The KY-039 Heartbeat Sensor Module is a compact analog pulse detection sensor that measures heartbeats by detecting changes in blood flow through a fingertip. It uses an infrared (IR) LED and a phototransistor to sense variations in light intensity caused by blood circulation.
This module is widely used in Arduino, ESP32, and other microcontroller-based projects, making it ideal for health monitoring systems, fitness trackers, and biometric applications. Its simple 3-pin interface and low power consumption make it beginner-friendly and suitable for portable designs.
 
Specifications
Operating Voltage: 3.3V – 5V DC
Operating Temperature: −40°C to 85°C
Dimensions: ~19 mm × 15 mm
Output Type: Analog signal
Interface: 3-pin (VCC, GND, Signal)
 
Key Features
Analog output for real-time heartbeat signal monitoring
Infrared sensing using IR LED and phototransistor
Compact size for wearable and portable devices
Low power consumption (suitable for battery-powered projects)
Easy integration with Arduino, ESP32, and similar boards