Hi there!
I’m looking for an easy way to wirelessly detect vibrations and have it available in realtime to a server or any source! The cheapest way I know how (which isn’t that cheap) would be using a WiFi shield with an Arduino and a Piezo Sensor (https://www.sparkfun.com/products/9197)
Is there anything anyone else can recommend? I don’t care about the size of the device, but I’d like the cheapest possible way.
Thanks! 
What type of vibrations? Angular, linear, tiny in amplitude, or large? How big can the device be? How is it to be powered and for how long? How cheap is cheap? How far a transmission range do you need?
It is often best to state the problem (I need to sense a mole tunneling underground from 50 feet away without running lots of wires) rather than a solution (cheapest wireless vibration sensor). You may be missing clever ideas to solve your problem.
Hi Skye!
Thanks for the response. I’m looking to grab vibrations from a motor - like having this device on the top of a car hood and sensing any sort of vibration (binary though, so I don’t care how strong the vibration is, just that it’s present).
The device should be no bigger than 8-12 inches, but I’d prefer a smaller detection device if possible. The transmission range would only be through a floor- like this sitting in a garage and connecting to the wifi network upstairs.
I essentially want to detect when a motor is vibrating and communicate that wirelessly in as cheap of a method as possible. My current idea is to use an arduino with a wifi shield and a sensor - so the amount of wires isn’t the issue, packaging doesn’t have to be sexy!
Couldn’t get any easier than this: http://www.mytaglist.com
You could also look at the Parallax sensor (not much different than the SFE one though).
http://www.parallax.com/Store/Sensors/P … fault.aspx
You could combine that with a zigbee or bluetooth module and a micro. At the other end you could have your wifi shield or ethernet shield. This is a bit more expensive than having the wifi on the sensor side, but allows multiple sensors.
Instead of a vibration sensor, could I use a coil around the wire to detect current flow since all I care about is binary detection?
What, exactly, are you trying to detect? Is your goal to determine whether an electric motor or a gasoline engine is running? If so, what type and size of motor?
Quite possibly yes ... but you need to elaborate on your system and intended usage some more.hellooperator:
Instead of a vibration sensor, could I use a coil around the wire to detect current flow since all I care about is binary detection?