Audience Display

Custom FRC audience display used for offseason events (built for Rainbow Rumble, themeable for others). A Bun server connects to FMS over SignalR + REST and drives a Svelte UI that renders every audience screen: match preview, live score bar, score reveal, alliance selection, selection break timer, rankings, playoff bracket, and field timeout.

Screens follow the FMS video switch directly, so the display is operated entirely from the normal FMS match control page (including the alliance-selection wizard's Break Timer button).

Profiles

The look is defined by a profile; screens a profile doesn't override fall back to default.

Profile	Notes
default	Red/blue theme, all screens
wrc	Re-theme of default (colors/assets only)
rainbow-rumble	Full restyle of every screen

Pick the profile from the gear menu on the display page (bottom-right hover); the choice is stored server-side, so every connected display switches together.

Running an event (Windows exe)

Grab audience-display-<version>.exe from the latest release and run it on a machine that can reach FMS. Open http://localhost:3001/display in a fullscreen browser (OBS browser source works too).

• FMS is expected at 10.0.100.5. For a local FMS install: $env:FMS_URL = "127.0.0.1" (PowerShell) before launching the exe.
• Auto-update: on startup the exe checks the latest GitHub release, downloads the new versioned exe next to itself, relaunches, and cleans up old versions on the following boot. Set AUTO_UPDATE=0 to disable.
• Display URL parameters: ?inverted=true (swap red/blue sides), ?top=true (score bar at the top), ?transitionAfterMatchEnd=<seconds> (auto-switch to the waiting screen after the match ends; default -1 keeps the score bar up until scores are committed).

FMS traffic logging

The server records every SignalR frame and REST response to a SQLite database (%APPDATA%\audience-display\fms-log.sqlite) for protocol reverse-engineering. If sync credentials are configured (baked into release exes via CI secrets, or a log-sync.json / LOG_SYNC_USER/LOG_SYNC_PASS/LOG_SYNC_URL env vars), new rows are uploaded as gzipped NDJSON chunks every 10 minutes and after every finals match. Merge chunks back into one database with bun tools/import-fms-log-chunks.ts.

Development

Requires bun. Install once with bun install, then run the server and UI in separate terminals:

bun run server:dev   # display server on :3001
bun run ui:dev       # vite dev server on :5173, proxies the websocket to :3001

The server targets FMS_URL (default 10.0.100.5). For development without a real field, run fake-fms - a Bun/TypeScript FMS emulator with a control panel, scripted test scenarios, and wire-faithful SignalR/REST behavior - and point the server at it with FAKE_FMS=1.

Building the exe

bun run exe:build   # bundles the UI, embeds it, cross-compiles to audience-display.exe

Releases are automated: pushing a v* tag builds the exe (with log-sync credentials baked from repo secrets) and publishes it as a versioned GitHub release asset, which running installs then pick up via auto-update.

Repo layout

packages/lib      shared types (FMS wire DTOs, display state)
packages/server   Bun server: FMS SignalR/REST client, state, logging, auto-update
packages/ui       Svelte UI: profiles, screens, sounds
tools/            log-chunk import utility