Project 001

Smart Heart Rate Monitor 💓

A comprehensive Arduino-based heart rate monitoring system featuring real-time BPM detection, customizable alarms, and an intuitive OLED interface.

✨ Features

• 📊 Real-time Heart Rate Monitoring - Continuous BPM detection with rolling average
• 🖥️ OLED Display Interface - Clear, intuitive menu system
• 🚨 Smart Alarm System - Customizable high/low BPM thresholds
• 📈 Session Statistics - Track min/max BPM and session duration
• 💡 Visual Indicators - LED status feedback and heartbeat animation
• ⚙️ User-Friendly Controls - Three-button navigation system
• 🔧 Sensor Calibration - Built-in sensor status monitoring

🛠️ Hardware Requirements

Components

• Arduino Nano v3.x - Main microcontroller
• MAX30102 - Heart rate and pulse oximetry sensor
• SSD1306 OLED Display (128x64) - User interface
• 3x Push Buttons (SW1, SW2, SW3) - User input
• 1x LED (D1) - Status indicator
• 3x Pull-up Resistors (1kΩ) - Button debouncing
• 3x Capacitors (100nF) - Power filtering

Pin Connections

📚 Software Requirements

Arduino Libraries

Install these libraries through the Arduino Library Manager:

Adafruit SSD1306        // OLED display driver
Adafruit GFX Library    // Graphics library
MAX30105lib             // SparkFun MAX3010x sensor library

Library Installation

1. Open Arduino IDE
2. Go to Sketch → Include Library → Manage Libraries
3. Search and install each library listed above
4. Restart Arduino IDE

🚀 Installation & Setup

1. Hardware Assembly

• Follow the pin connection table above
• Ensure proper power connections (3.3V or 5V)
• Connect I2C devices to the same bus (SDA/SCL)
• Add pull-up resistors to button connections

2. Software Upload

# Clone the repository
git clone https://github.com/Aleksanry/Smart_Heart_Rate_Monitor.git

# Open the Arduino file
# HR_Monitor_Firmware/HR_Monitor_Firmware.ino

# Select your board: Arduino Nano
# Select the correct COM port
# Click Upload

3. Sensor Calibration

1. Power on the device
2. Navigate to Settings Menu → Sensor Config
3. Ensure IR signal shows values > 10000 when finger is placed
4. If values are low, check sensor connections

🎮 User Interface Guide

Button Controls

• SW1 (Menu) - Navigate between screens, confirm selections
• SW2 (Up) - Navigate up, increase values
• SW3 (Down) - Navigate down, decrease values

Screen Navigation

Main Screen
    ↓ (SW1)
Settings Menu
    ↓ (SW1)
┌─ Alarm Settings
└─ Sensor Calibration

Main Display Elements

• Large BPM Reading - Current heart rate
• Status Indicator - LOW/NORMAL/HIGH
• Alarm Status - ON/OFF indication
• Session Timer - Minutes and seconds elapsed
• Heartbeat Animation - Visual pulse indicator
• Alarm Banner - Flashing when triggered

⚙️ Configuration Options

Alarm Settings

• Minimum BPM: Default 60, Range 30-120
• Maximum BPM: Default 100, Range 80-220
• Alarm Enable/Disable: Toggle alarm functionality

Sensor Parameters

• LED Brightness: 60 (adjustable in code)
• Sample Rate: 400 Hz
• Sample Average: 4 readings
• Pulse Width: 411 µs

🔍 Troubleshooting

Common Issues

No Heart Rate Reading

• Check sensor placement (fingertip on sensor)
• Verify MAX30102 connections
• Ensure adequate lighting conditions
• Check I2C address (default 0x57)

Display Not Working

• Verify OLED connections (SDA/SCL)
• Check I2C address (default 0x3C)
• Ensure adequate power supply

Buttons Not Responding

• Check analog pin connections
• Verify pull-up resistors are installed
• Test button continuity

Inaccurate Readings

• Keep finger steady during measurement
• Avoid excessive pressure on sensor
• Wait for stabilization (10-15 seconds)

Debug Mode

Enable serial monitoring at 115200 baud for diagnostic information:

Serial.begin(115200);  // Already included in code

📊 Technical Specifications

Performance

• Update Rate: 20ms sensor reading, 500ms display refresh
• Accuracy: ±2 BPM (typical)
• Range: 20-220 BPM
• Response Time: 3-5 seconds for stable reading

Power Consumption

• Active Mode: ~50mA @ 5V
• Display On: ~30mA additional
• Sensor Active: ~15mA additional

Memory Usage

• Program Memory: ~75% of Arduino Nano
• Dynamic Memory: ~60% of available RAM

🔧 Customization

Modifying Thresholds

// Default alarm thresholds (in setup())
int minHeartRate = 60;    // Lower limit
int maxHeartRate = 100;   // Upper limit

Display Update Rate

// Update intervals (in milliseconds)
const unsigned long DISPLAY_UPDATE_INTERVAL = 500;  // 500ms
const unsigned long SENSOR_READ_INTERVAL = 20;      // 20ms

LED Behavior

// Alarm LED patterns
digitalWrite(LED_PIN, (millis() / 250) % 2);  // Fast blink (250ms)
digitalWrite(LED_PIN, (millis() / 1000) % 2); // Slow blink (1000ms)

Code Style Guidelines

• Use descriptive variable names
• Comment complex algorithms
• Follow Arduino naming conventions
• Test on actual hardware before submitting

🙏 Acknowledgments

• SparkFun for the excellent MAX30105 library
• Adafruit for the comprehensive display libraries
• Arduino Community for continuous support and inspiration

🔮 Future Enhancements

• Bluetooth connectivity for data logging
• SD card storage for long-term monitoring
• Mobile app integration
• Multiple user profiles
• Advanced analytics and trends
• Voice alerts
• Battery level monitoring

⚠️ Medical Disclaimer: This device is for educational and recreational purposes only. It is not intended for medical diagnosis or treatment. Always consult healthcare professionals for medical advice.

Made with ❤️ by Nermin | Arduino Heart Rate Monitor v1.0