We present a compact vision sensor comprising a one-dimensional array of adaptive photo-receptors, spatio temporal feature extraction circuits, feature normalization circuits, and an attentional readout circuit that selects the most salient region in the feature map. The sensor comprises also digital input and output circuits for directly interfacing it to digital processing units, making it an ideal device for mobile robotic applications. We describe the sensor architecture and present experimental results measured from the fabricated chip. As we identified unexpected results from one of the computational stages, we compare the measured responses to circuit simulations and propose improvements for new revisions of the chip.