Disclosed herein is a mirror controller for an oscillating mirror. The mirror controller includes a processor configured to receive a mirror sense signal from the oscillating mirror and to determine a phase error between the mirror sense signal and a mirror drive signal. The processor determines the phase error by sampling the mirror sense signal at a first time, sampling the mirror sense signal at a second time at which the mirror sense signal is expected to be equal to the mirror sense signal as sampled at the first time, and generating the phase error as a function of a difference between the sample of the mirror sense signal at the second time and the sample of the mirror sense signal at the first time.