OLED Aegis

A Windows screen saver app tailored for OLED monitors.

Why I made this

Recently, I purchased my first OLED monitor and discovered that Windows 11 built-in screen saver has some issues:

• Randomly not activating after putting the computer to sleep.
• Breaks Bluetooth pause/play interactions when the screen saver is active.
• Does not provide a way to only turn on screen saver on one monitor in a multi-monitor setup. (I only want to enable the screen saver on my OLED monitor)

Solution: make my own screen saver app and give it a bad name.

OLED Aegis solves these problems by implementing a screen saver app in the simplest way possible: draw a black fullscreen window after a period of user inactivity on the specified monitors.

Note: It should work just fine on Windows 10, but I only tested it on Windows 11.

Download & Installation

Download the latest oled_aegis.exe from the Releases page. No installation required - simply run the executable.

For convenient access, you can place it in any folder and create a shortcut, or add it to your Windows startup folder.

Features

• Per-Monitor Control: Enable screen saver on specific monitors only
• Per-Monitor Input Detection: Optionally track input separately for each monitor, allowing unused monitors to activate screen saver while you continue using others
• Media Awareness: Doesn't activate the screen saver if a video is playing
• Reliable Activation: Consistently activates after system sleep/wake cycles
• Minimal Resource Usage: Written in pure C with no external dependencies
• Simple Configuration: Edit a plain text INI file or use the system tray menu
• System Tray Integration: Taskbar icon for easy control
• Startup Support: Automatically run when Windows starts

Configuration

Configuration is stored in %APPDATA%\OLED_Aegis\oled_aegis.ini. This file is created automatically on first run.

Settings

• idleTimeout: Seconds of inactivity before screen saver activates (default: 300 seconds = 5 minutes)
• checkInterval: Milliseconds between idle time checks (default: 1000ms, min: 250ms, max: 10000ms)
• pixelShiftCompensation: Pixels to expand the screen saver window beyond the monitor's reported bounds on each side (default: 0, disabled). Set to 4–8 if your QD-OLED panel's hardware pixel shift feature causes a thin strip of the desktop to appear at the screen edge during screen saver activation.
• mediaDetectionEnabled: Set to 1 to prevent screen saver during media playback, 0 to disable (default: 1)
• startupEnabled: Set to 1 to run at Windows startup, 0 to disable (default: 0)
• debugMode: Set to 1 to enable debug logging to %APPDATA%\OLED_Aegis\oled_aegis_debug.log, 0 to disable (default: 0). Note: only for troubleshooting issues.
• perMonitorInputDetection: Set to 1 to track input separately for each monitor (default: 0). When enabled, each monitor has its own idle timer based on mouse cursor position and focused window location. This allows the screen saver to activate on unused monitors while you continue working on others.
• monitorEnabled_<device>: Set to 1 to enable screen saver on the specified monitor, 0 to disable (default: 1 for all).

Usage

System Tray

• Right-click the tray icon to access:

  • Settings (shows config file location)
  • Enable/Disable Startup
  • Exit

• Left-click to toggle screen saver manually

Behavior

Global Mode (default)

The screen saver will automatically activate on all enabled monitors when:

1. No user input (keyboard/mouse) for idleTimeout seconds
2. No media is playing (if mediaDetectionEnabled=1)

The screen saver will automatically deactivate from all monitors when:

1. Any user input is detected
2. Media starts playing (if mediaDetectionEnabled=1)

Per-Monitor Mode (perMonitorInputDetection=1)

Each enabled monitor has its own independent idle timer. Input is attributed to monitors based on:

• Mouse movement: Updates the idle timer for the monitor where the cursor is located
• Keyboard input: Updates the idle timer for the monitor containing the focused window, and also the monitor where the cursor is located

This allows you to:

• Continue using one monitor while others activate their screen savers
• Have different monitors timeout independently based on where you're actively working
• Keep your OLED monitor protected while watching content on a secondary display

Building

Requires Visual Studio (2015 or later) with the C++ build tools installed.

Windows (Command Prompt)

build.bat

Windows (PowerShell)

.\build.ps1

WSL

./build.sh

Manual Build

cl.exe src\oled_aegis.c /Fe:oled_aegis.exe /O2 /MD /link user32.lib shell32.lib ole32.lib uuid.lib gdi32.lib advapi32.lib comctl32.lib powrprof.lib psapi.lib

See BUILD.md for more information.

Why didn't you just make a custom Screen Saver (.scr)?

From my testing, it is not possible to have a real Windows screensaver (.scr launched by the OS) affect only one monitor while leaving the others showing their normal desktop / video playback.

Even if a .scr program specifically draws on only one monitor, when Windows activates a screensaver due to timeout, Explorer switches into a screensaver mode and the desktop window manager creates an internal blank backdrop surface which is applied to all monitors.

Also, one of the primary issues I had with the built-in screen saver was it's apparent disabling of Bluetooth media controls, so using the built-in screen saver wouldn't resolve this particular issue.