Connect a piezo sensor board to audio-jack

Hi,

I’ll like to connect the “Grove - Piezo Vibration Sensor” to an audio-jack, but I have some doubts about the connections.

"Grove - Piezo Vibration Sensor" connections : OUT; VCC; GND

OUT -> audio-jack (+)
? -> audio-jack (-)

VCC -> arduino (5V)
GND -> arduino (gnd)

How I make the ? (gnd) connection to the audio-jack (-) ?
(from a gnd of the arduino?)

http://www.seeedstudio.com/depot/grove-piezo-vibration-sensor-p-1411.html?cPath=25_26
http://www.seeedstudio.com/wiki/Grove-_Piezo_Vibration_Sensor

thanks,
Carlos Esteves

You are going to have to give us more clues as to the application you are trying to do.

Generally all the grounds in a circuit need to be connected together or the 'ground' will be different in the different part of the system.

Hi,

I simply want to connect this piezo board to a 1/4 audio jack to connect an audio-interface.
It will not be possible?
Or should I connect the GND to the audio jack instead of connecting to the arduino?

thanks

All the GND should be connected together (Arduino, Piezo, jack).