I was fascinated by the pulse sensor's ability to measure heart rate. While researching it, I became curious about the type of sensor my Apple Watch used and how it measures my heart rate, so I looked it up and discovered that it uses an optical heart sensor. I realized that an optical heart sensor and a pulse sensor are related in that they both serve to measure aspects of the cardiovascular system, but they differ in their scope and the specific measurements they provide. This led me to decide to do research on both sensors together.
https://www.sparkfun.com/products/11574
Pulse sensors are non-invasive electronic devices that measure the number of times the heart beats per minute. They are simple to use, requiring only your fingers to be placed on your wrist or the side of your neck. Pulse sensors also sip power, with a current draw of just 4mA at 5V, making them ideal for mobile applications.
The Pulse Sensor has three pins: