For my stupid pet trick, I made a stuffed toy fashioned after an LED and placed a homemade fabric pressure sensor inside to create a hug-o-meter of sorts. The fabric sensor was built using two pieces of conductive lamé fabric (tested first with a multimeter at Mood Fabrics) with a piece of Velostat (antistatic material) sandwiched in between. Hugging the LED toy would trigger a series of (real) LEDs to light up in sequence based on the amount of pressure applied by the hug. A velcro opening at the bottom right of the stuffed toy allows the sensor to be easily inserted/removed.
The circular sensor was the second of two attempts. I had originally created a more rectangular sensor to better accomodate the shape of the LED, but found that it was only effective when pressure was applied directly between the two points of wire contact. I had hoped that creating a circular shape for the second sensor would help this problem, but it also seemed only to work when the pressure was placed between the two points.
The code programmed into the Arduino was modified from the analog input lab from Week 2. When placed inside the toy, the fabric sensor generated an output range of approx. 0-500.
And finally, a paper casing for the Arduino to hide the wires.
Good blog post. Nice description with plenty of photo and video documenting how it was done. The videos are succinct and help tell the story when words would be too much.