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All the Sensors you have inside your Mobile Phone – a brief overview

All the Sensors you have inside your Mobile Phone – a brief overview
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3. GPS or Global Positioning System

Global Positioning System (GPS) technology has vast application in the technology sector. Traditionally, everyone relied on physical maps to get direction. Hikes and road trips were often characterised with stop overs to read maps and consult compasses to figure out where one was. Often people got lost and took many hours to get back on track. GPS turned that sad state of affairs on its head. GPS systems have made it possible for smartphone users to tell exactly where they were at a point in time. How it works is not rocket science.

A GPS unit inside a smartphone will get a ping from a satellite all the way up in space to figure out which sector of the planet you are driving through or standing on. Contrary to popular belief, GPS does not use mobile data at all. The phone itself may use cellular information to work out location fully independent of GPS. This is done by calculating the distance to cell towers and coming up with a rough estimate of one’s location. The beauty of GPS not relying on mobile network is that a user is able to find their location even in areas where there is no signal reception. GPS connects with several satellites to calculate where a user is based on the angles of intersection. Pin pointing location comes down to use of longitudes and latitudes as markers.


GPS may struggle indoors or during heavy cloud cover. This is because GPS would not be able to establish a lock. A GPS lock is required to pinpoint a location. A lock requires communication with at least four satellites in good view to establish accurate position.

GPS should be used with care as it takes a heavy toll on battery life very fast.

4. Magnetometer

This sensor also aids with working out where a phone is in physical space. It measures magnetic fields as the name suggests. It gives compass direction using the cardinal points.

For its primary purpose of finding location, it works in tandem with data coming from the GPS and the accelerometer to establish which direction you are pointing and your location in the world.

5. Proximity Sensor

The proximity sensor is able to detect the presence of any nearby objects without requiring any physical contact with the them. On smartphones, the sensor is typically located near the top ear piece. It uses a light detector and infrared LED to establish whether you have the mobile device up to your ear. If that is the case it disables the touch screen to prevent inadvertent operation of the phone by the cheek. Light used for this purpose is not visible to the human eye.

Though this sensor is quite useful, it has several shortcomings. Dirt easily accumulates over the sensor due to its positioning, unreliable performance over skin colour, temperature and hair variations.

6. Fingerprint Sensor

Finger print sensors have only recently been built into smartphones. They offer a new layer of security by authenticating a user before they are able to gain access to a smartphone. It can be used to unlock a phone from the lock screen or even encrypt data on a smartphone. The iPhone 5S, HTC One Max and the Samsung Galaxy S5 are examples of smartphones that have fingerprint sensing technology.


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