Liquid lens feedback and control

Control systems for liquid lenses can use feedback control using one or more measured parameters indicative of a position of the fluid interface in the liquid lens. Capacitance between a fluid and an electrode in the liquid lens can vary depending on the position of the fluid interface. Current mirrors can be used for making measurements indicative of the capacitance and/or the fluid interface position. The liquid lens can be calibrated using the measurements indicative of capacitance and/or fluid interface position as the voltage is driven across an operational range. A control system can use pulse width modulation (PWM) for driving a liquid lens, and a carrier frequency for the PWM signals can be varied to control power consumption in the liquid lens. The slew rate can be adjustable to control power consumption in the liquid lens.