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A modern smartphone carries a set of tiny sensors: an accelerometer and a gyroscope that track movement and rotation, a magnetometer that works as a compass, light and proximity sensors, often a barometer, and a satellite receiver that works out where you are.

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Most of these sensors are MEMS, micro-electro-mechanical systems: tiny machines etched into silicon chips, with moving parts measured in thousandths of a millimetre. The accelerometer senses how a minute weight on springs shifts as the phone moves, which is how the screen knows when to rotate and how steps are counted. The gyroscope measures turning and helps steady photos and video. The magnetometer detects the Earth's magnetic field so maps can point north. The light sensor adjusts screen brightness, and the proximity sensor turns the screen off when you hold the phone to your ear. A barometer measures air pressure, which reveals how many floors you have climbed. For location, the phone times signals from several satellites and checks them against nearby Wi-Fi networks and phone masts. The first iPhone, in 2007, already had accelerometer, light and proximity sensors; a gyroscope followed in 2010.

Türkçe oku
Günümüzün akıllı telefonlarında bir dizi minik sensör bulunur: Hareketi ve dönüşü izleyen ivmeölçer ile jiroskop, pusula işi gören manyetometre, ışık ve yakınlık sensörleri, çoğu modelde bir barometre ve nerede olduğunuzu bulan bir uydu alıcısı.

Bu sensörlerin çoğu MEMS, yani mikro elektromekanik sistemlerdir: Silikon yongaların üzerine oyulmuş, hareketli parçaları milimetrenin binde biriyle ölçülen minik makineler. İvmeölçer, telefon hareket ettikçe yaylara bağlı minicik bir kütlenin nasıl kaydığını algılar; telefon ekranı ne zaman yan çevireceğini bu sayede bilir, adımlarınızı da böyle sayar. Jiroskop dönmeyi ölçer ve fotoğraflarla videoların titrememesine yardım eder. Manyetometre Dünya'nın manyetik alanını algılar, böylece harita kuzeyi gösterebilir. Işık sensörü ekran parlaklığını ayarlar; yakınlık sensörü ise telefonu kulağınıza götürdüğünüzde ekranı kapatır. Barometre hava basıncını ölçer; telefon kaç kat çıktığınızı buradan anlar. Konum için telefon birkaç uydudan gelen sinyallerin süresini ölçer ve bunu yakındaki Wi-Fi ağları ve baz istasyonlarıyla karşılaştırır. 2007'deki ilk iPhone'da ivmeölçer, ışık ve yakınlık sensörleri zaten vardı; jiroskop 2010'da eklendi.

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