Often, for reasons of weather or otherwise, I will exercise on a step platform. I count the steps mentally, but I want to wire up an AVR to do it for me so I can just zone out on music or the TV. So what I'd like to find is some way to detect each time I step on the platform. I was thinking of some kind of impact sensor, but I'm not wedded to that. What's important is that it is easy to interface to an AVR, perhaps via comparator or ADC. Each impact is in the form BUMP-bump (leading foot - trailing foot). Any ideas?