Most modern monitors use one of two primary technologies to detect your pulse:
For those interested in electronics, building a heart rate monitor is a popular beginner-to-intermediate project. Enthusiasts often use an Arduino paired with a pulse sensor to display live data on an LED screen or serial monitor. Some even utilize smartphone cameras and flashes as makeshift optical sensors to extract pulse data through Python processing.
Monitoring your resting heart rate (RHR) over time can indicate how well your body is recovering from stress or illness. DIY and Custom Projects