Map every LED in an addressable-LED installation in 3D — with just a phone — then design light effects that flow across the real geometry and play them live on the controller.
Mount your LEDs however you like (a sculpture, a ceiling, a sign, a tree), walk
around the lit fixture with your phone, and splanc recovers the (x, y, z)
position of every LED. Then you author effects in a browser editor and stream
them to the device, where they run across the fixture's true 3D shape instead of
a guessed layout.
No ARCore, no LiDAR, no depth sensor — capture runs in any modern phone browser (rear camera + motion sensors), and a visual-inertial solver estimates the camera path and the LED positions together.
▶ Watch the intro video
The app is a PWA — nothing to install:
- Onboard your controller. Starting from a brand-new ESP32-C6 dev board? Flash the firmware onto it straight from the PWA over USB (desktop Chrome/Edge via Web Serial, or Android Chrome via WebUSB) — no toolchain needed. Then put it on your WiFi over Bluetooth and connect to it on your LAN (you accept its self-signed certificate once).
- Capture a map. Start a mapping session and walk a slow arc around the lit fixture until the live preview converges, then save the map.
- Clean it up. In the mapping workspace, tidy the recovered topology (skeleton extraction, junction cleanup) and send the map to the device.
- Design effects. Open the effects editor, pick or write an effect, preview it against your map, and send it to the controller to play for real.
- Controller: an ESP32-C6 running the firmware in
firmware/, or a Raspberry Pi (seepi/). The controller drives the LEDs, runs the effects VM, and serves the secure control channel. - LEDs: addressable strips or pixels (SK9822 / APA102 / WS2812-family).
- Capture device: any phone with a rear camera and motion sensors (Android / Chrome is the primary target).
- Blink code. The controller drives the LEDs through a short, self-clocking color code that gives every LED a unique temporal signature.
- Capture. You walk around the fixture with the phone. The camera decodes each LED's code frame-by-frame while the phone's motion sensors track its pose.
- Solve. A visual-inertial bundle adjustment recovers each LED's 3D position (and the camera trajectory), metric-scaled and gravity-aligned.
- Topology. The point cloud is turned into a skeleton — strands, segments, junctions and loops — so effects can address the fixture by its shape, not just its coordinates.
- Effects. You write GLSL-ish shaders in the browser editor (per-LED position, segment, distance fields, textures), preview them live, and the compiler emits compact bytecode.
- Play. The bytecode runs on the controller's effects VM, streamed over a secure WebSocket — so what you see in the editor is what lights up.
- Contributing & building from source:
DEVELOPERS.md - Design & architecture:
led-mapper-design.md— the durable spec — plusdocs/ - Project history / build log:
WORKLOG.md