[theprgramerdude]

Do you know why your first derivative potentiometer readings may be unstable? I'd recommend trying to instead take the average derivative over a period instead, so either integrate a few derivative values and divide with respect to time, or just take the readings from the potentiometer at a much slower rate (I'd recommend the first one if your ADC+Pot combo is possibly the issue and you have the compute power, it essentially equates to crude oversampling).