Huawei HR Overlay for OBS

Real-time heart rate overlay for OBS Studio, reading data directly from your Huawei Watch or Smartband via Bluetooth LE — no Huawei SDK, no cloud, no phone required.

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How It Works

Huawei Watch/Band
  [HR Data Broadcast ON]
        │ Bluetooth LE (GATT 0x180D)
        ▼
  HuaweiHROverlay.exe (this app)
  ├── BLE Scanner + GATT reader
  ├── WebSocket server  ws://localhost:8765
  └── HTTP server       http://localhost:8764
        │
        ▼
  OBS Browser Source → animated overlay on stream

Your Huawei watch's HR Data Broadcast mode makes it act as a standard BLE Heart Rate Monitor. No Huawei SDK or cloud account is needed.

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Requirements

Important

You must install the .NET 8 Desktop Runtime before running HuaweiHROverlay.exe. The app does not bundle the runtime — this keeps the EXE small (~2 MB).

Requirement	Download
.NET 8 Desktop Runtime (x64)	Download from Microsoft → Run desktop apps → Windows x64
Windows 10 (build 19041+) or Windows 11	—
OBS Studio	obsproject.com
Huawei Watch/Band with HR Data Broadcast	Most GT2/GT3/GT4, Band 6+, Watch Fit series

Quick .NET 8 Runtime Install (PowerShell)

winget install Microsoft.DotNet.DesktopRuntime.8

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Step 1 — Enable HR Data Broadcast on your Huawei watch

⚠️ This step is mandatory. Without it, the watch won't be detected.

1. On your Huawei watch/band, press the side button to open the app list
2. Go to Settings
3. Scroll to HR Data Broadcasts and enable it
4. The watch will start broadcasting HR data over Bluetooth

Note: While HR Data Broadcast is active, the watch may disconnect from the Huawei Health app on your phone. This is normal.

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Step 2 — Pair with Windows (optional but recommended)

1. Open Windows Settings → Bluetooth & devices → Add device
2. Select Bluetooth and wait for your Huawei watch to appear
3. Click it to pair — no PIN needed for most models

The app can also discover and connect to unpaired devices. Pairing first makes reconnection more reliable.

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Step 3 — Run the app

Double-click HuaweiHROverlay.exe — no installation needed.

If Windows shows a SmartScreen warning, click More info → Run anyway. The app is not code-signed (open source, build from source to verify).

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Step 4 — Connect to your watch

1. Click ▶ Scan — your watch should appear within 5–10 seconds
2. Select it from the list
3. Click ⚡ Connect
4. Live BPM will update in the control panel

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Step 5 — Add OBS Browser Source

1. In OBS, click + in the Sources panel → Browser
2. Set URL to: http://localhost:8764/
3. Width: 400, Height: 120
4. "Shutdown source when not visible" → OFF
5. Click OK

The animated heart rate widget appears on your stream!

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Overlay Features

Feature	Details
Animated pulsing heart	Speed dynamically matches BPM
Gradient BPM number	Large, readable, with red glow
Heart rate zones	🔵 Rest (<100) → 🟢 Fat Burn (<130) → 🟡 Cardio (<160) → 🔴 Peak (160+)
Connection indicator	Green dot = connected, grey = disconnected
Auto-reconnect	Overlay reconnects automatically if the app restarts
Transparent background	Works natively with OBS browser source transparency

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Simulator Mode

Check Simulate in the app to generate realistic fake BPM values — great for testing the overlay layout in OBS without your watch nearby.

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Supported Devices

Any device implementing the standard BLE GATT Heart Rate Service (0x180D) will work:

• Huawei Watch GT2 / GT2e / GT2 Pro / GT3 / GT3 Pro / GT3 SE / GT4 / GT5 / GT5 Pro / GT6 / GT6 Pro
• Huawei Watch Ultimate / Ultimate Design / Ultimate 2
• Huawei Watch Fit / Fit Elegant / Fit 2 / Fit 3 / Fit 4 / Fit 4 Pro / Fit 5
• Huawei Band 6 / 7 / 7 Pro / 8 / 9 / 10 / 10 Pro / 11 / 11 Pro
• Any standard BLE HR chest strap (Polar H10, Wahoo TICKR, etc.)

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Ports Used

Service	Address
Overlay page (OBS Browser Source)	http://localhost:8764/
WebSocket BPM stream	ws://localhost:8765/
Status JSON	http://localhost:8764/status

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Building from Source

Requires .NET 8 SDK (download).

# Debug build + run
cd HuaweiHROverlay
dotnet run

# Release single-file EXE (requires .NET 8 Runtime on target machine)
dotnet publish -c Release -o ./publish
# Output: ./publish/HuaweiHROverlay.exe

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Troubleshooting

Watch not appearing in scan:

• Ensure HR Data Broadcast is enabled on the watch (it can time out — re-enable if needed)
• Click Stop then Scan again
• Try toggling Bluetooth off/on on the PC

"Heart Rate Service not found":

• HR Data Broadcast may have timed out — go back to watch Settings and re-enable it
• The watch may not support HR Data Broadcast (check your model)

OBS overlay shows "--":

• Ensure the app is running and BPM is showing in the control panel
• Check the URL is exactly http://localhost:8764/ (no HTTPS)
• Click Refresh on the OBS Browser Source

Windows Firewall prompt:

• Allow the app on Private networks — it only uses localhost, never the internet

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Architecture

HuaweiHROverlay/
├── Core/
│   ├── BleHeartRateService.cs   # BLE advertisement scanner + GATT reader
│   ├── WebSocketServer.cs       # WS broadcast server (port 8765)
│   ├── HttpOverlayServer.cs     # HTTP server for overlay (port 8764)
│   └── HeartRateReading.cs      # Data model
├── Assets/
│   ├── overlay.html             # Animated OBS overlay (embedded in EXE)
│   └── heart.ico                # App icon
├── Resources/
│   └── Styles.xaml              # WPF dark theme
├── MainWindow.xaml              # Control panel UI
└── MainWindow.xaml.cs           # App logic