Piezo Transducer for sound effect and acceleration sensing
Recently I have built a remote control tank with sound effect. Since there is not much space in the tank, I decide to use a piezo transducer to do the sound effect. It is a low current device so it can be driven directly by the MCU. However, to make is sound loudly, you have to apply a square wave at its resonant frequency, which is around 3kHz. You have to mount it properly also.
Piezo transducer can be used for acceleration sensing, http://alumni.media.mit.edu/~gan/Gan/Education/MIT/MediaLab/Theses/MS/c5maracas/c5maracas.html#Heading3
I use an op amp and do a simple experiment. It is quite sensitive. I would say it is like a motion/vibration sensor more than acceleration sensor. May be there are some innovative ways to use it.