This paper proposes an optical motion sensor aimed towards small robotic platforms. It incorporates a 20×20 pixel continuous-time CMOS silicon retina vision sensor with pixels that have local gain control and adapt to background lighting and a DSP microcontroller which computes the global optical flow from the sampled sensor output. The system allows the user to validate various motion algorithms suitable for the platform. Measurements are presented that show that the system can compute global 2D translational motion from complex natural scenes using the image interpolation algorithm at a sample rate of 1 kHz and for speeds up to ±1000 pixels/s using <5k instruction cycles per frame.