Reading encrypted characteristcs returns error 132 but bond state becomes BONDED

[mecoFarid]

I have a simple setup as follows, where I am trying to bond with a host BL device by reading encrypted characteristics. This code sometimes succeeds but fails most of the time.

class BleClient (context: Context): BleManager(context){
  fun connectAdapter(): Flow<ConnectionState> = stateAsFlow().also {
    connect([BluetoothDevice])
      .useAutoConnect(true)
      .enqueue()
  }

  fun bond(): Flow<BondState> =
    bondingStateAsFlow().also {
      readEncryptedCharacteristic()
    }

  private fun readEncryptedCharacteristic() {
    super.readCharacteristic([ENCRYPTED_CHARACTERISTIC]).enqueue()
  }
}

Usage

  val bleClient = BleClient(context)
  // Wait for adapter connection to be ready
  bleClient.connectAdapter().first { it == ConnectionState.Ready }
  // Wait until bonded
  val bonded  =  bleClient.bond().first { it = BondState.Bonded }
  Log.i(TAG, "Bond state: $bonded")

When bleClient.bond().first { it = BondState.Bonded } is executed both host and the client displays a pairing dialog, once I click on "confirm" on both machines. The logcat shows the following logs: How is that even possible that reading encrypted characteristics fails but bond state becomes Bonded?

com.example.app E/BleManager: onCharacteristicRead error 132
com.example.app I/BleClient: Bond state: : no.nordicsemi.android.ble.ktx.state.BondState$Bonded@d9512fe

Note: error 132 means GhattDevice is busy

[philips77]

How is that even possible that reading encrypted characteristics fails but bond state becomes Bonded?

Until around Android 8 the system wasn't automatically repeating a request in case of a lack of authentication. The library tries to do this for you. Have a look at

Android-BLE-Library/ble/src/main/java/no/nordicsemi/android/ble/BleManagerHandler.java

Lines 375 to 396 in b5e9580

	// On older Android versions, after executing a command on secured attribute
	// of a device that is not bonded, let's say a write characteristic operation,
	// the system will start bonding. The BOND_BONDING and BOND_BONDED events will
	// be received, but the command will not be repeated automatically.
	//
	// Test results:
	// Devices that require repeating the last task:
	// - Nexus 4 with Android 5.1.1
	// - Samsung S6 with 5.0.1
	// - Samsung S8 with Android 7.0
	// - Nexus 9 with Android 7.1.1
	// Devices that repeat the request automatically:
	// - Pixel 2 with Android 8.1.0
	// - Samsung S8 with Android 8.0.0
	//
	if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) {
	if (request != null) {
	// Repeat the last command in that case.
	enqueueFirst(request);
	break;
	}
	}

What phone are you testing on, and what is the Android version?
What authentication method do you have on the encrypted characteristic?
Did you make any progress with the issue? Sorry for looking so late into it.

[philips77]

Any updates on this issue?

[mecoFarid]

@philips77 This is now working but, honestly, I have played around with so many parameters that I don't know exactly which setting helped. Just as an example I, definitely, know I'm passing different values to these 2 parameters than I did before. Previously I was passing no flag or true, now passing true to both of them.

ScanSettings.Builder.setUseHardwareBatchingIfSupported(true)
ConnectRequest.useAutoConnect(true)

Can we keep this open until I get some free time to play around to reproduce the issue so we (or you) can resolve it once for all?