1. Ambient Light Sensor

The light sensor is similar to the eyes of a mobile phone. The human eye can adjust the light entering the eye in different light environments, such as entering a movie theater, and the pupil will be enlarged to allow more light to enter the eye. The light sensor allows the phone to sense the intensity of the ambient light and adjust the brightness of the phone screen. And because the screen is usually the most power-hungry part of the phone, using a light sensor to help adjust the brightness of the screen can further extend battery life. The light sensor can also be used with other sensors to detect if the phone is placed in a pocket to prevent accidental touch.

2, proximity sensor

The infrared light is emitted through the infrared LED lamp, and is reflected by the object and then received by the infrared detector, thereby judging the intensity of the received infrared light to determine the distance, and the effective distance is about 10 meters. It can sense whether the phone is attached to the ear to talk on the phone, if it will turn off the screen to save power; the distance sensor can also be used in the glove mode supported by some phones to unlock or lock the phone.

3, G-Sensor

Realized by the piezoelectric effect. Inside the gravity sensor, a weight is integrated with the piezoelectric piece, and the horizontal direction is calculated by the magnitude of the voltage generated by the orthogonal directions. When used in a mobile phone, it can be used to switch between horizontal and direct screen. When used in a racing game, it can be used in the game by horizontal sensing to rotate the driving direction.

4, Accelerometer Sensor

The principle of action is the same as that of the gravity sensor, but the acceleration direction is determined by three dimensions, and the power consumption is small but the precision is low. It can be used in mobile phones to count steps and judge the direction of the phone.

5, Magnetism Sensor

Measuring the change of resistance to determine the strength of the magnetic field, you need to shake the phone to accurately judge when using, mostly used in compass, map navigation.

6, Gyroscope

The gyroscope is capable of measuring angular velocity along one or several axes and is ideal for complementing the capabilities of MEMS accelerometers (acceleration sensors). In fact, if combined with accelerometers and gyroscopes, system designers can track and capture the full motion of 3D space, providing end users with a more realistic user experience, precise navigation system and other features. The "shake" function in the mobile phone (such as shaking the mobile phone can draw lots...), somatosensory technology, and the adjustment and detection of the VR angle of view are all applied to the gyroscope.

7, GPS

There are 24 GPS satellites running on a specific orbit above the Earth, and they will constantly broadcast their location coordinates and timestamps around the world (TImestamp, referring to Greenwich Benz 1970 Jan 01 00 00 00 seconds to the present The total number of seconds so far, the GPS module in the mobile phone starts from the instantaneous position of the satellite, and calculates the distance between the mobile phone and the satellite by the time difference between the time of the satellite transmission coordinates and the time of reception. Can be used in positioning, speed measurement, measuring distance and navigation.

8, fingerprint sensor

At present, the mainstream technology is a capacitive fingerprint sensor, but the ultrasonic fingerprint sensor has also become popular. When a capacitive fingerprint sensor is used, the finger is a pole of the capacitor, and the other pole is an array of silicon chips. The micro-current generated between the micro-electric field and the capacitive sensor carried by the human body, the peak wave trough between the fingerprint and the sensor The distance is formed by the capacitance difference to describe the pattern of the fingerprint. The principle of ultrasonic fingerprint sensor is similar, but it will not be interfered by sweat and oil, and the recognition speed is also faster. It can be used in mobile phones to unlock, encrypt, pay, etc.

9, Hall Sensor

The principle of action is the Hall magnetoelectric effect. When a current passes through a conductor in a magnetic field, the magnetic field produces a force perpendicular to the direction of electron motion for the electrons in the conductor, thereby creating a potential difference across the conductor. Mainly used in the function of flip unlocking, closing the lock screen, etc., Apple's Smart cover and several brands of official mobile phone accessories, all use this technology.

10, air pressure sensor (barometer)

Connecting the membrane to a transformer or capacitor, when the air pressure changes, causes a change in the value of the resistor or capacitor, thereby measuring the pressure data. GPS can also be used to measure altitude but there will be an error of about 10 meters. If the air pressure sensor is equipped, the error can be corrected to about 1 meter. It can also be used to assist GPS positioning to confirm the location of the floor. Apple's iPhone 6/6s series are equipped with air pressure sensors.

11, heart rate sensor

When the finger is illuminated by a high-intensity LED lamp, the brightness (the depth of the red light) changes periodically as the heart pushes the blood to the capillaries. Then capture these regular changes through the camera, and transfer the data to the mobile phone for calculation, and then determine the contraction frequency of the heart, and get the number of heart beats per minute.

12, blood oxygen sensor

Hemoglobin and oxyhemoglobin in the blood have different absorption ratios for red light. The infrared light and the red LED are simultaneously irradiated to the finger, and the absorption spectrum of the reflected light is measured, thereby measuring the blood oxygen content. Can be used in sports or health applications.

13, UV sensor

The photoelectric emission effect of certain semiconductors, metals or metal compounds releases a large amount of electrons under ultraviolet irradiation, and the ultraviolet intensity can be calculated by detecting such a discharge effect. The main use is also in the field of sports and health.