steamdeck-hid 0.2.3

A Python library for handling Steam Deck inputs

steamdeck-hid

A reusable Python library for handling Steam Deck controller inputs using evdev and hid. This library allows you to monitor button presses, analog stick movements, touch pads, and other inputs from the Steam Deck in a non-blocking, asynchronous manner. It supports event subscription via callbacks, making it suitable for integration into games, automation scripts, or custom applications on SteamOS or other Linux environments.

The library is designed for Linux systems (tested on Steam Deck with SteamOS) and requires root privileges or appropriate permissions to access input devices (e.g., via sudo or adding your user to the input group).

Features

• Asynchronous event reading from multiple input devices.
• Support for buttons (A/B/X/Y, D-Pad, triggers, bumpers, etc.), analog sticks, touch pads, and power/volume buttons.
• Customizable device paths for flexibility across different setups.
• Adjustable polling interval to control responsiveness and CPU usage.
• Event subscription model: Register callbacks to react to input changes.
• Helper functions to list available devices and decode HID reports.
• Lightweight with minimal dependencies.

Installation

Install the library via pip (works on Linux, macOS, and other platforms, but full functionality is Linux-only):

pip install steamdeck-hid

• On Linux/Steam Deck: Automatically includes all dependencies for full support.
• On non-Linux systems (e.g., macOS, Windows): Installation succeeds, but usage of core features (e.g., SteamDeckInput) will raise an error indicating lack of support.

Dependencies

• hid: For raw HID report reading (cross-platform, always installed).
• evdev: For reading input events from /dev/input/event* devices (automatically installed on Linux only).

Note: This library is Linux-specific due to its reliance on evdev and HID raw devices. On non-Linux systems, you can still use standalone functions like decode_steamdeck_report (if they don't require evdev), but device reading features are unavailable.

If you encounter permission issues on Linux (e.g., "Permission denied" when accessing devices), run your script with sudo or add your user to the input group:

sudo usermod -aG input $USER

Log out and back in for changes to take effect.

Quick Start

Here's a basic example to get started. This script lists devices, initializes the input handler, subscribes to events, and prints changes:

import asyncio
from steamdeck_hid import SteamDeckInput, list_all_devices

async def main():
    # Optional: List all available input devices to verify paths
    list_all_devices()

    # Initialize with default paths (customize if needed)
    sdi = SteamDeckInput(
        device_paths=['/dev/input/event5', '/dev/input/event2', '/dev/input/event8', '/dev/input/event14'],
        hidraw_path='/dev/hidraw2',
        polling_interval=0.001  # Default: 1ms; adjust for CPU/responsiveness trade-off
    )

    # Define a callback for input changes
    def my_callback(key, value):
        print(f"Input event: '{key}' changed to {value}")

    # Subscribe the callback
    sdi.add_listener(my_callback)

    # Start listening (runs indefinitely until interrupted)
    print("Listening for Steam Deck inputs... Press Ctrl+C to stop.")
    await sdi.start()

if __name__ == "__main__":
    try:
        asyncio.run(main())
    except KeyboardInterrupt:
        print("Program terminated by user")
    except Exception as e:
        print(f"Error: {e}")

Run this script with:

python your_script.py

Or with sudo if needed:

sudo python your_script.py

Expected Output

When you press buttons or move sticks/pads, you'll see output like:

Input event: 'A' changed to True
Input event: 'LEFT_STICK_X' changed to 1234
Input event: 'VOLUME_UP' changed to True

Advanced Usage

Customizing Device Paths

If your Steam Deck's device paths differ (e.g., due to kernel updates or hardware variations), use list_all_devices() to identify them and pass custom paths:

sdi = SteamDeckInput(
    device_paths=['/dev/input/eventX', '/dev/input/eventY'],  # Replace with your paths
    hidraw_path='/dev/hidrawZ'
)

The power/volume buttons are typically on one specific device (default: /dev/input/event5). The library handles this internally.

Adjusting Polling Interval

To balance responsiveness and CPU usage, set the polling_interval (in seconds) during initialization. Lower values (e.g., 0.001 for 1ms) provide faster updates but may increase CPU load; higher values (e.g., 0.01 for 10ms) reduce CPU usage at the cost of slight delay.

sdi = SteamDeckInput(polling_interval=0.01)  # 10ms interval

Default is 0.001 (1ms).

Multiple Callbacks

You can add multiple listeners:

def callback1(key, value):
    if key == 'POWER':
        print("Power button pressed!")

def callback2(key, value):
    print(f"Generic event: {key} = {value}")

sdi.add_listener(callback1)
sdi.add_listener(callback2)

Supported Inputs

The library tracks the following keys in the state dictionary (booleans for buttons, integers for axes):

• Buttons: A, B, X, Y, UP, DOWN, LEFT, RIGHT, L1, R1, L2, R2, L4, L5, R4, R5, STEAM, MENU, WINDOW, MORE, POWER, VOLUME_UP, VOLUME_DOWN
• Presses/Touches: LEFT_PAD_PRESS, RIGHT_PAD_PRESS, LEFT_PAD_TOUCH, RIGHT_PAD_TOUCH, LEFT_STICK_PRESS, RIGHT_STICK_PRESS, LEFT_STICK_TOUCH, RIGHT_STICK_TOUCH
• Axes: LEFT_STICK_X, LEFT_STICK_Y, RIGHT_STICK_X, RIGHT_STICK_Y, LEFT_PAD_X, LEFT_PAD_Y, RIGHT_PAD_X, RIGHT_PAD_Y

Changes are only triggered for significant movements (e.g., >200 for sticks, >100 for pads) to reduce noise.

Decoding HID Reports Manually

If you need low-level access, use the standalone decode_steamdeck_report function:

from steamdeck_hid import decode_steamdeck_report

buttons_state = {}
data = b'your_raw_hid_data_here'  # Example: read from hid device
decode_steamdeck_report(data, buttons_state)
print(buttons_state)  # {'A': True, 'LEFT_STICK_X': 0, ...}

Error Handling and Cleanup

The library automatically grabs and ungrabs devices. On exit (e.g., Ctrl+C), it releases resources. Handle exceptions in your main function for robustness.

Contributing

Contributions are welcome! Fork the repository on GitHub, make changes, and submit a pull request. Please include tests and update documentation.

License

MIT License

Copyright (c) 2025 Oleh Polishchuk

See the LICENSE file for details.

Troubleshooting

• Device not found: Use list_all_devices() to confirm paths. Update paths accordingly.
• Permission denied: Run with sudo or adjust group permissions.
• No events: Ensure the Steam Deck is connected and not in desktop mode with inputs routed elsewhere.
• High CPU usage: Increase the polling_interval (e.g., to 0.01 for 10ms) to reduce polling frequency.

For issues, open a ticket on the GitHub repository (replace with your actual repo URL).