BLE GATT'ye bağlandıktan sonra sunucusu kullanıyorsanız hangi hizmetlerin kullanılabileceğini öğrenmek için bağlantıyı yapabilir ve belirli bir GATT karakteristiği tespit edildiğinde bildirim isteğinde bulunabilir. anlamına gelir.
Hizmetleri keşfedin
BDE cihazından GATT sunucusuna bağlandıktan sonra yapılacak ilk şey
hizmet keşfi yapmak için kullanılır. Bu, hizmetler hakkında bilgi sağlar
erişimi ve hizmet özellikleri ile bunların ortak kullanım
tanımlar. Aşağıdaki örnekte, hizmet
(Bu çağrı, kullanıcıya yapılan uygun çağrıyla
onConnectionStateChange()
fonksiyonu
BluetoothGattCallback
),
"the"
discoverServices()
işlevi, BDE cihazındaki bilgileri sorgular.
Hizmetin
onServicesDiscovered()
fonksiyonunu
BluetoothGattCallback
.
Bu işlev, cihaz, kullanılabilir hizmetleri hakkında rapor oluşturduğunda çağrılır.
Kotlin
class BluetoothLeService : Service() { ... private val bluetoothGattCallback = object : BluetoothGattCallback() { override fun onConnectionStateChange(gatt: BluetoothGatt?, status: Int, newState: Int) { if (newState == BluetoothProfile.STATE_CONNECTED) { // successfully connected to the GATT Server broadcastUpdate(ACTION_GATT_CONNECTED) connectionState = STATE_CONNECTED // Attempts to discover services after successful connection. bluetoothGatt?.discoverServices() } else if (newState == BluetoothProfile.STATE_DISCONNECTED) { // disconnected from the GATT Server broadcastUpdate(ACTION_GATT_DISCONNECTED) connectionState = STATE_DISCONNECTED } } override fun onServicesDiscovered(gatt: BluetoothGatt?, status: Int) { if (status == BluetoothGatt.GATT_SUCCESS) { broadcastUpdate(ACTION_GATT_SERVICES_DISCOVERED) } else { Log.w(BluetoothLeService.TAG, "onServicesDiscovered received: $status") } } } ... companion object { const val ACTION_GATT_CONNECTED = "com.example.bluetooth.le.ACTION_GATT_CONNECTED" const val ACTION_GATT_DISCONNECTED = "com.example.bluetooth.le.ACTION_GATT_DISCONNECTED" const val ACTION_GATT_SERVICES_DISCOVERED = "com.example.bluetooth.le.ACTION_GATT_SERVICES_DISCOVERED" private const val STATE_DISCONNECTED = 0 private const val STATE_CONNECTED = 2 }
Java
class BluetoothLeService extends Service { public final static String ACTION_GATT_SERVICES_DISCOVERED = "com.example.bluetooth.le.ACTION_GATT_SERVICES_DISCOVERED"; ... private final BluetoothGattCallback bluetoothGattCallback = new BluetoothGattCallback() { @Override public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) { if (newState == BluetoothProfile.STATE_CONNECTED) { // successfully connected to the GATT Server connectionState = STATE_CONNECTED; broadcastUpdate(ACTION_GATT_CONNECTED); // Attempts to discover services after successful connection. bluetoothGatt.discoverServices(); } else if (newState == BluetoothProfile.STATE_DISCONNECTED) { // disconnected from the GATT Server connectionState = STATE_DISCONNECTED; broadcastUpdate(ACTION_GATT_DISCONNECTED); } } @Override public void onServicesDiscovered(BluetoothGatt gatt, int status) { if (status == BluetoothGatt.GATT_SUCCESS) { broadcastUpdate(ACTION_GATT_SERVICES_DISCOVERED); } else { Log.w(TAG, "onServicesDiscovered received: " + status); } } }; }
Hizmet, yayınları
etkinliği'ne dokunun. Hizmetler keşfedildiğinde hizmet,
getServices()
-
Raporlanan verileri alın.
Kotlin
class BluetoothLeService : Service() { ... fun getSupportedGattServices(): List<BluetoothGattService?>? { return bluetoothGatt?.services } }
Java
class BluetoothLeService extends Service { ... public List<BluetoothGattService> getSupportedGattServices() { if (bluetoothGatt == null) return null; return bluetoothGatt.getServices(); } }
Ardından etkinlik, yayın amacını aldığında bu işlevi çağırabilir. gösteren bir uyarı simgesi içerir.
Kotlin
class DeviceControlActivity : AppCompatActivity() { ... private val gattUpdateReceiver: BroadcastReceiver = object : BroadcastReceiver() { override fun onReceive(context: Context, intent: Intent) { when (intent.action) { BluetoothLeService.ACTION_GATT_CONNECTED -> { connected = true updateConnectionState(R.string.connected) } BluetoothLeService.ACTION_GATT_DISCONNECTED -> { connected = false updateConnectionState(R.string.disconnected) } BluetoothLeService.ACTION_GATT_SERVICES_DISCOVERED -> { // Show all the supported services and characteristics on the user interface. displayGattServices(bluetoothService?.getSupportedGattServices()) } } } } }
Java
class DeviceControlsActivity extends AppCompatActivity { ... private final BroadcastReceiver gattUpdateReceiver = new BroadcastReceiver() { @Override public void onReceive(Context context, Intent intent) { final String action = intent.getAction(); if (BluetoothLeService.ACTION_GATT_CONNECTED.equals(action)) { connected = true; updateConnectionState(R.string.connected); } else if (BluetoothLeService.ACTION_GATT_DISCONNECTED.equals(action)) { connected = false; updateConnectionState(R.string.disconnected); } else if (BluetoothLeService.ACTION_GATT_SERVICES_DISCOVERED.equals(action)) { // Show all the supported services and characteristics on the user interface. displayGattServices(bluetoothService.getSupportedGattServices()); } } }; }
BDE özelliklerini okuma
Uygulamanız bir GATT sunucusuna bağlanıp hizmetleri keşfettikten sonra desteklenen durumlarda özellikleri okuyabilir ve yazabilir. Örneğin, snippet, sunucunun hizmetleri ve özellikleri ile görünümlerinde yinelenir bunları kullanıcı arayüzünde görebilirsiniz:
Kotlin
class DeviceControlActivity : Activity() { // Demonstrates how to iterate through the supported GATT // Services/Characteristics. // In this sample, we populate the data structure that is bound to the // ExpandableListView on the UI. private fun displayGattServices(gattServices: List<BluetoothGattService>?) { if (gattServices == null) return var uuid: String? val unknownServiceString: String = resources.getString(R.string.unknown_service) val unknownCharaString: String = resources.getString(R.string.unknown_characteristic) val gattServiceData: MutableList<HashMap<String, String>> = mutableListOf() val gattCharacteristicData: MutableList<ArrayList<HashMap<String, String>>> = mutableListOf() mGattCharacteristics = mutableListOf() // Loops through available GATT Services. gattServices.forEach { gattService -> val currentServiceData = HashMap<String, String>() uuid = gattService.uuid.toString() currentServiceData[LIST_NAME] = SampleGattAttributes.lookup(uuid, unknownServiceString) currentServiceData[LIST_UUID] = uuid gattServiceData += currentServiceData val gattCharacteristicGroupData: ArrayList<HashMap<String, String>> = arrayListOf() val gattCharacteristics = gattService.characteristics val charas: MutableList<BluetoothGattCharacteristic> = mutableListOf() // Loops through available Characteristics. gattCharacteristics.forEach { gattCharacteristic -> charas += gattCharacteristic val currentCharaData: HashMap<String, String> = hashMapOf() uuid = gattCharacteristic.uuid.toString() currentCharaData[LIST_NAME] = SampleGattAttributes.lookup(uuid, unknownCharaString) currentCharaData[LIST_UUID] = uuid gattCharacteristicGroupData += currentCharaData } mGattCharacteristics += charas gattCharacteristicData += gattCharacteristicGroupData } } }
Java
public class DeviceControlActivity extends Activity { ... // Demonstrates how to iterate through the supported GATT // Services/Characteristics. // In this sample, we populate the data structure that is bound to the // ExpandableListView on the UI. private void displayGattServices(List<BluetoothGattService> gattServices) { if (gattServices == null) return; String uuid = null; String unknownServiceString = getResources(). getString(R.string.unknown_service); String unknownCharaString = getResources(). getString(R.string.unknown_characteristic); ArrayList<HashMap<String, String>> gattServiceData = new ArrayList<HashMap<String, String>>(); ArrayList<ArrayList<HashMap<String, String>>> gattCharacteristicData = new ArrayList<ArrayList<HashMap<String, String>>>(); mGattCharacteristics = new ArrayList<ArrayList<BluetoothGattCharacteristic>>(); // Loops through available GATT Services. for (BluetoothGattService gattService : gattServices) { HashMap<String, String> currentServiceData = new HashMap<String, String>(); uuid = gattService.getUuid().toString(); currentServiceData.put( LIST_NAME, SampleGattAttributes. lookup(uuid, unknownServiceString)); currentServiceData.put(LIST_UUID, uuid); gattServiceData.add(currentServiceData); ArrayList<HashMap<String, String>> gattCharacteristicGroupData = new ArrayList<HashMap<String, String>>(); List<BluetoothGattCharacteristic> gattCharacteristics = gattService.getCharacteristics(); ArrayList<BluetoothGattCharacteristic> charas = new ArrayList<BluetoothGattCharacteristic>(); // Loops through available Characteristics. for (BluetoothGattCharacteristic gattCharacteristic : gattCharacteristics) { charas.add(gattCharacteristic); HashMap<String, String> currentCharaData = new HashMap<String, String>(); uuid = gattCharacteristic.getUuid().toString(); currentCharaData.put( LIST_NAME, SampleGattAttributes.lookup(uuid, unknownCharaString)); currentCharaData.put(LIST_UUID, uuid); gattCharacteristicGroupData.add(currentCharaData); } mGattCharacteristics.add(charas); gattCharacteristicData.add(gattCharacteristicGroupData); } ... } ... }
GATT hizmeti, aşağıdaki bağlantıdan okuyabileceğiniz özelliklerin listesini sunar:
olanak tanır. Verileri sorgulamak için
readCharacteristic()
fonksiyonunu
BluetoothGatt
,
BluetoothGattCharacteristic
üzerine düşünün.
Kotlin
class BluetoothLeService : Service() { ... fun readCharacteristic(characteristic: BluetoothGattCharacteristic) { bluetoothGatt?.let { gatt -> gatt.readCharacteristic(characteristic) } ?: run { Log.w(TAG, "BluetoothGatt not initialized") Return } } }
Java
class BluetoothLeService extends Service { ... public void readCharacteristic(BluetoothGattCharacteristic characteristic) { if (bluetoothGatt == null) { Log.w(TAG, "BluetoothGatt not initialized"); return; } bluetoothGatt.readCharacteristic(characteristic); } }
Bu örnekte, hizmet bir öğeyi çağırarak
readCharacteristic()
.
Bu, eşzamansız bir çağrıdır. Sonuçlar Google Görüntülü Reklam Ağı'na
BluetoothGattCallback
işlev
onCharacteristicRead()
.
Kotlin
class BluetoothLeService : Service() { ... private val bluetoothGattCallback = object : BluetoothGattCallback() { ... override fun onCharacteristicRead( gatt: BluetoothGatt, characteristic: BluetoothGattCharacteristic, status: Int ) { if (status == BluetoothGatt.GATT_SUCCESS) { broadcastUpdate(BluetoothLeService.ACTION_DATA_AVAILABLE, characteristic) } } } }
Java
class BluetoothLeService extends Service { ... private final BluetoothGattCallback bluetoothGattCallback = new BluetoothGattCallback() { ... @Override public void onCharacteristicRead( BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status ) { if (status == BluetoothGatt.GATT_SUCCESS) { broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic); } } }; }
Belirli bir geri çağırma tetiklendiğinde, uygun
broadcastUpdate()
yardımcı yöntemi ve bu yönteme bir işlem iletir. Bu verilerin
bu bölümdeki ayrıştırma işlemi, Bluetooth Nabız Ölçümüne uygun olarak gerçekleştirilir
Ölçüm profili spesifikasyonları.
Kotlin
private fun broadcastUpdate(action: String, characteristic: BluetoothGattCharacteristic) { val intent = Intent(action) // This is special handling for the Heart Rate Measurement profile. Data // parsing is carried out as per profile specifications. when (characteristic.uuid) { UUID_HEART_RATE_MEASUREMENT -> { val flag = characteristic.properties val format = when (flag and 0x01) { 0x01 -> { Log.d(TAG, "Heart rate format UINT16.") BluetoothGattCharacteristic.FORMAT_UINT16 } else -> { Log.d(TAG, "Heart rate format UINT8.") BluetoothGattCharacteristic.FORMAT_UINT8 } } val heartRate = characteristic.getIntValue(format, 1) Log.d(TAG, String.format("Received heart rate: %d", heartRate)) intent.putExtra(EXTRA_DATA, (heartRate).toString()) } else -> { // For all other profiles, writes the data formatted in HEX. val data: ByteArray? = characteristic.value if (data?.isNotEmpty() == true) { val hexString: String = data.joinToString(separator = " ") { String.format("%02X", it) } intent.putExtra(EXTRA_DATA, "$data\n$hexString") } } } sendBroadcast(intent) }
Java
private void broadcastUpdate(final String action, final BluetoothGattCharacteristic characteristic) { final Intent intent = new Intent(action); // This is special handling for the Heart Rate Measurement profile. Data // parsing is carried out as per profile specifications. if (UUID_HEART_RATE_MEASUREMENT.equals(characteristic.getUuid())) { int flag = characteristic.getProperties(); int format = -1; if ((flag & 0x01) != 0) { format = BluetoothGattCharacteristic.FORMAT_UINT16; Log.d(TAG, "Heart rate format UINT16."); } else { format = BluetoothGattCharacteristic.FORMAT_UINT8; Log.d(TAG, "Heart rate format UINT8."); } final int heartRate = characteristic.getIntValue(format, 1); Log.d(TAG, String.format("Received heart rate: %d", heartRate)); intent.putExtra(EXTRA_DATA, String.valueOf(heartRate)); } else { // For all other profiles, writes the data formatted in HEX. final byte[] data = characteristic.getValue(); if (data != null && data.length > 0) { final StringBuilder stringBuilder = new StringBuilder(data.length); for(byte byteChar : data) stringBuilder.append(String.format("%02X ", byteChar)); intent.putExtra(EXTRA_DATA, new String(data) + "\n" + stringBuilder.toString()); } } sendBroadcast(intent); }
GATT bildirimlerini alma
BDE uygulamalarının, belirli bir özellik olduğunda bildirim istemesi yaygın bir uygulamadır.
cihazdaki değişiklikleri görebilirsiniz. Aşağıdaki örnekte hizmet,
fonksiyonunu çağırarak
setCharacteristicNotification()
yöntem:
Kotlin
class BluetoothLeService : Service() { ... fun setCharacteristicNotification( characteristic: BluetoothGattCharacteristic, enabled: Boolean ) { bluetoothGatt?.let { gatt -> gatt.setCharacteristicNotification(characteristic, enabled) // This is specific to Heart Rate Measurement. if (BluetoothLeService.UUID_HEART_RATE_MEASUREMENT == characteristic.uuid) { val descriptor = characteristic.getDescriptor(UUID.fromString(SampleGattAttributes.CLIENT_CHARACTERISTIC_CONFIG)) descriptor.value = BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE gatt.writeDescriptor(descriptor) } } ?: run { Log.w(BluetoothLeService.TAG, "BluetoothGatt not initialized") } } }
Java
class BluetoothLeService extends Service { ... public void setCharacteristicNotification(BluetoothGattCharacteristic characteristic,boolean enabled) { if (bluetoothGatt == null) { Log.w(TAG, "BluetoothGatt not initialized"); Return; } bluetoothGatt.setCharacteristicNotification(characteristic, enabled); // This is specific to Heart Rate Measurement. if (UUID_HEART_RATE_MEASUREMENT.equals(characteristic.getUuid())) { BluetoothGattDescriptor descriptor = characteristic.getDescriptor(UUID.fromString(SampleGattAttributes.CLIENT_CHARACTERISTIC_CONFIG)); descriptor.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE); bluetoothGatt.writeDescriptor(descriptor); } } }
Bir özellik için bildirimler etkinleştirildiğinde,
onCharacteristicChanged()
Uzak cihazda özellik değişirse geri çağırma tetiklenir:
Kotlin
class BluetoothLeService : Service() { ... private val bluetoothGattCallback = object : BluetoothGattCallback() { ... override fun onCharacteristicChanged( gatt: BluetoothGatt, characteristic: BluetoothGattCharacteristic ) { broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic) } } }
Java
class BluetoothLeService extends Service { ... private final BluetoothGattCallback bluetoothGattCallback = new BluetoothGattCallback() { ... @Override public void onCharacteristicChanged( BluetoothGatt gatt, BluetoothGattCharacteristic characteristic ) { broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic); } }; }