bt-lock-guard

Locks your KDE screen when your Bluetooth device (phone/watch) leaves range. Shows a system tray icon with real-time signal graph, toggle switch, and threshold slider.

Phone moves away → RSSI drops below threshold
        ↓
bt-lock-daemon detects N consecutive misses
        ↓
Screen locks (qdbus / loginctl)
        ↓
Phone returns → unlock → grace period → monitoring resumes

Features

• System tray icon (near Wi-Fi/clock in KDE panel)
• Click → popup with:
  • Toggle switch — enable / disable guard instantly
  • Threshold slider — set lock distance (-100 to -30 dBm)
  • Real-time RSSI graph — 60-second history with dBm values
• Per-session config — changes take effect immediately
• Grace period after unlock (lets Bluetooth reconnect before re-arming)
• Works with any Bluetooth device: phone, watch, tag

Install

One-liner (Arch/Manjaro, Debian/Ubuntu/Kali, Fedora)

curl -fsSL https://raw.githubusercontent.com/SolVerNA/bt-lock-guard/master/install.sh | sudo bash

The installer:

1. Detects your package manager and installs dependencies
2. Scans for nearby Bluetooth devices and shows a numbered list
3. You pick your phone/watch by number — no manual MAC entry needed
4. Starts the daemon and tray automatically

From source

git clone https://github.com/SolVerNA/bt-lock-guard
cd bt-lock-guard
# Install files + start tray, then pick device from GUI:
sudo make install
# — or specify MAC directly:
sudo make install MAC=AA:BB:CC:DD:EE:FF

Arch Linux / Manjaro (manual)

sudo pacman -S bluez bluez-utils python-pyqt5 python-dbus
sudo systemctl enable --now bluetooth.service
git clone https://github.com/SolVerNA/bt-lock-guard
cd bt-lock-guard
sudo make install MAC=AA:BB:CC:DD:EE:FF

Debian / Ubuntu / Kali (manual)

sudo apt-get install bluez python3-pyqt5 python3-dbus
git clone https://github.com/SolVerNA/bt-lock-guard
cd bt-lock-guard
sudo make install MAC=AA:BB:CC:DD:EE:FF

Changing device from the tray

Click the tray icon → "Scan & pick device" at the bottom of the popup.
The tray will scan for 8 seconds, show a list of nearby Bluetooth devices, and let you switch with one click — no reinstall needed.

Requirements

Package	Arch / Manjaro	Debian / Ubuntu
Bluetooth daemon + tools	bluez	bluez
l2ping, hcitool	bluez-utils	included in bluez
Qt5 tray UI	python-pyqt5	python3-pyqt5
D-Bus bindings	python-dbus	python3-dbus

• systemd + KDE Plasma (X11 or Wayland)

Threshold guide

dBm	Distance (approx)	Use case
-40	~1m (same room)	Very tight — desk only
-60	~3–5m	Same room
-70	~5–10m	Leave room
-80	~10–15m	Leave apartment
-90	~20m+	Leave building

Start at -80 dBm and adjust using the live graph in the tray popup.

Logs

# Daemon
journalctl --user -u bt-lock-daemon@AA:BB:CC:DD:EE:FF -f

# Tray
journalctl --user -u bt-lock-tray -f

Uninstall

git clone https://github.com/SolVerNA/bt-lock-guard
cd bt-lock-guard
sudo make uninstall

Or if you already have the repo cloned:

sudo make uninstall

Config is kept at ~/.config/bt-lock-guard/config.json.

License

MIT — SolVerNA