Step sensor

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1

Sorry if this question does not belong in this spot/forum, but I figured you guys would know more about sensors than the average group.

I am trying to build a high quality DDR (Dance Dance Revolution) pad. Basically, it detects when a person steps on a given square and sends it to the console/computer.

Most people tend to use a physical switch of some sort; two pieces of metal separated by a springy substance. I am worried about the longevity of such a system.

So, I was thinking about using a strain gauge or a Force Sensitive Resistor for each of the squares, and feeding that into a microcontroller (been playing with AVRs).

Basically, I am looking for advice on a simple sensor that can tell me if someone is standing on it. It needs to be robust (I’m not small… ~250 lbs). And, the fewer the moving parts, the better (Less to break).

I don’t really need anything more than on/off (Step or no step).

Any help on what kind of sensors to try, or even some place to direct me to research more would be great.

2

Force Sensing Resistors (FSRs) would be a great way of detecting steps on a foot pad. Simply use a Voltage Divider to obtain an analog voltage and interface with your AVR’s ADC inputs.

In terms of the mechanical setup, either use multiple FSRs on one pad or a single FSR with a weight distribution strategy to make sure a step along the side of the pad gets recognised. An inverted pyramid type concentrator comes to mind. Perhaps you will opt to use the FSR strips.

They are rated for >10 million actuations and since there are no “moving” parts, they should be robust enough for your project. Although they are not meant to accurately measure weight repeatedly, they will nonetheless also provide an impression of the pressure being exerted. This could perhaps help you to differentiate between a stomp and a tap if you want to be creative.

Feel free to share the progress of your project in the Robot Project Showcase, as this will assuredly interest others.