AndroidアプリとデバイスとのBluetoothでの通信内容を解析する

AndroidアプリとデバイスとのBluetoothでの通信内容を解析する

AndroidでBluetoothログを取る

WiresharkでBluetoothログ解析

Bluetooth Low Energyのperipheralにコマンドを送る

private val blinkInRed: ByteArray get() { ... }

private val bluetoothAdapter: BluetoothAdapter? by lazy(LazyThreadSafetyMode.NONE) {
  val bluetoothManager = getSystemService(Context.BLUETOOTH_SERVICE) as BluetoothManager
  bluetoothManager.adapter
}

private var scanner: BluetoothLeScanner? = null
private var gatt: BluetoothGatt? = null

fun startScan() {
  scanner = bluetoothAdapter?.bluetoothLeScanner

  val filter = ScanFilter.Builder()
    .setServiceUuid(ParcelUuid(SERVICE_UUID))
    .build()
  val option = ScanSettings.Builder()
    .setScanMode(ScanSettings.SCAN_MODE_LOW_POWER)
    .setCallbackType(ScanSettings.CALLBACK_TYPE_ALL_MATCHES)
    .build()

  // Start searching the service advertised from a device
  // Get the result in `scanCallback` below
  scanner?.startScan(listOf(filter), option, scanCallback)
}

private val scanCallback = object: ScanCallback() {
  override fun onScanResult(
    callbackType: Int,
    result: ScanResult?)
  {
    result?.let {
      // Found the service. Connect to the device
      // Get the connection result in `gattCallback` below
      gatt = it.device.connectGatt(context, false, gattCallback)
    }
  }
}

private val gattCallback = object: BluetoothGattCallback() {
  override fun onConnectionStateChange(
    gatt: BluetoothGatt?,
    status: Int,
    newState: Int)
  {
    if (status == BluetoothGatt.GATT_SUCCESS) {
      when (newState) {
        BluetoothProfile.STATE_CONNECTED -> {
          gatt?.let {
           // Connected to the device. Lookup the service
           // Results come in to `onServicesDiscovered` below
           it.discoverServices()
          }
        }
      }
    }
  }

  override fun onServicesDiscovered(
    gatt: BluetoothGatt,
    status: Int)
  {
    when (status) {
      BluetoothGatt.GATT_SUCCESS -> {
        gatt.getService(SERVICE_UUID)?.let { s ->
          // Found the service. Lookup the characteristic
          s.getCharacteristic(CHARACTERISTIC_UUID)?.let { c ->
          // Set the binary value to the characteristic
            c.setValue(blinkInRed)
            // Write the value to the characteristic
            // This should light up the LED on the snap tag
            gatt?.writeCharacteristic(c)
          }
        }
      }
    }
  }
}

Bluetooth Low Energyにおけるconnectとpairとbond

Let there be light

gatt?.let {
  // Connected to the device. Pair, bond
  it.device.setPin(myJacketPin)
  it.device.createBond()
  // And then lookup the service
  // Results come in to `onServicesDiscovered` below
  it.discoverServices()
}