An optoelectronics apparatus selectively drives a light source, and includes four electrically isolated photodetector (PD) segments that detect light that has reflected off an object. Each of the four PD segments produces a corresponding signal, referred to as signals A, B, C and D, indicative of the light detected by the respective PD segment. Circuitry is used to produce a first motion signal indicative of a sum of the signals A plus B minus a sum of the signals C plus D, i.e., the first motion signal is indicative of (A+B)−(C+D). Further circuitry produces a second motion signal indicative of (B+C)−(A+D). Additional circuitry produces a signal and/or data that is indicative of a direction and/or rate of motion of an object, in dependence on the first and second motion signals.