android-bluetooth

Android Bluetooth reconnect failures often stem from incorrect socket creation order, improper teardown timing, or stale state. Fix this by applying a prioritized socket factory path with proper retry and teardown delays to avoid race conditions.

Detect dropped Bluetooth connections by monitoring I/O read-loop failures and heartbeat signals, using ACL_DISCONNECTED as a backup trigger. Combine this with an idempotent disconnect handler to safely manage the connection state machine and prevent stuck reconnect loops.

Bluetooth scanning requires selecting correct runtime permissions based on the Android version matrix, including BLUETOOTH_SCAN and BLUETOOTH_CONNECT for newer APIs alongside legacy permissions. You must also implement a connected-device foreground service to prevent silent connection failures.

Route discovery versus bonded-device enumeration by checking the paired device list first to skip scanning overhead. If the target device is not bonded, initiate discovery; otherwise, use the existing bond to create the RFCOMM socket directly using the prioritized factory method.

Yes, the approach supports both Classic SPP/RFCOMM and BLE/GATT scenarios. Classic connections use socket creation strategies and state machines, while BLE connections handle GATT discovery, notification setup, and MTU configuration via referenced documentation for race trackers and sensors.

Use reflection to create a Bluetooth socket when standard secure and insecure socket factory methods fail, particularly across different Android versions. Apply reflection as the first attempt in a prioritized path to maximize compatibility with stubborn SPP devices like OBDLink adapters.