PyBookLid - MacBook Lid Angle Sensor

A Python library for reading MacBook lid angle sensor data on macOS. This library provides real-time access to the built-in lid angle sensor available on modern MacBooks.

Features

• One-shot readings - Get the current lid angle instantly
• Continuous monitoring - Stream angle changes in real-time
• Adaptive audio synthesis - Generate door creak sounds that respond to movement
• Context manager support - Clean resource management
• Type hints - Full typing support for better IDE integration
• Error handling - Graceful handling of sensor unavailability

Requirements

• macOS (tested on Apple Silicon)
• Python 3.7+
• Modern MacBook with lid angle sensor (most 2019+ models)

Installation

Install from PyPI:

pip install pybooklid

Or install with audio features for creak sound generation:

pip install pybooklid[audio]

The library automatically handles the required DYLD_LIBRARY_PATH setup for hidapi on macOS.

Development Installation

1. Clone this repository:

git clone <repository-url>
cd pybooklid

2. Install in development mode:

pip install -e .
# Or with audio features
pip install -e .[audio]

Quick Start

One-shot reading

from pybooklid import read_lid_angle

angle = read_lid_angle()
if angle is not None:
    print(f"Current lid angle: {angle:.1f}°")
else:
    print("Sensor not available")

Continuous monitoring

from pybooklid import LidSensor

with LidSensor() as sensor:
    for angle in sensor.monitor(interval=0.1):
        print(f"Angle: {angle:.1f}°")
        if angle < 10:  # Nearly closed
            break

Advanced usage

from pybooklid import LidSensor

# Manual connection management
sensor = LidSensor(auto_connect=False)
try:
    sensor.connect()
    
    # Wait for significant movement
    new_angle = sensor.wait_for_change(threshold=5.0, timeout=10.0)
    if new_angle:
        print(f"Lid moved to {new_angle:.1f}°")
    
    # Monitor with callback
    def on_angle_change(angle):
        print(f"Callback: {angle:.1f}°")
    
    for angle in sensor.monitor(callback=on_angle_change, max_duration=30):
        # Process angle data
        pass
        
finally:
    sensor.disconnect()

API Reference

LidSensor Class

The main sensor interface class.

Methods:

• __init__(auto_connect=True) - Initialize sensor, optionally auto-connecting
• connect() - Connect to the lid angle sensor
• disconnect() - Disconnect from the sensor
• is_connected() - Check connection status
• read_angle() - Get current angle in degrees (0-180°)
• monitor(interval=0.1, callback=None, max_duration=None) - Continuous monitoring iterator
• wait_for_change(threshold=1.0, timeout=None) - Wait for angle to change

Convenience Functions

• read_lid_angle() - Quick one-shot reading
• is_sensor_available() - Check if sensor is available

Command Line Tools

After installation, you can use the command line tools:

# Run basic sensor demo
pybooklid-demo

# Run advanced monitoring app
pybooklid-monitor

Sensor Details

The lid angle sensor reports values in degrees:

• 0° - Lid fully closed
• 90° - Lid at right angle
• ~180° - Lid fully open (varies by MacBook model)

The sensor uses Apple's HID interface:

• Vendor ID: 0x05AC (Apple)
• Product ID: 0x8104 (Sensor Hub)
• Usage Page: 0x0020 (Sensor)
• Usage: 0x008A (Orientation)

Error Handling

The library includes comprehensive error handling:

• LidSensorError - Base exception for sensor-related errors
• Graceful degradation when sensor is unavailable
• Automatic reconnection attempts
• Safe cleanup on exit

Compatibility

Tested on:

• MacBook Pro (Apple Silicon)
• macOS Sonoma/Sequoia
• Python 3.12

Should work on most modern MacBooks with lid angle sensors.

Example Scripts

Simple Usage (examples/simple_usage.py)

Demonstrates basic sensor usage patterns and gesture detection.

Advanced Monitor (examples/monitor_app.py)

Full-featured monitoring application with statistics, logging, and CSV export.

Troubleshooting

"Sensor not found" error

• Ensure you're on a supported MacBook model
• Try running with sudo if permission issues occur
• Check that no other applications are using the sensor

Library import errors

• Verify hidapi installation: pip show hidapi
• On older macOS, install Homebrew and run brew install hidapi

Inconsistent readings

• The sensor may have noise - use averaging for stable readings
• Some MacBook models may have different angle ranges

Development

Based on reverse engineering of the IOKit HID interface used by Apple's internal sensor framework.

Credits

This library was made possible by the reverse engineering work done by Sam Henri Gold in the LidAngleSensor project. The key insights about the HID Feature Reports and data format were discovered through that original research.

Key insights:

• Uses HID Feature Reports (not Input Reports)
• Report ID 1 contains angle data
• Data format: [report_id, angle_low_byte, angle_high_byte]
• 16-bit little-endian angle value in degrees

License

MIT License - see LICENSE file for details.

Contributing

Contributions welcome! Please test on different MacBook models and report compatibility.