Calibration Defines Zero; Detection Measures Deviation
The useful baseline is the room's normal operating condition, not an imaginary perfectly quiet environment.
presence
Separate Raw Sensor Data from Interpreted State
Presence, motion and occupancy are conclusions; retain enough underlying evidence to debug those conclusions.
Wi-Fi CSI Presence Detection Fails First at Calibration, Drift, and Synchronization
CSI is extremely sensitive to the radio channel—which is why it can sense motion and why uncontrolled rooms, clocks, channels, furniture, fans, and hardware differences can swamp a naive detector.