Update: 2019-08-19 14:38 Source: LUFTMY
With the development of mobile technology, smart watches have become more and more popular. In addition to indicating the time, smart watches also have many functions such as navigation, reminder, detection and call.These smartwatches use a variety of sensors.
Different functions are realized by different sensors, such as monitoring heart rate, monitoring sleep, sports reminder, GPS positioning and so on. So what kinds of sensors are used in smartwatches?
Vital signs sensors are used to monitor blood pressure. Its working principle is based on photoelectric volumetric pulse wave (PPG).Pulse rates are measured by light from blood vessels, which dilate and contract as blood pulses pass through them.Be able to analyze and synchronize heart rate measurements (HRP) and ECG measurements (ECG) to calculate the high and low values of blood pressure.
Ambient light sensor for LED display, can automatically adjust the brightness of the display, saving the watch battery.The ambient light sensor can perceive the surrounding light condition, automatically adjust the brightness of the display screen by processing chip, and reduce the power consumption of the product.The ambient light sensor is divided into three parts: the light sensor for detecting the ambient light intensity, the data processing device, and the actuator for controlling the backlight input current.
Smartwatches rely on NFC functions for payment terminals, subway ticket gates and other NFC card reader devices.
The smart watch can detect the ambient temperature and humidity. The sensor's relative humidity and ambient temperature reading can help improve the accuracy and reliability of the body movement measurement which is highly dependent on the environmental conditions.