Discover and locally control Yeelight WiFi LEDs over your LAN, from Rust. No cloud, no account — just the device's documented LAN control protocol.

The workspace contains the yeelight-core library plus a yeelight-gui desktop app (iced) and a yeelight-mock harness for hardware-free development.

• Discovery — active search() and a passive Listener over the Yeelight SSDP-like multicast protocol.
• Typed control — a Client per device with one method per protocol command (power, RGB/HSV/CT, brightness, color flow, scenes, cron, adjust), each validating its arguments before they hit the wire. Background-light (bg_*) twins included.
• Async notifications — subscribe to the device's pushed state-change stream.
• Music mode — MusicConnection for unthrottled, fire-and-forget streaming (the device connects back to you).
• Registry — persist discovered devices to TOML so later runs can skip a fresh search.
• Firewall helpers — open the static UDP/TCP ports via ufw on Linux.

Add the crate to your workspace (it is not yet published to crates.io):

[dependencies]
yeelight-core = { path = "crates/yeelight-core" }
tokio = { version = "1", features = ["full"] }

Discover a device and set it red:

use std::time::Duration;
use yeelight_core::{discovery, firewall, Client, Effect};

#[tokio::main]
async fn main() -> yeelight_core::Result<()> {
    firewall::ensure_udp_open(discovery::SSDP_PORT).await?;
    let devices = discovery::search(Duration::from_secs(3)).await?;
    if let Some(device) = devices.into_iter().next() {
        let client = Client::connect(device).await?;
        client.set_power(true, Effect::Smooth(500), None).await?;
        client.set_rgb(0xFF0000, Effect::Smooth(500)).await?;
    }
    Ok(())
}

Note: "LAN Control" must be enabled for each bulb in the Yeelight app, otherwise the control port stays closed.

Runnable examples live in crates/yeelight-core/examples/ and require a real bulb on your network:

cargo run -p yeelight-core --example discover   # find devices and print them
cargo run -p yeelight-core --example control    # connect and drive one device
cargo run -p yeelight-core --example music      # stream commands over music mode

cargo run -p yeelight-gui   # discover and control bulbs from a window

The GUI's Ambient section mirrors a screen region's color onto the bulb in real time. Pick a region (whole / top / bottom / left / right), an extraction mode (average / dominant / average+saturation), and which light(s) to drive; it streams over music mode at ~15 fps when available, otherwise falls back to rate-limited set_rgb at ~2 fps. Targets that only support color temperature (white-only bulbs) are driven by a warm/cool K mapping instead of full RGB.

• Linux (Wayland): captures via the grim CLI (wlr-screencopy), so install grim. Monitor enumeration uses hyprctl (Hyprland); other wlroots compositors capture fine but the multi-monitor picker won't list displays. No PipeWire/portal and no screen-share dialog.
• macOS / Windows: capture via scap-rs (ScreenCaptureKit / DXGI); build needs libclang (clang). macOS prompts for Screen Recording permission on first use; Windows shows no prompt (a capture border may appear).

cargo test                  # unit tests — no device or network needed
cargo clippy --all-targets  # lints
cargo doc --open            # full API docs

MIT