Hi Guy,

I would add two comments to the rest of the responses you've garnered. One, You mentioned a "sensitivity" of eight levels, but the context sounded like you were talking about resolution. Sensitivity is a measure of the weakest signal your ADC will detect, whereas resolution is a measure of the smallest increment of signal you can detect (the number of discrete steps, or counts, in the maximum signal you can measure).

Second, you may want to have a backup plan to using a piezo as your primary transducer. As someone already pointed out, they can put out quite large signals. If you find the piezo is too problematic, research strain gauges and wheatstone bridge circuits.

Good luck,

Joe