emeet-pixyd
_{Auto-activation daemon for the EMEET PIXY dual-camera AI webcam}

Linux-native daemon that makes your PIXY webcam smart:
face tracking on call start · privacy mode on call end · audio switching · DataStar web UI

Why

The EMEET PIXY is a great dual-camera AI webcam — but on Linux, you're stuck manually enabling face tracking before calls, switching audio sources, and remembering to enable privacy mode when you're done. emeet-pixyd automates all of that.

It watches /proc to detect when a video call starts (Zoom, Teams, Google Meet, anything that opens the camera), then:

Activates face tracking + noise cancellation
Switches your PipeWire audio source to the PIXY microphone
When the call ends, enters privacy mode (lens physically blocked)

No setup per app. No browser extension. Works with anything that opens /dev/video*.

Who is this for?

Linux users with an EMEET PIXY who want face tracking and privacy to "just work" on every call.
Remote workers tired of manually enabling tracking before meetings and remembering privacy mode after.
NixOS users who want a declarative, reproducible setup via a single module option.
Waybar / tiling-WM users who want live camera status (mode, PTZ, in-call) in their bar.
Privacy-conscious users who want a guaranteed physical lens block whenever no call is active.

When NOT to use this

Skip this daemon if:

You don't own an EMEET PIXY (328f:00c0) — this is hardware-specific, not a generic webcam tool. Reach for webcamoid instead.
You're on macOS or Windows — this is Linux-only by design (HID hidraw, V4L2, /proc, netlink uevents).
The camera's own tracking toggle is enough for you — if you never forget to enable it, you don't need a daemon.
You want cloud or AI features — this is fully local, no network calls, no telemetry.
You need multi-vendor webcam management — this targets one device family. See Related Tools for general-purpose alternatives.

Comparison

Approach	Auto call detection	Privacy on end	Audio switching	Hotplug	Linux-native
emeet-pixyd	✓	✓	✓	✓	✓
Manual `v4l2-ctl` per call					✓
Vendor Windows/Mac app	✓		✓
webcamoid					✓

The differentiator is the first column: emeet-pixyd is the only option that detects calls by watching /proc, so it works with any app that opens the camera — no per-app setup, no browser extension.

Features

Feature	Description
Call detection	Scans `/proc/*/fd` for processes holding the video device — works with any app
Auto-activate	Enables face tracking + noise cancellation when a call starts
Auto-privacy	Physically blocks the lens when the call ends
Audio switching	Auto-switches PipeWire default source to PIXY on call start
Web UI	Dark-themed DataStar control panel with live MJPEG preview, PTZ sliders, and toast notifications
Waybar integration	JSON output for a custom Waybar module
Hotplug	Netlink uevent listener detects USB plug/unplug, auto-re-probes
Prometheus metrics	OTel-based metrics at `/metrics` for monitoring
NixOS module	Systemd user service, udev rules, tmpfiles.d — one option to enable

Quick Start

NixOS (recommended)

Add the flake input and enable the module:

# flake.nix
inputs.emeet-pixyd.url = "github:LarsArtmann/emeet-pixyd";

# In your nixosConfiguration:
inputs.emeet-pixyd.nixosModules.default

Then in your configuration:

hardware.emeet-pixy = {
  enable = true;
  auto = "full";           # off | full | tracking-only | privacy-only
  defaultAudio = "nc";     # nc | live | org
  debug = false;
};

That's it. The module installs the daemon, udev rules, systemd user service, and all runtime dependencies.

Build from Source

git clone https://github.com/LarsArtmann/emeet-pixyd.git
cd emeet-pixyd
nix build    # or: go build -o emeet-pixyd .

Usage

Run without arguments to start the daemon, or pass a command to communicate via Unix socket:

emeet-pixy status           # Full status (camera, audio, gesture, PTZ, in-call, auto)
emeet-pixy track            # Enable face tracking
emeet-pixy idle             # Set camera to idle
emeet-pixy privacy          # Enable privacy mode
emeet-pixy toggle-privacy   # Toggle privacy mode
emeet-pixy center           # Center camera (pan=0, tilt=0, zoom=100)
emeet-pixy audio [mode]     # Cycle or set audio mode (nc, live, org)
emeet-pixy gesture-on       # Enable gesture control
emeet-pixy gesture-off      # Disable gesture control
emeet-pixy toggle-gesture   # Toggle gesture control
emeet-pixy auto [mode]      # Set auto mode (off, full, tracking-only, privacy-only)
emeet-pixy auto-on          # Enable full auto mode
emeet-pixy auto-off         # Disable auto mode
emeet-pixy toggle-auto      # Toggle auto mode
emeet-pixy pan <value>      # Set pan (−150 to 150; or rel+/-N for relative)
emeet-pixy tilt <value>     # Set tilt (−90 to 90; or rel+/-N for relative)
emeet-pixy zoom <value>     # Set zoom (100 to 150; or rel+/-N for relative)
emeet-pixy sync             # Sync daemon state from camera hardware
emeet-pixy probe            # Re-detect device (video + hidraw)
emeet-pixy device           # Show current video device path
emeet-pixy waybar           # Output Waybar JSON

Auto Modes

The daemon supports four auto-management strategies:

Mode	On call start	On call end
`full` (default)	Face tracking + noise cancellation + PipeWire source switch	Privacy mode
`tracking-only`	Face tracking	Privacy mode
`privacy-only`	Nothing	Privacy mode
`off`	Nothing	Nothing

Web UI

The daemon serves a dark-themed control panel at http://127.0.0.1:8090 with:

Live MJPEG camera preview (full-width hero)
Camera mode cards (Track / Idle / Privacy) with SVG icons and keyboard shortcuts (T / I / P / C)
Audio mode selector (Noise Cancel / Live / Original)
PTZ sliders (pan ±150°, tilt ±90°, zoom 100–150×) with a spatial position radar
Snapshot button to capture still frames
Preset save/load/delete chips
Gesture control and auto-mode toggles
Toast notifications for state changes
Live updates via SSE (Server-Sent Events)

Configuration

Environment Variables

All config is via environment variables (no CLI flags — os.Args is reserved for socket commands):

Variable	Default	Description
`EMEET_PIXYD_STATE_DIR`	`/run/emeet-pixyd`	Runtime state directory (socket + state.json)
`EMEET_PIXYD_WEB_ADDR`	`127.0.0.1:8090`	Web UI listen address (localhost only)
`EMEET_PIXYD_POLL_INTERVAL`	`2s`	Call detection polling interval (Go duration)
`EMEET_PIXYD_DEBOUNCE_COUNT`	`3`	Consecutive polls before state change
`EMEET_PIXYD_DEBUG`	`false`	Enable pprof endpoints at `/debug/pprof/`
`EMEET_PIXYD_AUTO`	`full`	Auto mode: off, full, tracking-only, privacy-only (legacy: true/1, false/0)
`EMEET_PIXYD_DEFAULT_AUDIO`	`nc`	Default audio mode: nc, live, org

NixOS Module Options

Option	Type	Default	Description
`hardware.emeet-pixy.enable`	bool	`false`	Enable the daemon
`hardware.emeet-pixy.user`	string	`"lars"`	User owning the runtime state directory
`hardware.emeet-pixy.auto`	enum	`"full"`	Auto-management strategy
`hardware.emeet-pixy.defaultAudio`	enum	`"nc"`	Default audio mode
`hardware.emeet-pixy.debug`	bool	`false`	Enable debug mode

Runtime Dependencies

The daemon integrates with these Linux tools (all provided by the NixOS module):

Tool	Purpose	Required
`v4l2-ctl`	Pan/tilt/zoom control via V4L2	Yes
`ffmpeg`	MJPEG streaming in web UI	For preview only
`wpctl`	PipeWire default source switching	For audio switching
`notify-send`	Desktop notifications	Optional

Architecture

main() → NewDaemon() → Run()
  ├── Unix socket listener    Command routing (status, track, privacy, PTZ, …)
  ├── HTTP server              Web UI + API + Prometheus /metrics
  ├── Polling ticker (2s)      /proc scanning → call detection + debounce
  ├── Netlink uevent listener  USB hotplug detection
  └── systemd sd_notify        READY=1 + WATCHDOG=1

Source Layout

main.go             Entry point, daemon lifecycle, signal handling, status/waybar output
commands.go         Command routing (socket + CLI), PTZ/audio/auto/gesture handlers
handlers.go         HTTP routing, web handlers, toast propagation, PTZ axis lookup table
metrics.go          OTel metrics registration and updates
stream.go           MJPEG streaming, snapshot, JPEG frame extraction, checkDevice guard
middleware.go       Middleware variable assignments (implementations live in http.go)
sse.go              SSE-only: Broadcaster (thread-safe fan-out), per-client SSE, event helpers
http.go             HTTP helpers: writeJSON, middleware chain, security/request/logging middleware
ptz.go              PTZ logic: parsePTZValue, axis dispatch, V4L2 control via v4l2-ctl
hid.go              HID bidirectional communication (config/query over hidraw)
device.go           HID device state management: setDeviceState, setTracking/Audio/Gesture, centerCamera
process.go          /proc scanning for call detection, PipeWire, notifications
uevent.go           Netlink uevent listener for hotplug (context-cancellable)
uevent_linux.go     Low-level unix.Socket for netlink
auto.go             Auto-manage loop, call start/end, debounce logic
state.go            State persistence (JSON, atomic write via tmpfile + rename)
probe.go            Device probing (sysfs walks for video4linux + hidraw)
commander.go        CommandRunner interface (subprocess logging), realCommandRunner, noopCommandRunner
deps.go             Dependencies struct (CommandRunner + DI function pointers)
waybar.go           Waybar integration: waybarJSON struct, tooltip builder
web_types.go        webStatus struct shared between handlers and templates
errors.go           CommandError type, CommandResult, exported sentinel errors
cache.go            Named cache types: lastFrameCache, ptzCache (encapsulated mutex access)
templates.templ     HTML templates (compiled via templ generate)
internal/pixy/      Shared types: Config, State, CameraState, AudioMode, PID, SourceID, PTZ constants
static/             Frontend assets (DataStar, app.js, style.css) — go:embed

Key Design Decisions

HID protocol: Commands are 9-byte config reports followed by a commit report with a 200ms inter-report delay. Responses are 64-byte reads parsed by byte position.
State persistence: JSON file at {StateDir}/state.json, atomic write via .tmp + rename. Loaded state always wins over defaults.
Call detection: Scans /proc/*/fd for processes holding the video device open, excluding self and descendants. Debounced (default 3 cycles × 2s = 6s).
Dependency injection: All external interactions (HID, v4l2, PipeWire, notifications) are function fields on Daemon, enabling full test injectability without interfaces.
Branded types: PID and SourceID use phantom-type branding to prevent mixing process IDs and PipeWire source IDs at compile time.

Troubleshooting

Problem	Solution
`PIXY not connected`	Check USB connection, run `lsusb \| grep 328f`. Ensure udev rules are loaded.
`Permission denied` on hidraw	Verify udev rules match vendor `328f` product `00c0`. Run `udevadm control --reload-rules`.
`v4l2-ctl: command not found`	Install `v4l-utils` (provided by NixOS module).
No audio switching	Check `wpctl status` shows a PIXY source. `wpctl` must be in PATH.
Camera not detected after plug-in	Daemon auto-detects via netlink uevents. Check `emeet-pixy probe` output.
Web UI shows "Camera in use"	Another process (e.g., OBS, another browser tab) is holding `/dev/video*` open.
Debounce too slow	Reduce `EMEET_PIXYD_DEBOUNCE_COUNT` (default 3) or `EMEET_PIXYD_POLL_INTERVAL` (default 2s).

Development

nix develop             # Enter dev shell (go, golangci-lint, templ)
nix build               # Build the daemon
templ generate           # Regenerate HTML templates after editing .templ

# Test (use GOWORK=off — parent go.work doesn't include this project)
GOWORK=off go test -race -count=1 ./...

# Lint
GOWORK=off golangci-lint run --timeout 2m ./...

License

MIT — see LICENSE.

Full documentation at emeet-pixyd.lars.software

Name		Name	Last commit message	Last commit date
Latest commit History 541 Commits
.config		.config
.github/workflows		.github/workflows
docs		docs
internal/pixy		internal/pixy
modules		modules
static		static
website		website
.editorconfig		.editorconfig
.envrc		.envrc
.gitattributes		.gitattributes
.gitignore		.gitignore
.golangci.yml		.golangci.yml
AGENTS.md		AGENTS.md
AUTHORS		AUTHORS
CHANGELOG.md		CHANGELOG.md
CONTRIBUTING.md		CONTRIBUTING.md
DESIGN.md		DESIGN.md
FEATURES.md		FEATURES.md
LICENSE		LICENSE
PRODUCT.md		PRODUCT.md
README.md		README.md
ROADMAP.md		ROADMAP.md
TODO_LIST.md		TODO_LIST.md
auto.go		auto.go
auto_cmd_test.go		auto_cmd_test.go
auto_manage_test.go		auto_manage_test.go
auto_test.go		auto_test.go
behavior_auto_test.go		behavior_auto_test.go
behavior_ptz_test.go		behavior_ptz_test.go
behavior_test.go		behavior_test.go
benchmark_test.go		benchmark_test.go
cache.go		cache.go
commander.go		commander.go
commands.go		commands.go
commands_extra_test.go		commands_extra_test.go
commands_test.go		commands_test.go
config_test.go		config_test.go
datastar_fuzz_test.go		datastar_fuzz_test.go
deps.go		deps.go
device.go		device.go
errorfamily.go		errorfamily.go
errorfamily_test.go		errorfamily_test.go
errors.go		errors.go
fake_device_test.go		fake_device_test.go
flake.lock		flake.lock
flake.nix		flake.nix
gesture_audio_test.go		gesture_audio_test.go
git-town.toml		git-town.toml
go.mod		go.mod
go.sum		go.sum
handlers.go		handlers.go
handlers_fuzz_test.go		handlers_fuzz_test.go
handlers_test.go		handlers_test.go
hid.go		hid.go
hid_fuzz_test.go		hid_fuzz_test.go
hid_test.go		hid_test.go
http.go		http.go
integration_auto_test.go		integration_auto_test.go
integration_cmd_test.go		integration_cmd_test.go
integration_hardware_test.go		integration_hardware_test.go
integration_test.go		integration_test.go
jpeg_test.go		jpeg_test.go
main.go		main.go
main_test.go		main_test.go
metrics.go		metrics.go
metrics_test.go		metrics_test.go
middleware.go		middleware.go
middleware_test.go		middleware_test.go
package.nix		package.nix
pixy_simulator_fuzz_test.go		pixy_simulator_fuzz_test.go
pixy_simulator_impl_test.go		pixy_simulator_impl_test.go
pixy_simulator_test.go		pixy_simulator_test.go
preset_test.go		preset_test.go
probe.go		probe.go
probe_hidraw_test.go		probe_hidraw_test.go
probe_video_test.go		probe_video_test.go
process.go		process.go
process_test.go		process_test.go
ptz.go		ptz.go
ptz_cmd_test.go		ptz_cmd_test.go
ptz_fuzz_test.go		ptz_fuzz_test.go
ptz_test.go		ptz_test.go
ptz_unit_test.go		ptz_unit_test.go
socket.go		socket.go
socket_test.go		socket_test.go
sse.go		sse.go
sse_test.go		sse_test.go
state.go		state.go
state_test.go		state_test.go
stream.go		stream.go
stream_test.go		stream_test.go
templates.templ		templates.templ
test_assert_test.go		test_assert_test.go
test_helpers_test.go		test_helpers_test.go
uevent.go		uevent.go
uevent_linux.go		uevent_linux.go
uevent_test.go		uevent_test.go
waybar.go		waybar.go
waybar_golden_test.go		waybar_golden_test.go
web_audio_test.go		web_audio_test.go

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emeet-pixyd
_{Auto-activation daemon for the EMEET PIXY dual-camera AI webcam}

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emeet-pixyd Auto-activation daemon for the EMEET PIXY dual-camera AI webcam

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Who is this for?

When NOT to use this

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Features

Quick Start

NixOS (recommended)

Build from Source

Usage

Auto Modes

Web UI

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NixOS Module Options

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Architecture

Source Layout

Key Design Decisions

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emeet-pixyd
_{Auto-activation daemon for the EMEET PIXY dual-camera AI webcam}