MemKey and Touch Sensors

John Burrow

All,

I am working to update a control panel that I made. The control panel is made from Lucite (a clear plastic sheet that looks like glass),·with a pattern on the underside, to give a clean, flat surface. Currently, the control panel is connected to a custom·device I purchased seperately a few years ago. The panel·is·operated by holding a small magnet near the surface, and this activates one of 15 reeds switches·on the underside.

I would like to replace the custom device with a BS2P, and for this I have purchased a MemKey for the interface. I am sure that the current system of reed switches would work with the MemKey, but I would like to go to a 'touch' solution so I do not need the magnet.

I have been looking at the "Piezo Film Vibra Tab Mass" (what a name...).

Here's the question....
- Can anyone tell me if the "Piezo Film Vibra Tab Mass" will work as an input to the MemKey?

Thanks, John Burrow

Paul Baker

I would say that the piezo film vibra tab mass would not be a good fit for the memkey. The tab produces a high voltage/low current brief pulse which may not register as a signal to the memkey.··One possible way of achieving a touch solution is to use the QT113-D Touch Sensor. This is a little more complicated to work with but all of the complex analog front end is taken care of in the chip.

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Paul Baker
Propeller Applications Engineer

Parallax, Inc.