Input devices

Input devices

Keyboards, mice, touch screens, microphones, cameras, scanners and barcode / QR readers.

Transcript

A keyboard sends a code for every key you press. An optical mouse shines a light on the surface, and a sensor tracks how it moves.

A touch screen detects where a finger lands. Resistive screens sense pressure, capacitive ones sense the electricity in your finger, and infrared ones sense a broken beam of light.

A microphone turns sound waves into an electrical signal. A digital camera uses a sensor made of millions of tiny light detectors, one for each pixel.

A scanner lights up a page and records the reflection. A two D scanner makes a flat image, and a three D scanner measures an object's shape to build a model.

A barcode scanner shines a laser across the black and white lines. The reflected light is read as a number, then looked up in a database.

A Q R code stores much more, in a square of dots, in two directions. A phone camera reads it and finds a web address, for example.

Keyboards, mice, touch screens, microphones, cameras, scanners, and barcode readers. They turn the real world into data.

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