How do you shift a signal to reference a virtual ground in an instrumentation amplifier? : <p>I'm working on a circuit that needs to amplify a signal based on a changing resistance. The hardware that I have to work with can only make an offset square wave, but I need an input that is centered around 0V. I have tried using an instrumentation amplifier with one voltage set as the excitation signal and the other is the virtual ground, but it still fails to center the signal.</p>

<p>Any ideas of what to do to shift the signal?<a href="https://i.stack.imgur.com/1XhlI.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/1XhlI.png" alt="circuit"></a></p>
