I've been going over and over what's the best way to do the current output. I'd like to be able to display this on my oscilloscope in XY mode. And for that matter, I'd like to have the differential voltage across the memristor displayed as well. I think the best way to get this done is to use the DAC0 and DAC1 outputs on the Due. That alone wouldn't be too tough; however, I want to have a true negative voltage (and current). I think the best way to get this done is to create a negative voltage supply, and use an op-amp to level shift the DAC output.

I may need to do some calibration of this to set my zero. I'll think about it some more, but I'm not sure if I'll come up with a better solution. But first, I can output the current and differential voltage and see how that looks on the XY display.