Mobile Sensors — 4th meeting

Nama : Ficky Hardianto
Jurusan : Sistem Informasi — K1
NIM : 185611077
STMIK AKAKOM Yogyakarta

Sensors

The sensor is a device that detects and majors the changes in the nearby environment and sends that data to the operating system or processor. They sense and collects data for which they are made. Like ambient light, the sensor is made for detecting light, so it is an expert in detecting the light.

There are three main categories of sensors that smartphone having.

1. Motion Sensors, These sensors measures axis-based motion sensing, like acceleration forces and rotational forces along with three axes. This category includes accelerometer, gravity sensors, and gyroscopes sensors.
2. Environment Sensors, These sensors measure environmental parameters like air pressure, temperature, light, and humidity, etc. This category includes barometers, photometers, and thermometers.
3. Position Sensors, These sensors measure the physical position of a device. Whether your device is in Landscape mode or Portrait mode or in which direction. This category includes orientation sensors and magnetometers.

Different types of sensors used in smartphones

1. Light sensor, The light sensor can adjust the brightness of the screen according to the environment in which the mobile phone is located at the time, and some can also freely control the light and dark state of the button breathing light.
2. Distance sensor, The distance sensor is typically used in conjunction with a light sensor. When you put your phone in the handset position, the distance sensor measures the distance between the phone and your ear.
3. Gravity sensor, Mobile phone screens are getting bigger and bigger, and the horizontal screen function that was once considered unnecessary is already popular. When we are watching photos and videos, we usually turn the phone over.
4. Acceleration sensor, The concept of an accelerometer is slightly overlapping with the gravity sensor, but in fact it is different. The acceleration sensor is measured in multiple dimensions and mainly measures some instantaneous acceleration or deceleration.
5. Fingerprint sensor, Since 2013, fingerprint sensors have exploded in smartphones. It can automatically collect users’ fingerprints for privacy protection purposes.
6. Gyro sensor, Usually equipped with a three-axis gyroscope in the phone, it can track the displacement changes in six directions. This kind of gyroscope is needed for some shooting or racing games that we play every day.
7. Magnetic field sensor, The magnetic field sensor uses magnetoresistance to measure the plane magnetic field, thereby detecting the strength of the magnetic field and the position of the direction. Generally used in common compass or map navigation to help mobile phone users achieve accurate positioning.
8. GPS position sensor, The main function of the GPS module is to receive satellite coordinate information through the antenna to help the user locate.
9. Air pressure sensor, The air pressure sensor has been used in military mobile phones before, and is divided into a variable displacement air pressure sensor and a variable resistance air pressure sensor. A change in air pressure causes a change in the resistance or capacitance measurement.
10. Temperature Sensor, The temperature sensor is used to detect the temperature change of the mobile phone itself, and the degree of heat generation of the mobile phone can be seen. In terms of extended functions, the temperature sensor can also detect temperature changes in the outside air, even the user’s current body temperature.
11. Hall effect sensor, a Hall effect sensor converts a changing magnetic field into an output voltage, creating a potential difference across the conductor. Some mobile phones will be equipped with some protective covers at random. When the protective cover is closed, the mobile phone will automatically lock the screen. After the protective cover is opened, the device will automatically unlock.
12. Ultraviolet sensor, The ultraviolet sensor uses the photoelectric emission effect to measure, and the outdoor light source is taken by the camera to convert the ultraviolet light intensity into a discharge effect. Mobile phones using such sensors are rare, and the stability of the measurements is subject to further observation.
13. Heart rate sensor, The heart rate sensor is more common in the wearable device, but the application on the mobile phone is generally set at the back of the mobile phone. The high-intensity LED light source illuminates the finger to convert the corresponding data to the heart rate, and the finger needs to be kept stable during the test.
14. Blood oxygen sensor, Like the heart rate sensor, the hemoglobin and oxyhemoglobin in the blood absorb different amounts of infrared light and red light. When the two LED lights of the infrared light and the red light are simultaneously irradiated with the finger, the absorption of the reflected light can also be measured. The spectrum is thus measured for blood oxygen content.