This project is a BPM (Heart Rate) Monitoring System made with an Arduino Nano, a Pulse Sensor, and an OLED (SSD1306) display. It measures your heart rate in real time and shows the BPM clearly on the screen.

To make the project look neat and interesting, the whole system is housed in a custom 3D-printed heart-shaped case. This design is ideal for science fairs, DIY projects, and student demonstrations.

This build is beginner-friendly, easy to assemble, and serves as a great introduction to electronics and basic biomedical sensing.

Supplies

Electronics

1. Arduino Nano
2. Pulse Sensor
3. OLED Display (SSD1306, I2C)
4. Jumper Wires
5. Mini Breadboard

Power

1. 5V USB cable
2. OR
3. 5V rechargeable battery pack

Step 1: 3D Printing the Case ❤️🖨️

1. Download the heart-shaped enclosure STL files from Thingiverse.
2. Import into your slicer (Cura/Prusa/etc.).
3. Recommended settings:
4. Layer Height: 0.2 mm
5. Infill: 20%
6. Material: PLA
7. Print both top and bottom parts.
8. Clean the prints and test-fit the components inside.

Your custom enclosure is ready!

Step 2: Making the Circuit 🔌

Connect all components as follows:

Pulse Sensor

1. Signal → A0
2. VCC → 5V
3. GND → GND

OLED Display (SSD1306)

1. SDA → A4
2. SCL → A5
3. VCC → 5V
4. GND → GND

Assembly Steps

1. Place the Arduino Nano on a breadboard.
2. Connect the Pulse Sensor to A0.
3. Connect the OLED via I2C to A4 and A5.
4. Power everything using 5V USB or a battery.
5. Keep wires neat so they fit inside the case.

Step 3: Coding / Programming the Device 💻