neXn.SteamController2026.SDL3 1.0.1

neXn.SteamController2026.SDL3

A lightweight .NET library for detecting the 2026 Steam Controller and reading its battery percentage and power state through SDL3.

Supports USB, Bluetooth, Proteus wireless puck, and Nereid wireless puck connections.

Features

• Detects the Steam Controller 2026
• Reads the current battery percentage
• Reads the current power state
  • OnBattery
  • Charging
  • Charged
  • Unknown
  • Disconnected
• Automatic controller discovery through SDL3
• Handles controller disconnects and reconnects
• Supports the known 2026 Steam Controller connection variants:
  • USB
  • Bluetooth
  • Proteus wireless puck
  • Nereid wireless puck
• Handles the controller's delayed initial battery report
• Thread-safe status queries
• Supports CancellationToken
• Implements both IDisposable and IAsyncDisposable
• Optional Microsoft.Extensions.Logging integration
• Small API surface with SDL-specific implementation details hidden from consumers

Usage

using neXn.SteamController2026.SDL3;

await using SteamControllerClient controller = new();

if (!controller.Initialize())
{
    Console.WriteLine("SDL3 could not be initialized.");
    return;
}

SteamControllerStatus status = await controller.GetStatusAsync();

if (!status.IsConnected)
{
    Console.WriteLine("Steam Controller is disconnected.");
    return;
}

Console.WriteLine($"Battery: {status.BatteryPercentage}%");
Console.WriteLine($"Power state: {status.PowerState}");

Example outputs:

Battery: 82%
Power state: OnBattery

Battery: 64%
Power state: Charging

Initialization

SDL's gamepad subsystem must be initialized before requesting controller data:

SteamControllerClient controller = new();

bool initialized = controller.Initialize();

Initialize() should be called from the application's main thread.

After initialization, GetStatusAsync() can be used for asynchronous battery polling.

Calling GetStatusAsync() before Initialize() results in an InvalidOperationException.

Battery reporting

The 2026 Steam Controller does not necessarily report its battery state immediately after being connected.

SDL may initially report:

PowerState: Unknown
BatteryPercentage: -1

The controller eventually sends its battery telemetry and SDL caches the result.

SteamControllerClient handles this automatically by retrying the battery query for a limited period.

Retries = 50;
DelayBeforeRetry = 250;

These values can be changed:

SteamControllerClient controller = new()
{
    Retries = 60,
    DelayBeforeRetry = 300
};

Once SDL has received a valid battery report, subsequent calls normally return immediately.

Supported connections

The library recognizes the known 2026 Steam Controller device IDs:

SDL3

This library uses SDL3 for controller discovery and battery-state reporting.

SDL handles the device-specific HID communication and exposes the battery information through its gamepad API.

Conceptually:

Steam Controller 2026
        │
        ▼
USB / Bluetooth / Wireless Puck
        │
        ▼
SDL3
        │
        ▼
SDL3-CS
        │
        ▼
neXn.SteamController2026.SDL3
        │
        ▼
Your .NET application

License

This project is licensed under the MIT License.

Disclaimer

This is an independent open-source project and is not affiliated with, endorsed by, or sponsored by Valve Corporation. Steam and Steam Controller are trademarks of their respective owner.