how-to-design-a-heart-rate-pulse-sensor-bpm-meter

As health and wellness become increasingly important, the ability to monitor vital signs, such as heart rate, is more valuable than ever.

In this circuit design, we’ll build a heart-rate pulse sensor BPM (beats per minute) meter using an OLED display and the widely available Arduino UNO microcontroller.

Figure 1. A prototype of the heart rate sensor using Arduino UNO.

Understanding the project

Before we begin, it’s helpful to understand the concept behind a heart-rate pulse sensor BPM meter. A pulse sensor works by detecting changes in blood volume within a vessel, which correspond to the rhythmic pumping of the heart. These fluctuations (known as pulse waves) form the basis for measuring heart rate.

The goal of this project is to develop a portable, user-friendly device that displays real-time heart rate data.

Components

To build the heart-rate pulse sensor BPM meter, you’ll require the following:

Arduino UNO – The main microcontroller board used for programming and processing
OLED display – A compact, high-contrast screen to show heart rate readings and related data
Pulse sensor – Detects blood volume changes in the fingertip to measure heart rate
Jumper wires – Used to connect components on the breadboard
Breadboard – Provides a platform for easy circuit prototyping
USB cable – For powering and programming Arduino UNO
Computer or laptop – Required to upload code and interface with Arduino

Building the circuit

Follow these steps to assemble the heart-rate pulse sensor BPM Meter circuit:

1. Connect the pulse sensor’s:

Signal pin to Arduino’s analog pin A0
VCC pin of Arduino’s 5V pin
GND pin to Arduino’s GND pin

2. Connect the OLED display’s:

VCC pin to Arduino’s 5V pin
GND pin to Arduino’s GND pin
SCL pin to Arduino’s analog pin A5
SDA pin to Arduino’s analog pin A4

3. Connect Arduino UNO to:

A computer or laptop using a USB cable to supply power and upload the code.

Figure 3. A circuit overview.

Coding the meter

Now, let’s program Arduino UNO to read data from the pulse sensor and display the heart rate on the OLED display.

To do so, follow these steps:

Install the required libraries for both the OLED display and the pulse sensor using Arduino’s IDE’s Library Manager.
Write the code to read the analog signal from the pulse sensor, process the data to calculate beats per minute (BPM), and display the result on the OLED screen.
Connect Arduino UNO to your computer using a USB cable.
In the Arduino IDE, select the correct board and port from the Tools menu, then click the Upload button to upload your code.

Testing and calibration

After uploading the code, place your fingertip on the pulse sensor and observe the OLED display. You should see your heart rate in real time, measured in beats per minute (BPM). Adjust the sensor’s position or sensitivity if the readings appear unstable or inaccurate.

Figure 3. A fully assembled and tested heart rate sensor circuit.

Conclusion

Building a heart-rate pulse sensor BPM meter with an OLED display and Arduino UNO is a hands-on way to explore personalized health monitoring. Whether for fitness tracking, wellness education, or learning about bio-signals and microcontrollers, this project combines healthcare and technology in a meaningful and accessible form.