Importance of Smartphone Sensors in Near Future

Mobile phone becomes very smart when there will be more sensors are present in it. Let’s now talk about different sensors are used in mobile phones.

Magnetometer

The magnetometer sensor in your tablet or smartphone also utilizes the modern solid state technology to create a miniature Hall-effect sensor that detects the Earth's magnetic field along three perpendicular axes X, Y and Z.

The Hall-effect sensor produces voltage which is proportional to the strength and polarity of the magnetic field along the axis each sensor is directed. 

The sensed voltage is converted to digital signal representing the magnetic field intensity. 

Other technologies used for magnetometer may include magneto resistive devices which change the measured resistance based on changes in the magnetic field.

The magnetometer is enclosed in a small electronic chip that often incorporates another sensor (typically a built in accelerometer) that helps to correct the raw magnetic measurements using tilt information from the auxiliary sensor.

In addition to general rotational information, the magnetometer is crucial for detecting the relative orientation of your device relative to the Earth's magnetic north.

E-compass is based on magnetometer sensor used in mobile phones and tablets for alignment of display with the user’s orientation. 

Phone always knows about the North direction so that it can auto rotate your digital maps

according to our physical orientation.

Proximity Sensor

A proximity sensor is a sensor able to detect the presence of nearby objects without any physical contact. 

A proximity sensor often emits an electromagnetic field or a beam of electromagnetic radiation (infrared, for instance), and looks for changes in the field or return signal.

Today, mobile phones use IR-based proximity sensors to detect the presence of a human ear. 

This sensing is done for two purposes: Reduce display power consumption by turning off the LCD backlight and to disable the touch screen to avoid inadvertent touches by the cheek.

IR sensors have a number of disadvantages, including high power consumption, high cost, blind zones, and accumulation of dirt, as well as unreliable performance over temperature, hair, and skin color variations.

Recent advances in capacitive proximity sensing technology address these designs disadvantages and could potentially replace every IR sensor in the mobile phone market.

The sensor works by shining a beam of invisible to human’s infrared light which is reflected from a nearby object and picked up by the IR detector.

Accelerometer

Actually a smart device with accelerometer is nothing but a circuit based on MEMS(Micro Electro Mechanical System), that senses or measures the forces of acceleration that may be caused due to gravity of movement or tilting action. 

So, it is a device to measure the speed of acceleration or movement to which it is attached. If it is employed in mobile, it will do accordingly. 

It also senses the the angle at which it is being held via mobile.

 

Advantages

1.   It changes/adjusts the screen to proper viewing, when user changes the orientation from horizontal/landscape to vertical/portrait and vice-versa.

2.   It interacts or controls the racing games (motion sensitive) by changing the direction or steer of the racing vehicle.

3.   It helps the user to mute the phone/device in case of incoming call or when music is played, just by turning the device facing downward.

4.   It makes web-browsing and photo viewing better by changing the orientation.

 

Gyroscope

Gyroscopes, or gyros, are devices that measure or maintain rotational motion. 

MEMS (microelectromechanical system) gyros are small, inexpensive sensors that measure angular velocity. 

The units of angular velocity are measured in degrees per second (°/s) or revolutions per second (RPS).

The gyroscope is a sensor that can provide orientation information as well, but with greater precision. 

Thanks to this particular sensor, Android's Photo Sphere camera feature can tell how much a phone has been rotated and in which direction. 

It is also used by Google's Sky Map for telling what constellation you're pointing a phone at.

1.   You cannot play a game that involves circular motion for instance counter strike.

2.   Without gyroscope Orientation of the phone Horizontal and vertical orientation of the device may not be sensitive.

3.   Your smartphone is unable to measure the tilt angle.

4.   Accelerometer alone will not provide orientation of the smartphone precisely without the help of gyroscope.

5.   Images in your phone cannot be viewed in tilt because of no gyroscope.

6.   You cannot use applications that works based on gyroscope.

Hope you understand!

Ambient Light Sensor

Ambient light sensors are used as backlighting controls in any number of LCD display applications from consumer electronics to automotive, and by automatically adjusting display brightness, they can conserve battery life, which is a key benefit in mobile device applications.

The ambient light sensor adjusts the brightness of your display according to the external environment.

Barometer

1.   Measures air pressure.

2.   Weather forecasts- While we do have those now even without barometers in our phones, barometers can help the device provide a much more accurate, up to the minute weather forecast. Atmospheric pressure paired with the general forecast for the air can warn of you upcoming rains and such, minutes in advance. Also, what works one way, can work the other way too – hundreds of thousands or even millions of devices with barometers spread across the globe could help distributed data collection on atmospheric pressure and its changes, thus improving weather forecasts for everyone.

3.   Warning system- Atmospheric pressure change warnings. This is somewhat related to the previous point. Many people, especially older ones, and people with a variety of health conditions, are very sensitive to the changes of the atmospheric pressure. Some need to take certain pills, others need to lay down. Now, the mobile phone will be able to warn them slightly in advance.

4.   Positioning- Most smartphones these days are equipped with GPS. GPS can tell the altitude as well, but it is not very accurate at it. Barometric sensor can improve that a lot. Practical applications can vary from sports like parachuting and paragliding, through hobbies like remote control airplanes, to navigation and location service inside buildings (which floor am I at?).

Temperature Sensor

It is used to measure the temperature of the atmosphere around the smartphone. Measures CPU and Battery temperature and display that data.

If a component is detected to be overheating, the system shuts itself down to prevent damage. 

And speaking of the Galaxy S4, it pioneered the use of an air humidity sensor in a smartphone. 

Data provided by it was used in the S Health application to tell whether or not the user was in their "Comfort Zone" – one with optimal air temperature and humidity.

In this way, sensors are very important in a smartphone because they monitor various activities and send data to make your lives easy and happy.