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