Every Wi-Fi packet carries unencrypted physical-layer information — Channel State
Information — that reflects off human bodies. WISPR listens to those reflections
with two commodity ESP32 nodes costing under $40 total, and detects presence,
motion state, and walking direction through walls, with no
cameras and no network credentials.
A multi-stage pipeline — EMA smoothing, rolling percentile normalisation,
dual-threshold hysteresis, and a four-strategy direction inference algorithm —
turns raw subcarrier amplitudes into spatial tracking, entirely passively.
ESP32 / ESP-IDF · CSI sensing · Python · NumPy · Matplotlib · UDP · signal processing · privacy research