_type" name="row_address_type" class="form-control">
                         <option value="0" {% if main_config.display.hardware.get('row_address_type', 0)|int == 0 %}selected{% endif %}>0 - Default</option>
                         <option value="1" {% if main_config.display.hardware.get('row_address_type', 0)|int == 1 %}selected{% endif %}>1 - AB-addressed panels</option>
                         <option value="2" {% if main_config.display.hardware.get('row_address_type', 0)|int == 2 %}selected{% endif %}>2 - Row direct</option>
                         <option value="3" {% if main_config.display.hardware.get('row_address_type', 0)|int == 3 %}selected{% endif %}>3 - ABC-addressed panels</option>
                         <option value="4" {% if main_config.display.hardware.get('row_address_type', 0)|int == 4 %}selected{% endif %}>4 - ABC Shift + DE direct</option>
+                        <option value="5" {% if main_config.display.hardware.get('row_address_type', 0)|int == 5 %}selected{% endif %}>5 - SM5368 / B707 row shift register</option>
                     </select>
                 </div>
             </div>
 
             <div class="grid grid-cols-1 md:grid-cols-3 gap-4">
                 <div class="form-group" id="setting-display-gpio_slowdown" data-setting-key="display.runtime.gpio_slowdown">
-                    <label for="gpio_slowdown" class="block text-sm font-medium text-gray-700">GPIO Slowdown{{ ui.help_tip('Slows the GPIO signal so the panel keeps up.\nGuide: Pi 3 → 1–2, Pi 4 → 2–4, Pi 5 (PIO) → 1–3. Increase if the display shows garbage or flicker; in RIO mode higher values may improve performance.', 'GPIO Slowdown') }}</label>
+                    <label for="gpio_slowdown" class="block text-sm font-medium text-gray-700">GPIO Slowdown{{ ui.help_tip('Slows GPIO writes so the panel electronics keep up (0–10); higher is more reliable but lowers the refresh rate.\nStarting points: Pi Zero / Pi 1 → 0–1, Pi 2 / Pi 3 → 1–3, Pi 4 → 2–4, Pi 5 (PIO) → 1–3. Panels on Row Address Type 5 (SM5368 row drivers) can need 6–8 on a Pi 4. Raise it if the display shows garbage, jumping rows or flicker; in RIO mode higher values may improve performance.', 'GPIO Slowdown') }}</label>
                     <input type="number"
                            id="gpio_slowdown"
                            name="gpio_slowdown"
-                           value="{{ main_config.display.runtime.gpio_slowdown or 3 }}"
+                           value="{{ main_config.display.get('runtime', {}).get('gpio_slowdown', 3) }}"
                            min="0"
                            max="10"
                            class="form-control">
@@ -223,7 +222,7 @@
 
                 <div class="form-group" id="setting-display-rp1_rio" data-setting-key="display.runtime.rp1_rio">
                     <label for="rp1_rio" class="block text-sm font-medium text-gray-700">
-                        RP1 Backend <span class="text-xs text-gray-400 font-normal">(Pi 5 only)</span>{{ ui.help_tip('Pi 5 RP1 coprocessor driver mode.\nPIO (0) is the default and uses less CPU. RIO (1) can push a higher refresh rate but inverts the GPIO Slowdown behavior. Ignored on Pi 3/4.', 'RP1 Backend') }}
+                        RP1 Backend <span class="text-xs text-gray-400 font-normal">(Pi 5 only)</span>{{ ui.help_tip('Pi 5 RP1 coprocessor driver mode.\nPIO (0) is the default and uses less CPU. RIO (1) can push a higher refresh rate but inverts the GPIO Slowdown behavior. Ignored on every other Pi model.', 'RP1 Backend') }}
                     </label>
                     <select id="rp1_rio" name="rp1_rio" class="form-control">
                         <option value="0" {% if main_config.display.get('runtime', {}).get('rp1_rio', 0)|int == 0 %}selected{% endif %}>0 &mdash; PIO (default, low CPU)</option>
@@ -232,7 +231,7 @@
                 </div>
 
                 <div class="form-group" id="setting-display-scan_mode" data-setting-key="display.hardware.scan_mode">
-                    <label for="scan_mode" class="block text-sm font-medium text-gray-700">Scan Mode{{ ui.help_tip('Order rows are refreshed in.\n0 = progressive (default), 1 = interlaced. Change only if you see banding or flicker on certain panels.', 'Scan Mode') }}</label>
+                    <label for="scan_mode" class="block text-sm font-medium text-gray-700">Scan Mode{{ ui.help_tip('Order rows are refreshed in.\n0 = progressive (default), 1 = interlaced. Interlaced can look a little smoother when the refresh rate is very low, but usually shows a comb effect on anything moving. Leave at 0 unless you are tuning a slow setup.', 'Scan Mode') }}</label>
                     <input type="number"
                            id="scan_mode"
                            name="scan_mode"
@@ -245,7 +244,7 @@
 
             <div class="grid grid-cols-1 md:grid-cols-2 gap-4">
                 <div class="form-group" id="setting-display-pwm_bits" data-setting-key="display.hardware.pwm_bits">
-                    <label for="pwm_bits" class="block text-sm font-medium text-gray-700">PWM Bits{{ ui.help_tip('Color depth per channel (1–11).\nHigher means smoother color but a lower refresh rate; lower means faster refresh with more banding. Default: 11 (this build defaults to 9).', 'PWM Bits') }}</label>
+                    <label for="pwm_bits" class="block text-sm font-medium text-gray-700">PWM Bits{{ ui.help_tip('Color depth per channel (1–11).\nHigher means smoother color but a lower refresh rate; lower drops the subtlest shades for a faster refresh (1 = 8 colors). Default: 9.', 'PWM Bits') }}</label>
                     <input type="number"
                            id="pwm_bits"
                            name="pwm_bits"
@@ -256,36 +255,36 @@
                 </div>
 
                 <div class="form-group" id="setting-display-pwm_dither_bits" data-setting-key="display.hardware.pwm_dither_bits">
-                    <label for="pwm_dither_bits" class="block text-sm font-medium text-gray-700">PWM Dither Bits{{ ui.help_tip('Time-dithering to gain apparent color depth (0–4).\nDefault: 0. Raising it can smooth gradients at the cost of a slightly lower refresh rate.', 'PWM Dither Bits') }}</label>
+                    <label for="pwm_dither_bits" class="block text-sm font-medium text-gray-700">PWM Dither Bits{{ ui.help_tip('Time-dithers the lowest color bits (0–2): their brightness comes from showing them on only some frames, which raises the refresh rate.\nDefault: 1. 0 gives the steadiest dim colors; 2 is fastest but dark shades can shimmer. The rgbmatrix library accepts only 0–2.', 'PWM Dither Bits') }}</label>
                     <input type="number"
                            id="pwm_dither_bits"
                            name="pwm_dither_bits"
-                           value="{{ main_config.display.hardware.pwm_dither_bits or 1 }}"
+                           value="{{ main_config.display.hardware.get('pwm_dither_bits', 1) }}"
                            min="0"
-                           max="4"
+                           max="2"
                            class="form-control">
                 </div>
             </div>
 
             <div class="grid grid-cols-1 md:grid-cols-2 gap-4">
                 <div class="form-group" id="setting-display-pwm_lsb_nanoseconds" data-setting-key="display.hardware.pwm_lsb_nanoseconds">
-                    <label for="pwm_lsb_nanoseconds" class="block text-sm font-medium text-gray-700">PWM LSB Nanoseconds{{ ui.help_tip('Base time for the least-significant color bit (50–500 ns).\nDefault: 130. Raising it can reduce flicker on some panels but lowers the maximum refresh rate.', 'PWM LSB Nanoseconds') }}</label>
+                    <label for="pwm_lsb_nanoseconds" class="block text-sm font-medium text-gray-700">PWM LSB Nanoseconds{{ ui.help_tip('On-time of the least-significant color bit (50–3000 ns); each higher bit doubles it.\nDefault: 130. Lower allows a higher refresh rate but can cost color accuracy or add ghosting; raise it if bright text on black leaves faint trails.', 'PWM LSB Nanoseconds') }}</label>
                     <input type="number"
                            id="pwm_lsb_nanoseconds"
                            name="pwm_lsb_nanoseconds"
                            value="{{ main_config.display.hardware.pwm_lsb_nanoseconds or 130 }}"
                            min="50"
-                           max="500"
+                           max="3000"
                            class="form-control">
                 </div>
 
                 <div class="form-group" id="setting-display-limit_refresh_rate_hz" data-setting-key="display.hardware.limit_refresh_rate_hz">
-                    <label for="limit_refresh_rate_hz" class="block text-sm font-medium text-gray-700">Limit Refresh Rate (Hz){{ ui.help_tip('Caps the panel refresh rate (1–1000 Hz).\nDefault: 120. A steady cap reduces flicker in camera recordings and keeps timing consistent. Set higher or to the max your panel supports for the smoothest motion.', 'Limit Refresh Rate') }}</label>
+                    <label for="limit_refresh_rate_hz" class="block text-sm font-medium text-gray-700">Limit Refresh Rate (Hz){{ ui.help_tip('Caps the panel refresh rate (0–1000 Hz; 0 = no cap).\nDefault: 100. A steady cap reduces flicker from other activity on the Pi and in camera recordings. Scroll speeds are worked out against this value (against 100 Hz when it is 0), so a cap the panel can actually hold keeps scrolling even.', 'Limit Refresh Rate') }}</label>
                     <input type="number"
                            id="limit_refresh_rate_hz"
                            name="limit_refresh_rate_hz"
-                           value="{{ main_config.display.hardware.limit_refresh_rate_hz or 120 }}"
+                           value="{{ main_config.display.hardware.get('limit_refresh_rate_hz', 100) }}"
-                           min="1"
+                           min="0"
                            max="1000"
                            class="form-control">
                 </div>
@@ -304,7 +303,7 @@
                                {% if main_config.display.hardware.disable_hardware_pulsing %}checked{% endif %}
                                class="form-control h-4 w-4 text-blue-600 focus:ring-blue-500 border-gray-300 rounded">
                         <span class="ml-2 text-sm font-medium text-gray-900">Disable Hardware Pulsing</span>
-                        {{ ui.help_tip('Turn off hardware PWM pulsing.\nEnable this if the Pi audio is in use or you hear buzzing / see instability. Slightly increases CPU usage.', 'Disable Hardware Pulsing') }}
+                        {{ ui.help_tip('Time the brightness pulses in software instead of with the Pi hardware PWM.\nLeave unchecked where possible: software timing is less exact, so a row or the whole panel can briefly flash brighter. Hardware pulsing needs the panel OE line on GPIO 18 (Adafruit HAT PWM, Regular, Triple Bonnet) and the Pi onboard sound driver disabled; check this if you need Pi audio. Without GPIO 18 the library uses software timing anyway.', 'Disable Hardware Pulsing') }}
                     </label>
                 </div>
 
@@ -328,7 +327,7 @@
                                {% if main_config.display.hardware.show_refresh_rate %}checked{% endif %}
                                class="form-control h-4 w-4 text-blue-600 focus:ring-blue-500 border-gray-300 rounded">
                         <span class="ml-2 text-sm font-medium text-gray-900">Show Refresh Rate</span>
-                        {{ ui.help_tip('Overlay the live panel refresh rate on the display.\nUseful for tuning GPIO Slowdown and PWM settings; turn off for normal use.', 'Show Refresh Rate') }}
+                        {{ ui.help_tip('Print the live panel refresh rate to the console; nothing is drawn on the panel.\nReadable when you stop the service and run the display in a terminal; under the service the output is buffered. Turn off for normal use.', 'Show Refresh Rate') }}
                     </label>
                 </div>
 

web_interface/templates/v3/partials/plugin_config.html

@@ -6,7 +6,29 @@
 {# ===== MACROS FOR FORM FIELD GENERATION ===== #}
 
 {# Render a single form field based on schema type #}
+{# "x-display": "hidden" keeps a property declared -- so stored configs that
+   still carry it keep validating -- without drawing a control for it
+   (deprecated keys, internal ids). An object whose every child is hidden
+   counts as hidden too, so it doesn't render as an empty section. Outputs
+   "1" when hidden, nothing otherwise; test it with `|trim`.
+   Nothing hidden is posted for a plain or nested field: the save deep-merges
+   the form over the stored section, so the stored value stays. Array rows are
+   the exception (a posted list replaces the stored one), see array-table. #}
+{% macro prop_is_hidden(prop) -%}
+    {%- if prop is mapping -%}
+        {%- if prop.get('x-display') == 'hidden' -%}1
+        {%- elif prop.get('properties') is mapping and prop.get('properties') -%}
+            {%- set _hid = namespace(all=true) -%}
+            {%- for _child in prop.get('properties').values() -%}
+                {%- if not prop_is_hidden(_child)|trim -%}{%- set _hid.all = false -%}{%- endif -%}
+            {%- endfor -%}
+            {%- if _hid.all -%}1{%- endif -%}
+        {%- endif -%}
+    {%- endif -%}
+{%- endmacro %}
+
 {% macro render_field(key, prop, value, prefix='', plugin_id='') %}
+    {% if not prop_is_hidden(prop)|trim %}
     {% set full_key = (prefix ~ '.' ~ key) if prefix else key %}
     {% set field_id = (plugin_id ~ '-' ~ full_key)|replace('.', '-')|replace('_', '-') %}
     {% set label = prop.title if prop.title else key|replace('_', ' ')|title %}
@@ -660,14 +682,20 @@
                     {% set array_value = value if value is not none and value is iterable and value is not string else (prop.default if prop.default is defined and prop.default is iterable and prop.default is not string else []) %}
 
                     {# Use x-columns if specified, otherwise auto-detect first 4 simple properties #}
+                    {# Hidden item properties never become columns (see prop_is_hidden). #}
                     {% set x_columns = prop.get('x-columns') %}
                     {% if x_columns %}
-                        {% set display_columns = x_columns %}
+                        {% set display_columns = [] %}
+                        {% for col_name in x_columns %}
+                            {% if not prop_is_hidden(item_properties.get(col_name))|trim %}
+                                {% set _ = display_columns.append(col_name) %}
+                            {% endif %}
+                        {% endfor %}
                     {% else %}
                         {% set display_columns = [] %}
                         {% for col_name in item_properties.keys() %}
                             {% set col_def = item_properties[col_name] %}
-                            {% if col_def.get('type') not in ['object', 'array'] and display_columns|length < 4 %}
+                            {% if col_def.get('type') not in ['object', 'array'] and display_columns|length < 4 and not prop_is_hidden(col_def)|trim %}
                                 {% set _ = display_columns.append(col_name) %}
                             {% endif %}
                         {% endfor %}
@@ -814,8 +842,16 @@
 
                                     {# Actions cell: delete + optional edit button for advanced props #}
                                     {% set has_advanced = namespace(value=false) %}
-                                    {% for k in item_properties.keys() %}{% if k not in display_columns and k != 'id' %}{% set has_advanced.value = true %}{% endif %}{% endfor %}
+                                    {% for k, v in item_properties.items() %}{% if k not in display_columns and k != 'id' and not prop_is_hidden(v)|trim %}{% set has_advanced.value = true %}{% endif %}{% endfor %}
                                     <td class="px-3 py-3 whitespace-nowrap text-center" style="min-width:90px;vertical-align:middle">
+                                        {# Hidden item properties (e.g. countdown's auto-generated id) get
+                                           no control, but a posted row replaces the stored item wholesale,
+                                           so carry the stored value through. JSON-encoded so the save can
+                                           restore its exact type (an id "1" must stay a string); absent
+                                           values are not invented. #}
+                                        {% for k, v in item_properties.items() %}{% if prop_is_hidden(v)|trim and k in item and item[k] is not none %}
+                                        <input type="hidden" name="{{ full_key }}.{{ item_index }}.{{ k }}" data-hidden-prop="{{ k }}" value='{{ item[k]|tojson }}'>
+                                        {% endif %}{% endfor %}
                                         <button type="button"
                                                 onclick="removeArrayTableRow(this)"
                                                 aria-label="Remove row {{ item_index + 1 }}"
@@ -836,13 +872,23 @@
                                     {# Hidden cell: flat hidden inputs for non-displayed props (layout, style, etc.) #}
                                     {% if has_advanced.value %}
                                     {% set adv_schema = namespace(d={}) %}
-                                    {% for k, v in item_properties.items() %}{% if k not in display_columns and k != 'id' %}{% set _ = adv_schema.d.update({k: v}) %}{% endif %}{% endfor %}
+                                    {% for k, v in item_properties.items() %}{% if k not in display_columns and k != 'id' and not prop_is_hidden(v)|trim %}{% set _ = adv_schema.d.update({k: v}) %}{% endif %}{% endfor %}
                                     <td style="display:none" class="array-table-advanced-data"
                                         data-prop-schema='{{ adv_schema.d|tojson }}'>
                                         {% for prop_name, prop_schema in adv_schema.d.items() %}
                                             {% set prop_type = prop_schema.get('type', 'string') %}
                                             {% if prop_type == 'object' and prop_schema.get('properties') %}
                                                 {% for sub_name, sub_schema in prop_schema.get('properties', {}).items() %}
+                                                    {% set _sub_obj = item.get(prop_name) if item.get(prop_name) is mapping else {} %}
+                                                    {% if prop_is_hidden(sub_schema)|trim %}
+                                                    {# Kept out of the row editor (no data-nested-prop); stored value only. #}
+                                                    {% if sub_name in _sub_obj and _sub_obj[sub_name] is not none %}
+                                                    <input type="hidden"
+                                                           name="{{ full_key }}.{{ item_index }}.{{ prop_name }}.{{ sub_name }}"
+                                                           data-hidden-prop="{{ prop_name }}.{{ sub_name }}"
+                                                           value='{{ _sub_obj[sub_name]|tojson }}'>
+                                                    {% endif %}
+                                                    {% else %}
                                                     {% set sub_val = item.get(prop_name, {}).get(sub_name) %}
                                                     {% set sub_default = sub_schema.get('default') %}
                                                     {% set final_val = sub_val if sub_val is not none else sub_default %}
@@ -852,6 +898,7 @@
                                                            data-prop-type="{{ sub_schema.get('type', 'string') }}"
                                                            data-prop-schema='{{ sub_schema|tojson }}'
                                                            value="{{ final_val if final_val is not none else '' }}">
+                                                    {% endif %}
                                                 {% endfor %}
                                             {% else %}
                                                 {% set prop_val = item.get(prop_name) %}
@@ -1104,6 +1151,7 @@
             {% endif %}
         </div>
     {% endif %}
+    {% endif %}{# not prop_is_hidden #}
 {% endmacro %}
 
 {# Render a nested/collapsible section for object types #}
@@ -1142,7 +1190,7 @@
         <div id="{{ section_id }}" class="nested-content bg-gray-50 px-4 py-4 space-y-3 hidden" style="display: none;">
             {% set property_order = prop['x-propertyOrder'] if 'x-propertyOrder' in prop else prop.properties.keys()|list %}
             {% for nested_key in property_order %}
-                {% if nested_key in prop.properties %}
+                {% if nested_key in prop.properties and not prop_is_hidden(prop.properties[nested_key])|trim %}
                     {% set nested_prop = prop.properties[nested_key] %}
                     {% set nested_val = nested_value[nested_key] if nested_key in nested_value else none %}
                     {# Tagged so a widget that takes over part of a block can
@@ -1295,7 +1343,10 @@
                            them. Schemas without the flag render exactly as before. #}
                         {% set tiers = namespace(basic=[], advanced=[]) %}
                         {% for key in property_order %}
-                            {% if key in schema.properties and key != 'enabled' %}
+                            {# A hidden key is neither drawn nor reported in
+                               __rendered_section, so the save never reads its
+                               absence as an unchecked box. #}
+                            {% if key in schema.properties and key != 'enabled' and not prop_is_hidden(schema.properties[key])|trim %}
                                 {% set prop = schema.properties[key] %}
                                 {% set is_object = prop.type is defined and 'object' in prop.type %}
                                 {% if prop.get('x-advanced') and not is_object %}