libhr 🫀

libhr is a modern, cross-platform C++ library for interacting with Bluetooth Low Energy (BLE) Heart Rate Monitors. It provides a simple, robust interface to discover devices, stream data, and perform advanced cardiovascular analysis (HRV, Recovery, Zones, etc.).

Features

• BLE Device Management: Connect, read, and manage BLE heart rate monitors effortlessly.
• Advanced Metrics & Analysis:
  • Heart Rate Variability (HRV) calculation
  • Rolling Averages & Signal Smoothing
  • Workout Zones (e.g., Fat Burn, Aerobic, Anaerobic)
  • Trend Detection (Increasing/Decreasing)
  • Peak Detection & Recovery Rate Calculation
  • Comprehensive Session Statistics (Min, Max, Avg, etc.)
• Versatile Utilities:
  • Export data to CSV/JSON formats for external analysis.
  • Playback mode for recorded sessions (ideal for testing/development).
  • Battery level monitoring for BLE devices.

Supported Platforms

Currently focusing on Apple-based systems (macOS, iOS) via CoreBluetooth.

Planned future support for:

• Windows (via WinRT)
• Linux (via BlueZ)
• Android

Installation & Build

Build libhr and the accompanying heart-cli tool using CMake.

mkdir build && cd build
cmake ..
cmake --build .

CLI Tool (heart-cli)

A command-line tool heart-cli is included for rapid testing and debugging.

# Scan and connect to the nearest Heart Rate Monitor
./heart-cli --monitor

# Export real-time data to a CSV
./heart-cli --monitor --export session.csv

Roadmap

• Core BLE connection and data reading functionality.
• Implement robust unit testing to ensure reliability and correctness.
• Flesh out advanced metrics functions (HRV, Zones, Trending).
• Implement backend support for Windows, Linux, and Android.
• Create an iOS/macOS demonstration application.
• CI/CD pipeline for automated testing and deployment.