Split-flap displays fail mechanically, and the API can't see a stuck flap. This cycles all 132 bits through every character while a camera watches, so the log and the video disagree exactly where the hardware is broken.
A diagnostic tool for a Vestaboard split-flap display. It steps every one of the board's 132 flap units through all 64 physical character states, one frame at a time, so you can record the board on camera and check that each flap actually turns to the character it was told to show. This catches mechanically stuck or misaligned flaps that the board's own status readout cannot detect.
Before advancing to the next frame, the tool confirms the board reported the full grid it was sent. The flaps take longer to physically settle than the board takes to acknowledge a write, so manual Previous, Next, and Replay controls are the primary way to work through a test pass.
The interface runs in a browser and is reachable from any device on the same local network, and each write is logged so the results can be lined up against the recorded video afterward.
Features
- Steps every one of the board's 132 flap units through its full character set, one frame at a time
- Covers every letter, number, symbol, the degree sign, and all seven color tiles
- Keyboard shortcuts for hands-on testing: start, pause, step forward or back, replay a frame
- Waits for the board to confirm each frame before moving on
- Downloadable timestamped log lines up your camera footage with what the board was told to show
- Runs in a browser, so any phone or laptop on your home network can drive the test
- Automatic run-through mode for hands-off experimentation
Under the hood
- —Local API readback confirms the full 6×22 matrix before each frame advances; it verifies the controller's intended matrix, not physical flap completion, and that gap between electrical and mechanical confirmation is the core engineering constraint the tool documents
- —Manual stepping is the primary mode because flap settle time exceeds write acknowledgment time; automatic mode ships with its timing caveats documented
- —Character set derived from 64 physical wheel positions (codes 0–69 minus six unsupported gaps); semantic codes 70/71 excluded as non-addressable physical positions
- —Exportable timestamped JSON log correlates video timestamps with expected states and any failed writes
- —API key stays server-side and is never sent to the browser; the UI is a thin client
- —LAN binding with zero auth by design; threat model explicitly scoped to trusted local network
