The KY-039 Heartbeat Sensor Module is a compact, analog sensor designed to detect heartbeats by measuring changes in blood flow through a fingertip. Utilizing an infrared (IR) LED and a phototransistor, this module is ideal for integration with microcontrollers like Arduino and ESP32 for health monitoring projects, fitness trackers, and biometric applications.

Features :

• Analog Output: Provides a continuous analog voltage corresponding to the heartbeat signal.
• Infrared Sensing: Employs an IR LED and phototransistor to detect variations in light intensity caused by blood flow.
• Compact Design: Small form factor (approximately 19mm x 15mm) suitable for wearable and portable applications.
• Low Power Consumption: Operates efficiently within a voltage range of 3.3V to 5V.

Specifications :

• Operating Voltage: 3.3V to 5V DC
• Operating Temperature Range: -40°C to 85°C
• Dimensions: Approximately 19mm x 15mm
• Output Type: Analog voltage signal
• Interface: 3-pin header (VCC, GND, Signal)
• Pin Configuration
  • VCC: Connect to 3.3V or 5V power supply
  • GND: Connect to ground
  • Signal (S): Analog output to be connected to an analog input pin on the microcontroller 

Usage Tips :

• Finger Placement: Ensure the finger is properly positioned between the IR LED and phototransistor for accurate readings.
• Ambient Light: Minimize exposure to ambient light to reduce interference. Consider enclosing the sensor or using it in a controlled lighting environment.
• Signal Processing: Implement filtering techniques in software to smooth out the analog signal and accurately detect heartbeats.

DataSheet : KY-039 Heartbeat Sensor Module Datasheet (PDF)