.. highlight:: swift Proximity ========= Proximity sensors detect the presence of objects without physically touching them. They are often used as a touch-less switch, automatically turning on faucets and opening doors to name a few examples. MetaDetector boards are outfitted with the `TSL2671 `_ proximity detector, a photoelectric style detector that refelcts an infrared signal off the target object to measure distance. This sensor is accessed with the `MBLProximityTSL2671 `_ interface. To meet specific needs, different MetaWear models have different magnetometer sensors, so the ``MBLProximity`` class is actually a generic abstraction of all magnetometers. You can up-cast to one of our derived magnetometer objects in order to access advanced features. Cast to Derived Class --------------------- There is currently nothing in the generic ``MBLProximity`` class, so you need to use the `MBLProximityTSL2671 `_ derived class. :: if let proximityTSL2671 = device.proximity as? MBLProximityTSL2671 { }