“Smartphones are called smart mainly because they have additional properties that traditional communication devices do not have. Smartphones are going further and further on the road to intelligence. We use mobile phones to solve most of the problems on weekdays, such as Internet access, games, navigation, payment, etc., and benefit a lot from it.
Smartphones are called smart mainly because they have additional properties that traditional communication devices do not have. Smartphones are going further and further on the road to intelligence. We use mobile phones to solve most of the problems on weekdays, such as Internet access, games, navigation, payment, etc., and benefit a lot from it.
There are many sensors in the mobile phone that work silently in the background to support our front-end operations. You may just see a bunch of sensor introductions when you look at the parameters of the mobile phone, but do you know what responsibilities these sensors are responsible for?
The powerful performance and integration of mobile SoC chips enable smartphones to obtain stronger computing power, but it is the sensors hidden behind the mobile phone that improve the user interaction experience. Today we will discuss what each sensor in a mobile phone does.
GPS location sensor
The main function of the GPS module is to receive the coordinate information of the satellite through the antenna to help the user locate. With the popularization of 4G network, GPS is used in more scenarios, such as remote positioning monitoring in cooperation with intelligent hardware, or positioning and searching after the device is lost. A concept needs to be distinguished here. Mobile phones are generally equipped with A-GPS. The so-called A-GPS is based on receiving navigation satellite signals through a mobile network for faster positioning, which is more advanced than ordinary GPS.
The distance sensor is usually placed next to the handset of the mobile phone and is used to detect the distance between the front of the mobile phone and other objects. If the distance reaches a threshold, the screen will be automatically turned off, which saves power and prevents the touch screen of the mobile phone from being misused.
Usually the distance sensor is used in two aspects on the mobile phone. First, when making a call, the mobile phone will automatically turn off the screen when it is close to the head to prevent the ear or face from misoperating the touch screen, and turning off the screen during the call can also save power. , the mobile phone will automatically turn on the screen when it is removed from the ear; the second is to prevent the mobile phone from being mis-operated when the screen is on in the pocket or bag.
Air pressure sensor
Air pressure sensors have been used in military mobile phones before, and are divided into variable capacitance air pressure sensors and varistor air pressure sensors. Changes in air pressure can cause the resistance or capacitance measurements to change. Generally, GPS can calculate your position, but for some changes in altitude, a barometric sensor is required to measure. A mobile phone with this kind of sensor installed can measure how many floors you go to in a day, or it can be used for indoor positioning, etc., and the internal air pressure sensor is mainly to test the degree of sealing of the equipment.
Smartphones usually have such a setting – automatic brightness adjustment. When turned on, the phone will automatically adjust the brightness of the phone screen according to the intensity of the surrounding light. In the sunny outdoors, the screen brightness will automatically increase to help people see the screen clearly under strong light; in the dark night, the screen brightness will automatically decrease, reducing the irritation of the light to the eyes, and also saving electricity by the way. The light sensor is used to sense the intensity of the surrounding light to automatically adjust the brightness of the mobile phone screen.
The light sensor and the distance sensor are often integrated in one location, which can reduce the opening of the front panel and make the design better. The well-known Hammer mobile phone has integrated the light sensor, distance sensor and mobile phone receiver into a long opening since the T1, and the front panel is more uniform.
Many smartphones are equipped with temperature sensors, and some have more than one. The difference is that their purpose is to monitor the temperature inside the phone as well as the battery. If a component is found to be overheated, the phone will shut down to prevent damage to the phone. In terms of extended functions, the temperature sensor can also detect temperature changes in the outside air, and even the user’s current body temperature.
The ultraviolet sensor uses the photoemission effect to measure and measure the ultraviolet intensity by shooting the outdoor light source through the camera and converting it into the discharge effect. There are not many mobile phones using this kind of sensor now, and the stability of the calculation needs to be further observed. The photoemission effect of certain semiconductors, metals or metal compounds releases a large number of electrons under ultraviolet irradiation, and the ultraviolet intensity can be calculated by detecting this discharge effect. The main use is also in the field of sports and health. Detects radiation levels in the environment.
The sensor output current is proportional to the light intensity, and the product output has a very high consistency. The sensor has a specific spectral response. This product is mainly for ultraviolet measurement in sunlight and UVA lamp intensity measurement. It is mainly used in mobile phones, smart wearable devices, UV lamp monitoring and other fields.
Above we have listed the more mainstream sensors in smartphones, most of which have become standard features of smartphones. We can classify these sensors into categories. For example, some are for basic function detection, such as light distance sensors; some are used for navigation measurement, such as GPS and magnetic field sensors; others are dedicated to sports health, such as heart rate and blood pressure. Oxygen sensor, UV sensor, etc. It is these “black technologies” hidden behind mobile phones that make us more handy when using smartphones.
Sensors, like other Electronic components, are getting smaller and cheaper these days. In the future, the development direction of mobile phone sensors will be to think about how to further improve the precision of measurement and calculation, and how to integrate more sensors in limited devices to sense the current state of users.