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xyu
02-27-2007, 01:01 PM
My name is Xiao Yu and I'm an electrical engineering student at UT Austin.
I recently purchased a FSR strip from Trossen Robotics to use for my
senior design project.

I have a question in its application however.

So what we are trying to do is to make a touch sensing guitar. We have cut
the FSR strips into 2cm by 2cm squares and will use one square for one
note. Because of the nature of the squares, we cannot use the pre-soldered
connection. I now have to find a way to solder two wires into the square
so that I would get an extremely reliable connection each time and that
the wires touching the sensor would not set off a huge drop in resistance.
I'm still not quite sure how I can mount or solder a resistor to the strip in
order to change its sensitivity. I have the analog cable, so do I solder the resistor
behind the pin connection where there is a metallic bar?

I have done some experiments by mounting the square onto a cardboard box.
I've punctured holes on the solid stripped part of the strip and put wires
through there. However, the connection was not very reliable and my data
was largely arbitrary. I then preceeded to remove the top layer of the
square, thereby exposing a solid black square. I noticed that doing this
completely ruined the FSR square. I wanted to ask for expertise on
how I can solder two wires into each square for a connection onto a
breadboard.

Also, I need for a microcontroller (68HC12) to be able to pick up when the
FSR strip has been pressed. I'm assuming I would be using the
microcontroller to read a change in voltage since pressing the FSR
material will decrease the resistance of the strip. Could you give me a
suggestion on what type of simple circuit I can use to pick up on this
difference? I'm currently experimenting with low voltages (0-5V) since my
microcontroller will be fried if I have a high voltage. Let me know if
there is anything I can be more clear about, thanks!

Xiao Yu