I'm planning to build a project similar to the one in the video. However, I'm undecided about whether I should use a vibration sensor or a pressure-detecting sensor. Alternatively, is there an off-the-shelf product available that can detect footsteps?
IIRC, most of them work off a pendulum of some kind. You enter your avg stride length and it then does the simple math.
I wonder if any of them use GPS?