dadaloop82
0a35e9e8b4
The QN-KS sends 18-byte frames on FFF1 with opcode 0x10: [0x10][0x12=len][...][flags][weight_hi][weight_lo][...][crc] Weight is u16BE at bytes 9-10 in grams (1g resolution). Stable flag is bit 3 of byte[8] (0xF8=stable, 0xF0=settling). Checksum = sum(bytes[0..16]) mod 256. The generic parser was reading byte[1]=0x12=18 as '18 grams' (the packet length field), which is why it always showed 18g. Added parseQNFood() with CRC validation, detected before generic fallback. Also added AE00/AE02 UUIDs (secondary notifiable service on QN-KS).
EverShelf Scale Gateway
Android gateway app that bridges Bluetooth LE smart scales with EverShelf via WebSocket.
How it works
Smart Scale ──(BLE)──► Android Gateway App ──(WebSocket/LAN)──► EverShelf (browser)
The app runs a local WebSocket server (port 8765) on your Android device. EverShelf connects to it over your home Wi-Fi and receives weight readings in real time.
Supported scale protocols
| Protocol | Service UUID | Notes |
|---|---|---|
| Bluetooth SIG Weight Scale | 0x181D / char 0x2A9D |
Most compatible; works with most smart scales |
| Bluetooth SIG Body Composition | 0x181B / char 0x2A9C |
Reports weight + body fat %, BMI |
| Generic fallback | Any notifiable characteristic | Auto-heuristic parsing for 100+ models |
Verified compatible scales (community list)
- Xiaomi Mi Body Composition Scale 2
- Renpho Smart Body Fat Scale
- INEVIFIT Smart Body Fat Scale
- Any OpenScale-compatible scale (see openScale supported devices)
Your scale (B09MRXVBV6): If it implements the standard BLE Weight Scale or Body Composition profile (very likely for modern Amazon smart scales), the gateway will connect automatically. If not, check the openScale wiki and open an issue.
Download
Download the latest APK directly: evershelf-scale-gateway.apk
Requirements
- Android 7.0 (API 24) or later
- Bluetooth LE (BLE) support
- Both the Android device and the device running EverShelf must be on the same Wi-Fi network
Setup (step by step)
1. Install the APK
Download and install the APK from the Releases page. You may need to allow "Install from unknown sources" in Android settings.
2. Launch the app
The app starts the WebSocket gateway server immediately. You will see the gateway URL (e.g. ws://192.168.1.100:8765) at the top.
3. Connect your scale
Tap "Cerca Bilance Bluetooth" (Find Bluetooth Scales). Make sure your scale is turned on. Tap it in the list to connect.
4. Configure EverShelf
In EverShelf → ⚙️ Settings → ⚖️ Bilancia Smart:
- Enable the toggle
- Paste the gateway URL shown in the Android app
- Tap "Testa connessione" — you should see ✅
5. Use it
When adding or consuming a product with unit g or ml, a "⚖️ Leggi dalla bilancia" button appears. Tap it, place the product on the scale, and the weight is filled in automatically.
WebSocket protocol reference
All messages are JSON. The server sends these to connected clients:
// Scale status update
{"type":"status","state":"connected","device":"Mi Scale 2","battery":85}
{"type":"status","state":"disconnected"}
// Weight reading (broadcast continuously while scale is active)
{"type":"weight","value":72.50,"unit":"kg","stable":true,"timestamp":1712345678000}
// Response to ping
{"type":"pong"}
Clients can send:
{"type":"get_status"} // Request current status
{"type":"get_weight"} // Request next stable weight reading
{"type":"ping"} // Keep-alive
Build from source
Prerequisites
- Android Studio Hedgehog (2023.1) or later
- Java 8+
Steps
# 1. Clone the repo
git clone https://github.com/dadaloop82/EverShelf.git
cd EverShelf/evershelf-scale-gateway
# 2. Download the Gradle wrapper (if not included)
gradle wrapper --gradle-version 8.4
# 3. Build debug APK
./gradlew assembleDebug
# APK is at: app/build/outputs/apk/debug/app-debug.apk
Project structure
evershelf-scale-gateway/
├── app/src/main/
│ ├── kotlin/it/dadaloop/evershelf/scalegate/
│ │ ├── MainActivity.kt — UI, orchestration
│ │ ├── BleScaleManager.kt — BLE scanning & GATT connection
│ │ ├── ScaleProtocol.kt — Parsing for all supported protocols
│ │ └── GatewayWebSocketServer.kt — WebSocket server (Java-WebSocket)
│ ├── res/layout/
│ │ ├── activity_main.xml
│ │ └── item_device.xml
│ └── AndroidManifest.xml
├── build.gradle.kts
└── settings.gradle.kts
License
MIT — see LICENSE