Hello everyone!

I have successfully completed the Real-Time Heart Rate Monitor project for my YouTube channel, EC TUTO.

How It Actually Works (Photoplethysmography): Before sharing the build video, I wanted to quickly document the science behind how this little sensor reads a heartbeat. The project relies on a medical technique called Photoplethysmography (PPG):

• The Light: The Pulse Sensor has a tiny green LED that continuously shines light into the tissue of your finger.
• The Blood Flow: Every time your heart pumps, a fresh wave of blood rushes through your capillaries.
• The Detection: Blood naturally absorbs green light. During a heartbeat, more blood is present, meaning less light reflects back to the sensor's photodetector.
• The Output: The Arduino measures these microscopic changes in reflected light. Then, the Processing software translates this raw analog data into a real-time heartbeat graph!

It is incredibly rewarding to see this biological data turned into a beautiful, red ECG-style graph on the computer screen rather than just reading raw numbers on a serial monitor.

I documented the entire assembly process in a clean, satisfying ASMR format. You can sit back, relax, and watch the full build here:

📺 Watch the video:

All the source codes (.ino and .pde files) and the components list are already detailed on the main project page. If you have any questions, let me know in the comments. Happy making!