Infrared Distance Sensor

These sensors work as a pulse of light (wavelength range of 850nm +/-70nm) is emitted and then reflected (or not reflected at all). When the light returns, it comes back at an angle that is dependent on the distance of the reflecting object. By knowing the angle, distance can then be determined. These sensors are commonly used to prevent robots from driving into walls and general object avoidance. Please note that accuracy will usually be reduced when used outdoors due to interactions with sunlight.