Here in the era of modern technology we use smartphones, Laptops, gaming consoles and many more electronic gadgets. The most common thing we find in everybody’s pocket is a smartphone. As technology keeps on advancing we are able to use wonderful features by using it. We all are carrying a mini PC in our pockets. A mobile phone is just a hand held device which is used to make calls and text messages. But in a smartphone there are many advanced features which makes our lives easy. In a smartphone,the brightness sets automatically, has a compass, turns off the display when we put our phone on the ear while calling, etc., are can be done. All these operations are done with the help of specific sensors. Different sensors are responsible for different functions.
Sensors Used in Mobiles
In this article we are going to discuss about the types of sensors used in smartphones.
Proximity sensor is placed near the earpiece of the mobile. It is able to detect the near by objects without any physical contact. It consists of Infrared LED and IR light detector. The IR LED emits the invisible light and when the light is reflected, the IR light detector detects the reflected light and the system will know that there is an object nearby. Thus the software is programmed that the device screen turns off when the IR detector detects the reflected light. When we place the mobile up to ear, it turns off the display knowing that we are on a call and to avoid accidental touches on the screen.
Ambient Light Sensor
The sensor detects the amount of light around the device. Basically Ambient Light Sensor is used to set automatic brightness in the device. When the ambient light is more the display brightness increases and when it is dark display brightness decreases. Generally we find both proximity and ambient light sensors are integrated.
Accelerometers can determine the orientation of the device. It senses the change in orientation by 3D measurement of acceleration of the device relative to the free fall. The data helps the phone’s software that in which direction the phone is and rotates the screen accordingly. This sensor/feature is used in camera, games and many other applications.
Gyroscope is the sensor that gives orientation information as well but with greater precision. The data from this sensor can tell the exact position and angle of the device. Basically this sensor is used for Virtual Reality (VR) applications. We can enjoy all the VR applications and 360° videos in the device which has a gyroscope sensor.
Global Positioning System (GPS)
GPS is used by most of the smartphone users. It works in any type of weather conditions. GPS receiver track the location of the device. There are many applications to navigate from one place to another place and we can use GPS to know where we are.
Barometer measure the atmospheric pressure i.e., data measured by it is used to determine how high the device is above sea level. This improves accuracy of GPS.
There is a thermometer in most of the smartphones which can detect the temperature inside the device. This is present because any mobile if there is a problem with the processor or battery which gets overheated and the device is turned off to avoid damages. Some devices has two of them to measure the ambient temperature.
Magnetometer is nothing but a digital compass which shows the directions.
Touch screens are also type of sensors that can accept input from the user by touching it.
The detailed description of touch screen is given in this article: Working and Types of Touch Screens
Heart Rate Monitor
This sensor measures the pulse and it does that by detecting the number of pulsations per minute of the blood vessels inside the user’s finger. Samsung Galaxy S5 is one of the devices which has heart rate monitor.
Finger Print Sensor
Finger Print Sensors are used for additional security purpose to a smartphone. The user can set his/her finger print to access the device without typing any passwords. The first smartphone to have finger print scanner is Motorola Atrix in 2011 and later other manufacturers has added it.
Iris scanner is also used for additional security purpose. It has infrared LED and Iris camera in which the IR LED is turned on when the user is trying to setup, then the iris camera could capture the iris pattern and store it in the device. While unlocking the phone the device could automatically recognizes the person’s iris and phone unlocks. The first smartphone to have iris scanner is ARROWS NX F-04G which is from a Japan based company Fujitsu. Later Microsoft launched Lumia 950 and Lumia 950XL with iris scanner.
This is different from all the sensors discussed in this article. Sensor Core is developed by Nokia exclusively for Windows Phones. It Collects the data from already existing sensors in the device so that the user can see how far he/she traveled, how many steps taken, how many calories were burned, and how long it took to complete the workouts. It is based on both hardware and software in which the hardware is a physical buffer between the available sensors in the device like GPS, accelerometer, compass,etc. The software enables to collect data and makes the user easier to look after it.