The Heart Beat Sensor (often called a Pulse Sensor or Heart Rate Sensor) is a biomedical device used to measure the pulse rate (BPM – Beats Per Minute) by detecting changes in blood flow. It is commonly used with microcontrollers like Arduino or ESP boards in health monitoring projects. 🔹 Working Principle The sensor uses a photoplethysmography (PPG) method. It has a light source (usually an LED) and a light detector (LDR or photodiode). When the sensor is placed on a fingertip or earlobe, blood flow changes with each heartbeat. These changes affect how much light is absorbed or reflected. The detector senses these changes and converts them into an electrical pulse signal. The signal is amplified and filtered to remove noise, then sent to the microcontroller. 🔹 Components of a Typical Heart Beat Sensor LED (infrared or green) → shines light through the skin. Photodiode/Photoresistor → detects reflected/transmitted light. Amplifier & Filter Circuit → removes noise and strengthens signal. Output Pin → sends digital/analog pulses to the microcontroller. 🔹 Pin Configuration VCC → Power supply (3.3V – 5V). GND → Ground. Signal Out → Pulse signal output (analog or digital depending on design). 🔹 Applications Heart rate monitoring (fitness trackers, smartwatches). Health monitoring systems (IoT healthcare). Sports and fitness applications. Stress detection and meditation devices. Biomedical and educational projects. 🔹 Advantages Simple and non-invasive. Low-cost and easy to use with Arduino. Real-time monitoring possible.