strain gauges might work. basically you'd firmly support the corners and or edges of each "pad" of the switch and put a strain gauge right in the middle, using fairly heavy metal (for minimum deflection) or even wood/plastic for the pad you should still be able to detect the resistance change. depending on the application, you could have a stronger support very slightly separated from the sensing surface for safety (i.e. so a truck can drive over it or a very violent strike won't break it). you should have good frequency response and dc sensing is no problem. if you don't know what a strain gauge is just try a google search, they are fairly common and the basis for all electronic scales. you may need to buy them surplus too meet those cost constraints and for a non critical application like this any good epoxy should work rather than the very good epoxy normally recommended. another possibility would be an ultrasonic sensor which could tell if there was something touching the other side of the plate. you'd want to put the transponder right against the metal and would have to ignore the immediate reflections from the surface of the plate, or you could use something like a piezo bonded to the plate in a resonant oscillator circuit and detect the frequency shift/damping/oscillation failure as the plate was loaded and made more stiff. again the pad would be supported around the edges and the sensor would be in the middle. you might have some problem with mechanical noise but it would also be an indicator so might not be a problem. Rick Luddy wrote: > > I'm working on a project to build a dance pad for video games. It needs > four sensors, each one detecting whether or not an 11"x11" panel has > someone standing on it. The end result will look similar to: > http://www.angelfire.com/d20/ddrhomepad/ddrpad1.html > , although I plan to implement it differently. ------- -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.