A device disclosed herein includes a feedback measuring circuit to measure a signal flowing through a movable MEMS mirror. Processing circuitry determines a time at which the signal indicates that a capacitance of the movable MEMS mirror is substantially at a maximum capacitance. The processing circuitry also determines, over a window of time extending from the time at which the signal indicates that the capacitance of the movable MEMS mirror is substantially at the maximum to a given time, a total change in capacitance of the movable MEMS mirror compared to the maximum capacitance. The processor further determines the capacitance at the given time as a function of the total change in capacitance, and determines an opening angle of the movable MEMS mirror as a function of the capacitance at the given time.