Arduino-Powered Heart Rate Sensor Competition Set for 2025
=========================================================================================
In this article, we'll guide you through the process of creating a heart rate sensor for the One Hertz Challenge using a Wemos D1 mini, a MAX30102 heart rate sensor, and pulse oximetry. This project showcases the ease of picking up biometric data using a capable microcontroller and off-the-shelf sensors.
Hardware Setup
To get started, connect the MAX30102 sensor to the Wemos D1 mini. The MAX30102 uses LEDs (red and infrared) and a photodetector to measure blood oxygen saturation and pulse rate by detecting changes in light absorbance through a finger or earlobe. Ensure proper wiring for power (3.3V or 5V depending on sensor specifications), ground, and I2C communication lines (SCL, SDA) between the MAX30102 and the Wemos D1 mini.
Software and Firmware Setup
Use an Arduino IDE or similar environment compatible with ESP8266 to program the Wemos D1 mini. Include libraries for handling the MAX30102 sensor and for data processing of pulse and SpO2 readings. Implement code to read raw sensor data, filter noise, and calculate pulse rate (in beats per minute and Hertz).
Pulse Rate Measurement and Display
The sensor detects the change in infrared light absorption corresponding to blood volume changes with each heartbeat. The Wemos D1 mini processes these signals and converts them into pulse rate data. Connect a small OLED display to the Wemos D1 mini to show output values, including heart rate in beats per minute and frequency in Hertz (heartbeats per second).
Calibration and Testing
Calibrate the sensor readings to improve accuracy. Test the device by placing a finger on the sensor and verify that heart rate values update correctly on the OLED display.
One Hertz Challenge Context
The One Hertz Challenge highlights detecting a heart rate of exactly 60 bpm, which equals 1 Hz, representing one beat per second. This is where the sensor and processing enable real-time heart rate display down to Hertz precision.
Summary Table
| Step | Description | |----------------------|-------------------------------------------------------------------------------------------------| | Hardware wiring | Connect MAX30102 sensor to Wemos D1 mini via power, ground, I2C (SCL, SDA) | | Firmware programming | Use Arduino IDE with appropriate libraries to read and process sensor data | | Signal processing | Calculate heart rate (bpm and Hz) from sensor light absorption changes | | Display output | Output heart rate values on connected OLED display | | Calibration/testing | Validate readings by testing sensor on finger and tuning code | | Challenge relevance | Achieve and detect heart rate = 60 bpm (1 Hz) for the One Hertz Challenge |
This approach is based on [Ludwin]’s 2025 One Hertz Challenge project that uses the MAX30102 with a Wemos D1 mini, leveraging pulse oximetry principles to output heart rate and pulse frequency on an OLED screen, showcasing how accessible biometric sensing has become with off-the-shelf components and microcontrollers[2].
Pulse oximetry is a method that determines the oxygenation of blood by measuring its absorbance of red and infrared wavelengths, usually done by passing light through a finger. The average resting heart rate is often around 60 bpm. The build is based on a Wemos D1 mini, an ESP8266 development board.
- This project, using open source hardware like the Wemos D1 mini and the MAX30102 heart rate sensor, is a DIY approach for creating a heart rate sensor that follows the principles of pulse oximetry.
- The Arduino IDE, being compatible with ESP8266, is used to program the Wemos D1 mini, allowing it to read and process data from the MAX30102 sensor.
- The heart rate sensor, powered by the Wemos D1 mini, uses sensors and technology to detect changes in light absorbance through a finger or earlobe, delivering health-and-wellness data such as heart rate, potentially useful in fitness-and-exercise wearables and gadgets.
- With the correct wiring for power, ground, and I2C communication lines, the MAX30102 sensor works in sync with the Wemos D1 mini, offering an open source and affordable solution for biometric data acquisition.
- This project showcases the accessibility of biometric sensing in the realm of science and technology, highlighting the potential for DIY projects to contribute to health-related monitoring and fitness technology using off-the-shelf components and microcontrollers.
