Skylight

Project the aircraft passing overhead onto your ceiling, in real time — an X-ray through the roof.

🛰️ Get notified when I launch on a crowdfunding platform → skylightceiling.com
_{A ready-made kit is coming. Join the waitlist for early access & launch pricing.}

https://github.com/user-attachments/assets/9256b0eb-cc27-4388-9a4f-0a6c05468304

Skylight decodes ADS-B from a cheap RTL-SDR radio and renders the planes physically flying over you onto a ceiling-pointed projector. A jet you'd hear overhead glides across your ceiling at the same moment — labeled with its airline, type, and where it's headed. Pure-black background so the projector's rectangle disappears and only the aircraft (and stars) are lit.

It also draws the real sky behind the planes — sun, moon, bright stars and constellations, and live satellites including the ISS — all at their true positions for your location and time. Tune everything from your phone.

Reference build is centered on San Francisco International (SFO), but it works anywhere — set your coordinates (and swap the runway data) and you're flying.

• Real-time overhead aircraft from a local RTL-SDR (sub-second), or from a free web API with zero code changes — handy for trying it with no radio.
• Type-aware glyphs in a luminous, swept-wing style: widebodies tower over regional jets, helicopters spin their rotors, turboprops and GA aircraft spin their props.
• Smooth motion — interpolates the ~1 Hz fixes to 60 fps by rendering slightly in the past and tweening between real positions (no teleporting).
• Comet trails, altitude-graded color, and range rings + compass for orientation.
• The airport (runways) drawn at its true position, so you watch departures and arrivals line up with the runway.
• Window to elsewhere — each routed flight shows its destination city, local time there, and miles-to-go, plus a faint great-circle arc toward where it's headed.
• Live sky layer — sun, moon (with phase), bright stars + constellation lines, and satellites / ISS computed from TLEs. Scrub time forward/back from your phone, or jump straight to the next ISS pass.
• Phone control panel — every setting (rotation, theme, palette, filters, sky toggles, …) is live-tunable over your LAN and persists across reboots.
• Appliance-ready — boots straight to a full-screen kiosk on a Raspberry Pi 5.

Hardware

Part	Suggested	Notes
Receiver	RTL-SDR Blog V4 + dipole	The included dipole is plenty — planes are nearly overhead.
Compute	Raspberry Pi 5 (8 GB)	Decode + render. Active cooling for 24/7.
Projector	A 1080p projector pointed up	Laser (e.g. Optoma GT2100HDR) gives the deepest blacks, but it's overkill — see the budget tip below.
Display link	micro-HDMI → HDMI	The Pi 5 uses micro-HDMI (not mini).
Mount	Rotating 1/4-20 stand, pointed up	Lower the stand for a bigger image; tape + a safety tether.

💡 Budget tip — you don't need an expensive projector. The pricey laser short-throw is only worth it if you want the image visible in a lit room. If you're happy viewing it in a dim/dark room (the intended vibe), a cheap native-1080p LED projector like the Yaber Buffalo Pro U9 (~$150) works great:

• No short-throw needed — from the floor under an ~8 ft ceiling, even a 1.35:1 throw gives a ~5.5 ft image.
• Low brightness is fine (even better) — the content is sparse-on-black, so 200–400 lumens in a dark room actually looks deeper.
• Just verify it's native 1920×1080 (not "1080p supported"), has a quiet fan, and an HDMI input that shows on power-on.

The build — short-throw projector pointing up, RTL-SDR dipole on the cabinet.

You don't need any of this to try it — see Quick start.

Quick start (local, no radio)

Runs entirely on your computer against a free public ADS-B API.

pnpm install
DATA_SOURCE=api pnpm dev

• Display: http://localhost:5173/
• Control panel: http://localhost:5173/control.html (or from your phone: http://<your-ip>:5173/control.html)

Set your location in the control panel area is coming; for now set centerLat / centerLon in shared/src/config.ts (defaults to SFO).

With a radio (locally)

scripts/install-rtlsdr-fedora.sh    # rtl-sdr-blog driver + blacklist DVB-T (Fedora; see script for Debian)
scripts/run-dump1090-local.sh       # decode + serve aircraft.json on :8080
DATA_SOURCE=radio pnpm dev

Raspberry Pi appliance

Full walkthrough in pi-setup/README.md: flash + headless provision the SD card, install the driver + decoder + app, and set up the boot-to-kiosk display. Once it's running, push updates from your dev machine with:

PI_HOST=skylight.local ./scripts/deploy-to-pi.sh

Configuration

Config (shared/src/config.ts) is the single source of truth, persisted to server/data/config.json and live-editable from the control panel. Key fields:

centerLat / centerLon	Your location — where you're looking up.
radiusMiles	How far out to show (default 3 — "what you could realistically see").
rotationDeg / mirrorX	Calibration for the looking-up flip (tune against a real pass).
theme	ambient · telemetry · focus.
showStars / showSun / showMoon / showSatellites	Sky layer toggles.
skyTimeOffsetMin	Scrub the sky clock for testing (0 = live).
showDestArc / showRouteDetail	"Window to elsewhere".

Using it somewhere other than SFO: set centerLat/centerLon, and replace the runway geometry in web/src/display/airports.ts with your local airport (coordinates from OurAirports). Stars, sun, moon, and satellites are computed for your coordinates automatically.

Server environment

Env	Default	Meaning
DATA_SOURCE	radio	radio (dump1090) or api (airplanes.live)
AIRCRAFT_JSON_URL	http://localhost:8080/aircraft.json	dump1090 feed
SUPPLEMENT_API	1	When on radio, merge the API too (keeps landing aircraft alive)
PORT / HOST	3000 / 0.0.0.0	HTTP + WebSocket

Architecture

RTL-SDR ──USB──> dump1090-fa ──> aircraft.json (:8080)
                                      │ poll ~1 Hz  (+ API supplement)
                                      ▼
                         server/  (Node · Express · ws)
                         • normalize + enrich (airline/type tables + adsbdb routes)
                         • proxy satellite TLEs (Celestrak)
                         • persist config, broadcast over WebSocket
                         ├──────────────────────┬───────────────────────┐
                         ▼                      ▼                       ▼
                   Display (/)            Control (/control)        REST /api/*
                   canvas renderer +      phone settings UI
                   sky engine → projector (live, two-way)

• shared/ — TypeScript types, config schema, and pure geo/projection math.
• server/ — polls the radio (primary) and API (supplement), enriches aircraft, proxies TLEs, persists config, and pushes everything over a WebSocket.
• web/ — Vite + React, two pages: the display (<canvas> renderer + celestial engine) and the mobile control panel.

Stack: TypeScript · React · Vite · Express · ws · pnpm workspaces · astronomy-engine · satellite.js.

Credits & data

• ADS-B decode: dump1090-fa · RTL-SDR Blog drivers
• Routes / aircraft enrichment: adsbdb · fallback feed: airplanes.live
• Satellite elements: Celestrak · airport data: OurAirports

License

MIT — be excellent, point it at the sky.