When CoreBluetooth renegotiates connection parameters (common at edge-of-range),
it can invalidate cached CBCharacteristic references, causing the characteristics
dictionary to return nil mid-write. This resulted in "FFE2 characteristic lost
during write" failures.
Changes:
- Add resolveCharacteristic() with live service fallback when cache misses
- Implement peripheral(_:didModifyServices:) to handle service invalidation
- Replace all direct characteristics[] lookups with resolveCharacteristic()
- Eliminates force-unwrap on FFE1 notification subscribe
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Schwifty
37e3364e1e
