feat: Merge SaltyTag BLE — GPS/IMU streaming to UWB tag, anchor display, UWB position authority
BLE Protocol (from SaltyTag Flutter app, exact binary format):
Service: 12345678-1234-5678-1234-56789abcdef0
GPS char: …def3 IMU char: …def4 Ranging char: …def5 (notify)
BLEManager.swift — CoreBluetooth central:
- Scans for peripherals advertising the service UUID; name prefix "UWB_TAG"
- 15 s scan timeout, auto-reconnect with 2 s backoff on disconnect
- Exposes sendGPS(Data) + sendIMU(Data); gpsStreamEnabled / imuStreamEnabled toggles
- Subscribes to ranging notifications → parses → publishes anchors[]
BLEPackets.swift — exact binary encoders matching SaltyTag firmware expectations:
- gpsPacket(CLLocation) → 20 bytes LE: lat×1e7, lon×1e7, alt×10(Int16),
speed×100(UInt16), heading×100(UInt16), accuracy×10(UInt8), fix_type, ts_ms_low32
- imuPacket(CMDeviceMotion) → 22 bytes LE: accel XYZ milli-g (already in g from CoreMotion),
gyro XYZ centi-deg/s (rad/s × 5729.578), mag XYZ μT, ts_ms_low32
- parseRanging(Data) → [AnchorInfo]: count byte + 9 bytes/anchor
(index, Int32-mm range, Int16×10 RSSI, UInt16 age_ms)
AnchorInfo.swift — anchor model with 3 s staleness check
BLEStatusView.swift — "BLE Tag" tab (3rd tab in ContentView):
- Connection card: state dot, peripheral name, Scan/Stop/Disconnect button
- GPS→Tag and IMU→Tag streaming toggles (5 Hz / 10 Hz rates shown)
- Anchor list matching SaltyTag UI: freshness dot, A{id} label, range, RSSI, STALE badge
Green label if <5 m, orange if ≥5 m, gray if stale
SensorManager:
- Owns BLEManager; observes connectionState via Combine → starts/stops BLE timers
- BLE GPS timer: 200 ms (5 Hz), sends lastKnownLocation via BLEPackets.gpsPacket
- BLE IMU timer: 100 ms (10 Hz), sends lastKnownMotion via BLEPackets.imuPacket
- lastKnownMotion updated from 100 Hz CMDeviceMotion callback
- ensureSensorsRunning() called on BLE connect (sensors start even without Follow-Me)
- Subscribes to saltybot/uwb/tag/position — Orin-fused phone absolute position
(robot RTK GPS + UWB tag offset = cm-accurate phone position)
Phone position source hierarchy (updateBestPhonePosition):
1. saltybot/uwb/tag/position fresh < 3 s → UWB authority (more accurate than phone GPS)
2. CoreLocation GPS fallback
- phonePositionSource: PhonePositionSource (.uwb(accuracyM) | .gps(accuracyM))
- userLocation always set to best source; MQTT publish to saltybot/ios/gps unchanged
MapContentView:
- positionSourceBadge (top-left, below UWB badge): "Position: UWB 2cm" or "Position: GPS 5m"
with waveform icon (UWB) or location icon (GPS)
Info.plist:
- NSBluetoothAlwaysUsageDescription added
- NSMotionUsageDescription updated (SAUL-T-MOTE branding)
- UIBackgroundModes: added bluetooth-central
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
sl-ios
c472668d7a