LGforWin

A small native WinUI 3 Windows app to control the brightness (OLED Light) of LG webOS TVs used as PC monitors — C2, C3, G-series and friends — over your LAN.

OLED TVs have no DDC/CI hardware brightness, so the Windows brightness slider does nothing. The only real "brightness" control is the TV's OLED Light (backlight) picture setting. LGforWin drives that setting over the network so you can change it from your desk — with a slider, the system tray, or global hotkeys.

Download

⬇ Download LGforWin v2.1.0

LGforWin-2.1.0-setup.exe	Installer — Start-menu shortcut and an uninstall entry.
LGforWin-2.1.0-win-x64.zip	Portable — unzip and run LGforWin.exe.

64-bit Windows 10 1809 or newer. Nothing else to install — the .NET runtime and the Windows App SDK are bundled. The build isn't code-signed yet, so SmartScreen shows an "unrecognized app" warning on first run: choose More info → Run anyway.

Features

• Find TVs automatically — one click scans the LAN over SSDP and adds any webOS TV it finds, so you never have to hunt for an IP address. Adding by IP still works.
• Power automation — turn the TVs on and off with the PC: at startup, on sleep, on shutdown, and following Windows' display-sleep timer (blank the panel for an instant resume, or power off fully). Waking uses Wake-on-LAN.
• Add TVs by IP; pair once (accept the on-screen prompt), then it reconnects silently forever using the stored client-key. Secure wss://:3001 with automatic fallback to ws://:3000.
• Per-TV OLED Light slider (0–100) that pushes changes live (debounced).
• Global hotkeys (customizable combo) that adjust the TV on the screen your cursor is on — pair each TV to its Windows monitor so it knows which is which. Ten points per press by default, adjustable 1–25.
• On-screen display — a Windows 11-style brightness overlay on the hotkey, with configurable position, screen, duration and optional TV name.
• Schedules — up to 10 daily brightness rules, with catch-up on startup, after PC sleep, and for TVs that were off when a schedule fired (applied the moment they're back).
• System tray icon — closing hides to tray; optional launch at sign-in (normal window / minimized / tray).
• Import / export all settings; light / dark / system theme.
• Remembers multiple TVs, their last brightness, and the window size.

On-screen display

Nudge brightness with the hotkeys and a Windows 11-style overlay slides in — on the screen of the TV you're adjusting:

Screens

Power — follow the PC's sleep, shutdown and display timer	Schedules — up to 10 daily rules
Hotkeys — cursor-targeted, customizable combo	On-screen display settings
Settings — theme, autostart, import/export

How it works (protocol)

webOS speaks SSAP over a WebSocket at ws://<tv-ip>:3000:

1. Pair — send a registration handshake. The TV shows an accept prompt and returns a client-key, which we persist and reuse so it never prompts again.
2. Set brightness — ssap://com.webos.settingsservice/setSystemSettings with { "category": "picture", "settings": { "backlight": "<0-100>" } }. (Falls back to ssap://settings/setSystemSettings on firmware that rejects the internal URI.)
3. Read current — ssap://settings/getSystemSettings to initialise the slider.
4. Power — ssap://system/turnOff to switch off, and …tvpower/power/turnOffScreen / turnOnScreen to blank and restore just the panel. …tvpower/power/getPowerState reports Active / Screen Off / Suspend, which doubles as a liveness probe: a TV that loses power doesn't close the WebSocket, so without asking it we'd keep reporting "connected" to a set that's long gone.
5. Wake — a TV that's off can't be reached over SSAP at all, so waking is a Wake-on-LAN magic packet to the MAC learned via ARP while it was still reachable. The TV needs Quick Start+ (or "Turn on via Wi-Fi") enabled to answer it.

Works on stock TVs — no rooting required. Prior art: bscpylgtv, ColorControl, lgtv2.

Project layout

Path	Purpose
Services/WebOsClient.cs	Low-level SSAP WebSocket: connect, pair, request/response
Services/TvController.cs	Per-TV lifecycle, auto-reconnect, heartbeat, power, debounced SetBacklight
Services/SsdpDiscovery.cs	LAN scan for webOS TVs (SSDP M-SEARCH + UPnP description)
Services/WakeOnLan.cs	ARP MAC lookup + magic-packet wake
Services/PowerEventService.cs	Windows sleep / resume / display-off / shutdown notifications
Services/SsapPayloads.cs	Registration manifest + SSAP URIs
Services/DeviceStore.cs	JSON persistence in %LOCALAPPDATA%\LGforWin
Services/HotkeyService.cs	Global hotkeys via RegisterHotKey
ViewModels/	MainViewModel, TvViewModel (CommunityToolkit.Mvvm)
Views/MainWindow.xaml	TV list, sliders, add/remove, tray icon
Program.cs / App.xaml.cs	Custom entry point, single-instance, startup wiring

Building

Prerequisites

• .NET 8 SDK (winget install Microsoft.DotNet.SDK.8)
• Visual Studio 2022/2026 with the .NET desktop development workload (provides the WinUI/MSIX MSBuild tasks; the standalone .NET SDK alone is not enough).

Build & run

Open LGforWin.sln in Visual Studio and press F5, or from a terminal:

pwsh -File build.ps1 -Configuration Debug -Run

Package a release — writes the portable zip and setup.exe to dist\:

pwsh -File build.ps1 -Configuration Release -Package

The installer needs Inno Setup 6 (winget install JRSoftware.InnoSetup); without it the zip is still produced.

Note: build with Visual Studio's MSBuild (what build.ps1 does), not dotnet build — WinUI PRI generation needs the AppxPackage task that only ships with VS, so dotnet build fails with MSB4062.

Usage

1. Make sure the TV is on the same network and "LG Connect Apps" / mobile control is enabled (Settings → Network/Connection).
2. Launch LGforWin and click Find TVs — pick yours from the list and hit Add. (Or type a name + IP and click Add TV.)
3. Accept the pairing prompt on the TV (one time).
4. Drag the slider — brightness changes within ~150 ms. Use Ctrl+Alt+Up/Down anytime.
5. Optional: on the Power page, choose what should happen to the TVs when the PC starts, sleeps, shuts down, or Windows blanks the displays.

For the "turn on" rules, enable Quick Start+ on the TV (General → Devices → External Devices, wording varies) — that's what lets it answer Wake-on-LAN. Note that once Windows sleeps a display it stops sending a picture, so the TV will usually power itself off on "no signal" a few minutes later even if you chose "Screen off"; waking covers both cases.

Roadmap

Planned features and ideas are tracked in Todo.md.

License

Licensed under the GNU General Public License v3.0 © Alex Bolocan.