By Jawaaz Ahmed
Today’s smartphones are incredibly tiny machines (this would have seemed like witchcraft a few decades ago). But, we use it for iPhones and Android devices that naturally embrace them, even if they contain so many cool technologies. Take the sensors, for example. Do you know how many different types are in your smartphone?
Let’s start with one of the most commonly used sensors – the accelerometer. As its name suggests, it measures the acceleration that the handset experiences with the freefall. Move it in any direction and the data from this sensor will be pricked, but leave and stay flat. The same sensor is used to determine the orientation of the device along three axes. Applications use this information to tell you whether your phone is portrait or landscape when the screen is facing up or down.
The gyroscope is a sensor that can provide orientation information, but with greater precision. Thanks to this sensor, the function of your Android PhotoSphere camera can tell you how much the phone rotated and in what direction. You can also use the Google Sky Map to tell you the constellation you are pointing at a phone.
Another sensor is that most (if not all) smartphones have now is the magnetometer. Yes, it can detect the magnetic fields. The magnetometer is one of the sensors that control the applications on the planet’s northern pole. Applications for metal detection can also use this sensor.
Nearby is a proximity sensor with infrared LED and infrared light sensor. It is close to the headset of the phone and for good reason – when placing the phone to its ear, the sensor allows the system to be likely to be on call while the screen is to be switched off. The sensor works by invoking the invisible glow of the infrared light of a person, reflecting from a nearby object and receiving the infrared sensor.
The light sensor of the phone measures the brightness of the ambient light. Using the phone’s software, you can automatically adjust the display brightness – if the ambient light is high, the screen brightness rises, and if it is dark, the display fades. Interestingly, the top-of-the-range Samsung Galaxy phones use an advanced light sensor that can be independently measured regardless of white, red, green and blue light. This is no exaggeration. In fact, the Adapt Display function uses this information to fine-tune image representation.
The higher category phones have built-in barometers – with a sensor that can measure atmospheric pressure. The data it measures will determine how high the device is above sea level, which results in better GPS accuracy. According to a related comment, Motorola XOOM and Samsung Galaxy Nexus were among the first Android devices that contained this sensor.
Some people may recall that the Samsung Galaxy S4 thermometer has been extended to measure the ambient temperature. However, there is a thermometer for almost any smartphone, and some devices may have more than one. The difference is that the temperature of the device and the battery are being monitored. If any of the parts overheat, the system stops to prevent injury. And speaking of the Galaxy S4, it has played a pioneering role in using a humidity sensor on smartphones. The data it provided was used in the S Health application to determine whether the user is in the “comfortable zone”, that is, the optimum air temperature and humidity.
While we are on health and fitness, the pedometer is a sensor used to measure the number of user steps. Such data is usually reached by the accelerometer of the device, but the dedicated pedometer is much more accurate and efficient. Google Nexus 5 is one of the few phones that have a real step counter installed.
This list is not complete unless we mention the Galaxy S5 heart rate monitor. As you can tell, pulse measurement is needed and this is accomplished by detecting the momentary pulsation of blood vessels in your finger.
We should also mention fingerprint sensors based on a variety of smartphones, including iPhone 5, Samsung Galaxy S5 and HTC One Max. Of these, the sensor of the 5s is most comfortable to use because no breakthrough is required to read fingerprint data. Fingerprint scanners are most often used as an extra security layer – a substitute for the lock screen password.
Sensors that one cannot expect to find on a smartphone can detect harmful radiation. Yet there is a phone that sports a Sharp Pantone 5. Released only in Japan, it has a dedicated button that launches an application to measure the current radiation level in the area (radiation sensor). Adding a microphone and camera module to the list includes at least 14 sensors that are (or used) on a smartphone. This is quite a lot of data that a smartphone can capture, use and provide. And smart phones are getting more and more awesome for the year, the list is definitely growing steadily.
—The author, from Srinagar, is currently pursuing his M.tech in VLSI Design and Embedded Systems from Visveswaraya Technological University. He can be reached at: [email protected]