Holybro PMW3901 Optical Flow Sensor

The PMW3901 Optical Flow Sensor is a compact motion-tracking sensor that detects movement across a surface by analyzing changes between consecutive image frames. It calculates relative motion in X and Y directions internally and outputs precise displacement data rather than full images. Commonly used in drones and robotics, the PMW3901 helps estimate horizontal movement and improve stability, especially in GPS-denied environments.