*4.3. Light Sensor*

In recent years, smartphones have prevailed as sophisticated, multifunction mobile phones. One of their main advantages is the incorporation of sensors that lets us monitor environmental properties as illuminance or ambient temperature, among others. These sensors are hardware-based and are not available in all of the products; its presence depends on the manufacturer's decision.

An ambient light sensor is a simple sensor included in most of the recent smartphones and is used commonly to control the screen brightness based on the surroundings, therefore saving battery from energy consumption from the screen and at the same time optimizing the visibility [24]. This sensor has been used in different research in different ways to study the color scheme adoption of smartphone displays [36], or to analyze the oscillation movement of coupled springs [37].

Despite the advances performed on this hardware, its accuracy cannot be compared with the accuracy of dedicated hardware devices [34]. However, the results obtained show that it can be useful in practical cases as in the undergraduate physics laboratory [36] where a high level of accuracy is not needed.

Some operating systems, like Android OS, allow the user to obtain the values from the light sensor through APIs which collect data in the runtime of the application. These APIs will return a single value for each data event [24], whereas most motion and static sensors return a multidimensional array of values.
