In the form of the GP2D02, Sharp have produced a sensor which, with the aid of a microcontroller, can provide reasonably accurate measurements of distances in the range 10 to 80 cm.Originally developed for use as a proximity switch in sanitary ware, this sensor is also ideal for detecting objects in robotics applications or as a parking aid. The distance is reported as an 8 bit value output serially on a single pin, which can be subsequently processed in software. The sensor includes an infrared transmitter diode along with a suitable receiver and processing electronics. The component is so designed that ambient light and the colour and reflective properties of the object being detected have practically no effect on the measurement results.