Also this is mindblowing, logging keystrokes from a standard keyboard using wifi.
"we show for the first time that WiFi signals can also be exploited to recognize keystrokes. The intuition
is that while typing a certain key, the hands and fingers of a user move in a unique formation and direction and thus generate a unique pattern in the time-series of Channel State Information (CSI) values"
Also this is mindblowing, logging keystrokes from a standard keyboard using wifi.
"we show for the first time that WiFi signals can also be exploited to recognize keystrokes. The intuition is that while typing a certain key, the hands and fingers of a user move in a unique formation and direction and thus generate a unique pattern in the time-series of Channel State Information (CSI) values"
https://www.sigmobile.org/mobicom/2015/papers/p90-aliA.pdf
Edit: I wonder as an aside how precisely you could potentially use the accelerometer etc. for dead-reckoning.