This IR compound eye when mounted on a pan/tilt assembly can be used by a robot to track movement within 200mm. 4 pairs of IR photo transistors and 4x IR LEDs allow your robot to measure both ambient and reflected IR. It can also be used as a simple range finder. This sensor does not work in bright daylight as sunlight has a lot of IR and blinds the sensor. The IR LEDs can be controlled by a digital output so that ambient light as well as reflected light can be measured. Your microcontroller needs 4 analog inputs available to use this sensor.