【Acts Like a Microphone】Used to receive sound waves, display vibration images of sound, but cannot measure the intensity of noise. | 【Working Principle】The sensor has a capacitive electret microphone that is sensitive to sound. Sound waves cause the electret film inside the microphone to vibrate, resulting in a change in capacitance and a small voltage corresponding to the change. This voltage is then converted into A 0-5V voltage, which is accepted by the data collector through A/D conversion and transmitted. | 【Specifications】50Hz-15KHz. Three digital pins: Clock, Data and Left-Right (Word Select) Clock. | 【Note】This I2S MEMS microphone is bottom ported, so make sure you have the hole in the bottom facing out towards the sounds you want to read. It's a 1.6-3.6V max device only, so not for use with 5V logic.

【Pulse Oximeter】A pulse oximeter measures the saturation of blood oxygen in the bloodstream. | 【Health Monitoring Indicator】Oxygen saturation can reflect early medical problems such as the heart and lungs, this reading is useful as a general health monitoring indicator. | 【Working Principle】 Oxygenated hemoglobin absorbs more infrared light than red light, while deoxyhemoglobin absorbs more red light than infrared light. Therefore, the red and infrared leds in the oximeter alternately emit light, and the photodiode receives the light signal that is not absorbed. The ratio of red and infrared light received by the photodiode is used to calculate the percentage of oxygen in the blood. | 【Addition】According to the pulsation characteristics of the arterial blood flow, the pulse rate and intensity are also determined during the measurement.