ACTIVE SONAR / BROWSER EXPERIMENT
Follow the echo.
Short bursts of sound. Tiny changes in their return.
A FingerIO-inspired experiment in tracking movement.
Echo-path change
MIC OFFA space for small movements.
Start the mic to measure a returning echo,
or try the clearly labelled simulation.
Echo profile
AFTER ROOM SUBTRACTIONPeaks show candidate reflections. A peak alone does not identify a finger.
Echo history
MOST RECENT AT RIGHTThis is an echo-delay map: it follows returning bursts over time.
Two-microphone positioning +
For live 2D, use two independent, synchronized microphone channels and enter the measured hardware layout. Mic 1 is left, mic 2 is right, both on the X axis. Coordinates describe the selected speaker and the same drawing plane. Position is solved on the positive-Y side of the mic line.
Live 2D is unavailable until distinct channels and hardware geometry are confirmed. Simulation uses a known 13.5 cm mic spacing.
Verification & research notes +
This adaptation transmits real OFDM bursts with a cyclic suffix, correlates echoes, subtracts the room, and refines delays using phase across subcarriers. Browser timing and hardware differ from FingerIO’s native prototype.
Neither the simulation nor the checks establish real-world finger accuracy. One input gives an echo-path measurement. 2D requires the additional hardware conditions above. The original paper’s 8 mm result is not a claim about this site.