Hi, totally new to this. I am thinking of using piezoelectric microphones to create a voltage from vibration and wirelessy transfer those signals (4 discrete units) to a handheld device which will collate that information, displaying relative vibration strength and would be lovely to also have an audio signal output to hear each individual sensor..... asking too much????
it might work, but without a better explanation of what you are trying to do we can't help much. "create a voltage from vibration and wirelessy transfer those signals" is quite vague. You could be describing anything from a sound locator to a seismograph. What signals? Analog or digital? How far?
Im trying to attach sensors to the chassis of a car and see where vibrations from bad wheel bearings or tires are coming from. It needs to be an analog signal, hopefully at both ends, assigning a value scale before transmission of signal and converting that to a graph at the other end would be acceptable as im thinking transmitting an analog signal is probably more power intensive and difficult than simple numerical values encoded digitally.
In general it's easier to reliably and noise free transmit a digital signal than an analog signal.
I'd want to convert the readings of the vibration sensors into some kind of digital signal as close to the source as possible, and then transmit that signal over some digital channel, preferably wired (all the metal and electric noise in a car are not good for wireless transmissions, and you have to bring power to the sensors anyway).
As it's a car, CANBUS comes to mind.
wvmarle thanks for your input on this. I work in an automotive shop so im sure you can understand why i want to build this, in response i must say using the CAN bus is probably out of the questions. I have enough microcontrollers, batteries and sensors to build 4 sensing units and a reciever. But what you said did strike a cord, I could use the vehicle power and ground to power a single controller that is attatched to all four sensors and mounts underneath the car and is wired togethher instead of using a controller for each sensor.... So 4 sensors connected to on arduino under the car, sensor information encoded into a digital signal for wireless transmission to Arduino inside of vehicle (arduino running serial display to laptop) and just view the information I need there!! man u helped my thinking alot here 
in fact there are enough pins on my board i could attatch both vibration and microphone sensors, so i could not only visualize but also LSITEN to each individual wheel!! BTW any idea why this is happening (see picture), can i not use two seperate timed events? and the wavefuncdtion at the bottom inverts past neutral@////. why???
Hi,
OPs pic.
Please read the first post in any forum entitled how to use this forum.
http://forum.arduino.cc/index.php/topic,148850.0.html .
Then look down to item #7 about how to post your code.
It will be formatted in a scrolling window that makes it easier to read.
From what I can see the you have the top channel set to DC input , which is what you need.
The lower channel is in AC input mode, check your scope settings.
If you swap channel connections on your project you will find the lower trace will still look spikey.
Tom....