How to Use KY-039: Examples, Pinouts, and Specs

The KY-039 Heartbeat Sensor Module by JOY IT is a compact and versatile sensor designed to detect the pulse rate of an individual. It operates by sensing the change in blood volume in a fingertip or earlobe through a photoplethysmograph approach. The module is commonly used in health monitoring devices, fitness trackers, and interactive projects that require pulse detection.

• Personal health monitoring
• Fitness and wellness devices
• Biofeedback systems for relaxation or stress management
• Educational projects to demonstrate biometric sensing

• Operating Voltage: 3.3V to 5V DC
• Output Type: Analog voltage signal corresponding to the heartbeat
• LED Indicator: Indicates heartbeat detection

1. Connect the + pin to the 3.3V or 5V output on your microcontroller (e.g., Arduino UNO).
2. Connect the - pin to the ground (GND) on your microcontroller.
3. Connect the S pin to an analog input on your microcontroller.

• Ensure that the sensor is firmly attached to the skin without any movement, as motion artifacts can cause inaccurate readings.
• Avoid exposing the sensor to direct sunlight or strong artificial light sources, as this can interfere with the sensor's operation.
• Use a stable power supply to prevent fluctuations that could affect the sensor's accuracy.

// KY-039 Heartbeat Sensor Example Code
const int heartbeatPin = A0; // Analog pin connected to the heartbeat sensor
int sensorValue = 0;         // Variable to store the sensor value

void setup() {
  Serial.begin(9600);        // Initialize serial communication at 9600 baud
}

void loop() {
  sensorValue = analogRead(heartbeatPin); // Read the sensor value
  Serial.println(sensorValue);            // Print the sensor value to the serial monitor
  delay(100);                             // Wait for 100 milliseconds before the next read
}

• Inconsistent Readings: Ensure that the sensor is properly attached to the skin and that there is minimal movement.
• No Readings: Check the connections to the microcontroller and ensure that the power supply is within the specified range.
• LED Not Lighting Up: Verify that the LED is functional and that the sensor is receiving power.

• If the sensor is not responding, try adjusting the position on the finger or earlobe to find a spot with better pulse detection.
• Use a multimeter to check the voltage across the power supply pins to ensure it is within the specified range.
• Check the analog pin connection on the microcontroller to ensure it is receiving the signal from the sensor.

Q: Can the KY-039 sensor be used on any part of the body? A: The sensor is optimized for use on the fingertip or earlobe where the pulse is more easily detected.

Q: How accurate is the KY-039 sensor? A: The accuracy can vary based on several factors, including sensor placement and environmental conditions. It is suitable for educational and hobbyist projects but not for medical diagnosis.

Q: Can the sensor work with a 3.3V system? A: Yes, the KY-039 can operate with a 3.3V power supply, making it compatible with both 5V and 3.3V microcontrollers.

Q: Is calibration required for the sensor? A: No specific calibration is required, but you may need to adjust the threshold in your code based on the analog signal range you observe during testing.

This documentation provides a comprehensive guide to using the KY-039 Heartbeat Sensor Module with an Arduino UNO or similar microcontroller. For further assistance, consult the manufacturer's datasheet or contact technical support.