pydpaux 0.1.0

A python wrapper to access DP/eDP-connected display via aux lines.

pyDpaux

A Python wrapper for accessing DP/eDP-connected displays via AUX lines using SoC vendor-specific APIs.

Overview

pyDpaux provides a high-level Python interface to interact with DisplayPort-connected displays through the AUX protocol. It enables reading EDID data, performing I2C communication, and accessing DPCD (DisplayPort Configuration Data) registers.

Currently, only Intel IGCL (Intel Graphics Control Library) API on Windows is implemented. Support for other platforms and vendors is planned. Contributions are welcome!

License: MIT

System Requirements

• Processor: 12th generation (or later) Intel Core processors
• Operating System: Windows 10 or later
• Python: 3.9 or later
• Permissions: Administrator/elevated privileges required for AUX / I2C Write operations

Key Features

• Display Discovery: Enumerate all connected DP/eDP displays
• Display Search: Find displays by partial name matching
• EDID Access: Read and parse Extended Display Identification Data
• AUX Channel Communication: Direct read/write access to DisplayPort AUX channels
• I2C Bus Access: Read/write data via AUX-OVER-I2C protocol
• DPCD Support: Access DisplayPort Configuration Data registers
• Display Properties: Query display name, serial number, and metadata

Installation

From PyPI

pip install pydpaux

From Source

Clone the repository and install in development mode:

git clone <repository-url>
cd pydpaux
pip install .

Building from Source

Prerequisites

• Python 3.9+ with development headers
• Microsoft Visual C++ Build Tools or Visual Studio 2015 or later (for C++ compilation)
• CMake 3.15 or later
• Git

Build Instructions

1. Clone the repository:

   git clone <repository-url>
   cd pydpaux
   

2. Install build dependencies:

   pip install build scikit-build-core pybind11
   

3. Build the extension:

   python -m build
   

   Or for development/editable installation:

   pip install -e .
   

4. Verify installation:

   python -c "import pydpaux; print(pydpaux.__version__)"
   

Quick Start

Basic Usage

Here's a simple example to discover and interact with displays:

import pydpaux

# Get all connected displays
displays = pydpaux.get_displays()

if displays:
    display = displays[0]
    print(f"Found display: {display.name}")
    print(f"Serial: {display.serial}")
    print(f"EDID Size: {display.edid_size} bytes")
else:
    print("No displays found")

Finding a Specific Display

import pydpaux

# Find a display by partial name match
display = pydpaux.find_display_by_name("HDMI")

if display:
    print(f"Found: {display.name}")
else:
    print("No matching display found")

Reading EDID Data

import pydpaux

display = pydpaux.get_displays()[0]

# Read EDID via I2C (first 8 bytes)
edid_header = display.i2c_read(0xa0, 0x00, 8)
print("EDID Header:", ", ".join(f"0x{b:02x}" for b in edid_header))

# Access complete EDID
full_edid = display.edid
print(f"Full EDID size: {len(full_edid)} bytes")

Reading DPCD Registers

import pydpaux

display = pydpaux.get_displays()[0]

# Read individual DPCD registers
print("Reading DPCD registers:")
for addr in [0x00, 0x01, 0x02, 0x03, 0x0C, 0x22, 0x101]:
    value = display.aux_read(addr, 1)[0]
    print(f"  0x{addr:04x}: 0x{value:02x}")

Writing to I2C Bus

import pydpaux

display = pydpaux.get_displays()[0]

# Write data to I2C device at address 0x6e, offset 0x51
data = bytes([0x82, 0x01, 0x10, 0xAC])
try:
    result = display.i2c_write(0x6e, 0x51, data)
    if result == 0:
        print("Write successful")
    else:
        print(f"Write failed with code: 0x{result:08x}")
except PermissionError:
    print("Error: Insufficient permissions. Please run with elevated privileges.")
except RuntimeError as e:
    print(f"Error: {e}")

Complete Example Script

For a comprehensive example, see test/test.py:

import pydpaux
import sys

# Find display by name (if provided as argument) or use first available
name = sys.argv[1] if len(sys.argv) > 1 else ""

if name:
    display = pydpaux.find_display_by_name(name)
    if not display:
        print(f"No display named {name}")
        exit()
else:
    displays = pydpaux.get_displays()
    if not displays:
        print("No display found")
        exit()
    display = displays[0]

print(f"Found display: {display.name}")

# Read EDID via I2C
print("\nTest EDID read with i2c_read():")
edid_data = display.i2c_read(0xa0, 0x00, 8)
print(", ".join(map(lambda x: f'0x{x:02x}', edid_data)))

# Read DPCD registers
print("\nTest DPCD read with aux_read():")
for addr in [0x00, 0x01, 0x02, 0x03, 0x0C, 0x22, 0x101]:
    value = display.aux_read(addr, 1)[0]
    print(f"0x{addr:04x}: 0x{value:02x}")

API Reference

Module Functions

get_displays() -> List[Display]

Get all connected DP/eDP displays.

Returns: List of Display objects

find_display_by_name(keyword: str) -> Display | None

Find a display by partial name match (case-sensitive).

Parameters:

• keyword - Search keyword to match in display names

Returns: First matching Display object or None

Display Class

Properties

• name: str - Display name/identifier
• serial: str - Display serial number
• edid_size: int - Size of EDID data in bytes
• edid: bytes - Complete EDID data

Methods

• aux_read(address: int, size: int) -> bytes - Read from AUX channel
• aux_write(address: int, data: bytes) -> int - Write to AUX channel
• i2c_read(address: int, offset: int, size: int) -> bytes - Read from I2C bus
• i2c_write(address: int, offset: int, data: bytes) -> int - Write to I2C bus
• refresh_handle() -> int - Refresh display output handle

All methods may raise:

• PermissionError - If insufficient privileges (requires administrator mode)
• RuntimeError - If the operation fails

Troubleshooting

"PermissionError: Insufficient permission"

This error indicates that administrator/elevated privileges are required. Run your Python script or terminal with administrator privileges:

• Command Prompt: Right-click and select "Run as administrator"
• PowerShell: Right-click and select "Run as administrator"
• Or use pypy in administrator mode

"No display found"

• Verify that your display is connected via DisplayPort or eDP
• Check that your system has a 12th-gen or later Intel Core processor
• Some systems may have DisplayPort functionality disabled in BIOS

AUX/I2C operations failing with RuntimeError

• Ensure you have a supported Intel GPU with IGCL API support
• Verify display connection is stable
• Try calling refresh_handle() to update the display handle

Contributing

Contributions are welcome! Areas for improvement include:

• Support for other platforms (Linux, macOS)
• Support for other GPU vendors (AMD, NVIDIA)
• Additional display control functionality
• Bug reports and fixes

Supported Platforms

Platform	Status	GPU Support
Windows 10+	✅ Supported	Intel IGCL API (12th gen+)
Linux	📋 Planned	-
macOS	📋 Planned	-

Resources

• DisplayPort Standard
• EDID Format
• I2C Protocol
• Intel IGCL API Documentation

License

This project is licensed under the MIT License. See LICENSE file for details.

Citation

If you use pyDpaux in your research or project, please cite it as:

pyDpaux - Python DisplayPort AUX Access Wrapper
https://github.com/<username>/pydpaux

Support

For issues, questions, or suggestions:

• 📝 Create an Issue
• 💬 Discussions

Disclaimer

This software provides direct access to display hardware interfaces. Improper use may affect display functionality. Use at your own risk and always test in a controlled environment.