Ask HN: Is it really possible to use a WiFi signal as a motion sensor?
"Guardingo transforms the WiFi that you already have at home in a security system by analysing the radio waves. Radio waves are like waves in water, but they are invisible instead. Imagine a pond. The water in a pond is usually still. When you drop a stone in a pond, you can see ripples all around. If you can see the ripples, you can also prove that something happened to the pond. When a person/stone enters in the house/pond, there are ripples in the radio/water waves. Guardingo can see these ripples."
Source: http://guardingo.net/about.html It's been done at least a couple of times at MIT: http://people.csail.mit.edu/fadel/wivi/ And at University of Washington: http://wisee.cs.washington.edu/ And you can check the references of those papers for other sources. Now, whether an app on a smartphone can get enough RF data to do it, is probably an open question, as all of those projects used something custom or other. Hi, some people at first think that this has been done before, but after going in depth in the guardingo paradigm it is clear that we are the first to detect intrusions with WiFi by using only off-the-shelf devices without any custom hardware modifications, as our method is inherently software. Mauro Pelosi, Ph.D.
co-founder & COO
Ekin Labs Oy
Website: www.guardingo.net
Blog: http://guardingo.tumblr.com/ Some more info about Guardingo:
https://angel.co/guardingo and an interview with the Team: http://superbcrew.com/guardingo-the-first-security-system-us...