Core Bluetooth

What to open

• Use

  corebluetooth/AboutCoreBluetooth.md

  and

  corebluetooth/CoreBluetoothOverview.md

  for concepts and role orientation.
• Use

  corebluetooth/PerformingCommonCentralRoleTasks.md

  for step-by-step central workflows.
• Use

  corebluetooth/PerformingCommonPeripheralRoleTasks.md

  for step-by-step peripheral workflows.
• Use

  corebluetooth/BestPracticesforInteractingwithaRemotePeripheralDevice.md

  and

  corebluetooth/BestPracticesforSettingUpYourLocalDeviceasaPeripheral.md

  for pitfalls and best practices.
• Use

  corebluetooth/CoreBluetoothBackgroundProcessingforiOSApps.md

  for background modes and lifecycle constraints.
• Use

  corebluetooth/BluetoothStateRestorationAppReaunchRules.md

  for state restoration app relaunch rules.
• Use

  corebluetooth/corebluetooth.md

  for API quick maps and symbol lookup.

Workflow

• Identify whether the app acts as a central, a peripheral, or both.
• Wait for the manager state to be

  poweredOn

  before issuing BLE operations.
• Follow the role checklist to keep discovery and connection order correct.
• Open the role task guide and best practices first; use the API reference for exact signatures.

Central checklist

1. Create a

   CBCentralManager

   with a delegate and queue.
2. Handle

   centralManagerDidUpdateState(_:)

   and gate scanning on

   .poweredOn

   .
3. Scan with

   scanForPeripherals(withServices:options:)

   and stop when the target is found.
4. Connect, set the

   CBPeripheral

   delegate, and discover services and characteristics.
5. Read, write, or subscribe to characteristic notifications as needed.

Peripheral checklist

1. Create a

   CBPeripheralManager

   with a delegate and queue.
2. Wait for the state to become

   .poweredOn

   .
3. Define services and characteristics, then add them to the manager.
4. Start advertising with service UUIDs and optional local name.
5. Respond to read and write requests; publish updates to subscribed centrals.

Reminders

• Retain discovered

  CBPeripheral

  instances to keep them alive.
• Use notifications for streaming data; use write-without-response only when

  canSendWriteWithoutResponse

  is true.
• Use L2CAP only for use cases that do not fit GATT characteristics.