I'm looking for some advice with trying to interface a vibrating wire sensor to the Arduino.
The sensor is used to measure strain, it is mounted to a surface and then a electromagnet inside the sensor is excited. This causes an attraction to a thin wire within the unit. When the excitation is released the wire is supposed to vibrate at its resonant frequency (which changes with strain).
The returned wave comes down the same set of wires which are used to excite the sensor and I am having trouble trying to measure the frequency! I have tried to use a H bridge type arrangement so that I can disconnect the sensor from the Arduino outputs but I still don't see any values returned. I have the sensor connected to a op amp configured with a 2.5v ref to allow for positive and negative swings.
I can hear the sensor activating, and can produce a tone with it if supplied with a sweep of frequencies.
Any help would be greatly received.