I have a sensitive micro/nano positioning controller that takes -2V to +12V signals as input. This controller then produces high voltage -20V to +120V as it's own output to actuate a piezo crystal, which contracts and expands microscopically depending on the potential it experiences.
I am aware of how to produce a range of signals from 0-12V DC using a potentiometer and a 12V battery, however, I am not aware of a way to produce -2V to 12V DC signals.
At first I was a bit confused since the potential difference between -2 and 12V is going to be 14V (i.e. "0" to 14V), but then I realized that the controller device itself has it's own "0V" ground, so it's indeed possible to have -2V and +12V relative to that.
I am open to anything since it's critical to get this right, but I don't have too much experience in building electronic circuits using op-amps. Since I am controlling very small movements using this piezo crystal, I would ideally like to produce these -2 to 12V signals with a digital controller - maybe something that goes from 12-bit or 16-bit PWM input to a -2V to 12V output. If there is a way to use a potentiometer I could also use a stepper motor to turn it, but I am still confused as to how to get the -2 to 12V.