如何在android中获取BLE通知？
如何在android中获取BLE通知？
提问于 2014-11-05 21:39:32
我在试着得到定制设备的通知。我知道该设备正在工作，因为在iOS中，使用Lightblue应用程序时，我确实会收到通知。我试过使用nexus 5和三星s4 (都是kitkats)。似乎什么都起不到作用。我的"onCharacteristicChanged“没有被呼叫。
MainActivity.java
package com.foo.ble;
import android.app.Activity;
import android.bluetooth.BluetoothAdapter;
import android.bluetooth.BluetoothDevice;
import android.bluetooth.BluetoothManager;
import android.content.Context;
import android.os.Bundle;
import android.os.Handler;
import android.util.Log;
public class MainActivity extends Activity implements BluetoothAdapter.LeScanCallback {
private BluetoothAdapter adapter;
final private static char[] hexArray = "0123456789ABCDEF".toCharArray();
private Callback callback;
/**
* Converts 0xfe to "FE"
* @return hex representation of the adScanned
*/
public static String getPayload(final byte[] adScanned) {
if (adScanned == null) return "N/A";
final char[] hexChars = new char[adScanned.length * 2];
for (int j = 0; j < adScanned.length; j++) {
final int v = adScanned[j] & 0xFF;
hexChars[j * 2] = hexArray[v >>> 4];
hexChars[j * 2 + 1] = hexArray[v & 0x0F];
}
return new String(hexChars);
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
BluetoothManager manager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
adapter = manager.getAdapter();
callback = new Callback();
Handler handler = new Handler();
handler.postDelayed(new Runnable() {
@Override
public void run() {
adapter.stopLeScan(MainActivity.this);
}
}, 3*10000);
runOnUiThread(new Runnable() {
@Override
public void run() {
adapter.startLeScan(MainActivity.this);
}
});
}
@Override
public void onLeScan(final BluetoothDevice device, final int rssi, final byte[] scanRecord) {
if (device.getAddress().equals("CE:AD:09:F2:BB:DC")) {
Log.d("foo", "onLeScan payload:" + getPayload(scanRecord));
adapter.stopLeScan(this);
runOnUiThread(new Runnable() {
@Override
public void run() {
device.connectGatt(MainActivity.this, true, callback);
}
});
}
}
@Override
protected void onDestroy() {
callback.close();
}
}Callback.java
package com.foo.ble;
import android.bluetooth.BluetoothGatt;
import android.bluetooth.BluetoothGattCallback;
import android.bluetooth.BluetoothGattCharacteristic;
import android.bluetooth.BluetoothGattDescriptor;
import android.bluetooth.BluetoothProfile;
import android.util.Log;
import java.util.UUID;
public class Callback extends BluetoothGattCallback {
final static UUID SERVICE = UUID.fromString("something1");
final static UUID ADV_CHAR = UUID.fromString("something2");
final static UUID ADV_DESCRIPTOR = UUID.fromString("something3");
BluetoothGatt gatt;
public void close() {
if (gatt == null) return;
Log.d("foo", "close with gatt");
gatt.disconnect();
gatt.close();
gatt = null;
}
@Override
public void onConnectionStateChange(final BluetoothGatt gatt, final int status,
final int newState) {
Log.d("foo", "onConnectionStateChange");
if (newState == BluetoothProfile.STATE_CONNECTED) {
Log.d("foo", "status connected");
this.gatt = gatt;
gatt.discoverServices();
}
}
@Override
public void onServicesDiscovered(final BluetoothGatt gatt, final int status) {
Log.d("foo", "onServicesDiscovered");
if (status == BluetoothGatt.GATT_SUCCESS) {
final BluetoothGattCharacteristic characteristic =
gatt.getService(SERVICE).getCharacteristic(ADV_CHAR);
final BluetoothGattDescriptor descriptor =
characteristic.getDescriptor(ADV_DESCRIPTOR);
descriptor.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
gatt.setCharacteristicNotification(characteristic, true);
gatt.writeDescriptor(descriptor);
}
}
@Override
public void onCharacteristicRead(final BluetoothGatt gatt,
final BluetoothGattCharacteristic characteristic,
final int status) {
Log.d("foo", "onCharacteristicRead status:" + status + " payload: " +
MainActivity.getPayload(characteristic.getValue()));
}
@Override
public void onCharacteristicWrite(final BluetoothGatt gatt,
final BluetoothGattCharacteristic characteristic,
final int status) {
Log.d("foo", "onCharacteristicWrite");
}
@Override
public void onCharacteristicChanged(final BluetoothGatt gatt,
final BluetoothGattCharacteristic characteristic) {
Log.d("foo", "onCharacteristicChanged payload:" +
MainActivity.getPayload(characteristic.getValue()));
}
@Override
public void onDescriptorWrite(final BluetoothGatt gatt,
final BluetoothGattDescriptor descriptor,
final int status) {
Log.d("foo", "onDescriptorWrite status: " + status);
final BluetoothGattCharacteristic characteristic =
gatt.getService(SERVICE).getCharacteristic(ADV_CHAR);
if (characteristic.getValue() != null) {
Log.d("foo", "value: " + MainActivity.getPayload(characteristic.getValue()));
} else {
gatt.readCharacteristic(characteristic);
}
}
}我的AndroidManifest.xml有：
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />日志如下所示：
11-05 12:17:13.314 3683-3683/com.foo.ble D/BluetoothAdapter﹕ startLeScan(): null
11-05 12:17:13.364 3683-3695/com.foo.ble D/BluetoothAdapter﹕ onClientRegistered() - status=0 clientIf=5
11-05 12:17:13.394 3683-3683/com.foo.ble I/Adreno-EGL﹕ <qeglDrvAPI_eglInitialize:320>: EGL 1.4 QUALCOMM Build: I0404c4692afb8623f95c43aeb6d5e13ed4b30ddbDate: 11/06/13
11-05 12:17:13.414 3683-3683/com.foo.ble D/OpenGLRenderer﹕ Enabling debug mode 0
11-05 12:17:13.454 3683-3683/com.foo.ble D/dalvikvm﹕ GC_FOR_ALLOC freed 238K, 2% free 16971K/17240K, paused 14ms, total 14ms
11-05 12:17:15.174 3683-3694/com.foo.ble D/foo﹕ onLeScan payload:02010517FF0000000000000005000000000000000000395401001207086C6976656C7911072E9AB04DB9790F857A4CF0634C7AB94A000000000000000000
11-05 12:17:15.174 3683-3694/com.foo.ble D/BluetoothAdapter﹕ stopLeScan()
11-05 12:17:15.184 3683-3683/com.foo.ble D/BluetoothGatt﹕ connect() - device: CE:AD:09:F2:BB:DC, auto: true
11-05 12:17:15.184 3683-3683/com.foo.ble D/BluetoothGatt﹕ registerApp()
11-05 12:17:15.184 3683-3683/com.foo.ble D/BluetoothGatt﹕ registerApp() - UUID=605cbd6f-6080-4fd8-97ff-1f97b406258e
11-05 12:17:15.194 3683-3695/com.foo.ble D/BluetoothGatt﹕ onClientRegistered() - status=0 clientIf=5
11-05 12:17:43.344 3683-3683/com.foo.ble D/BluetoothAdapter﹕ stopLeScan()
11-05 12:23:59.194 3683-3694/com.foo.ble D/BluetoothGatt﹕ onClientConnectionState() - status=0 clientIf=5 device=CE:AD:09:F2:BB:DC
11-05 12:23:59.194 3683-3694/com.foo.ble D/foo﹕ onConnectionStateChange
11-05 12:23:59.204 3683-3694/com.foo.ble D/foo﹕ status connected
11-05 12:23:59.204 3683-3694/com.foo.ble D/BluetoothGatt﹕ discoverServices() - device: CE:AD:09:F2:BB:DC
11-05 12:24:00.754 3683-3695/com.foo.ble D/BluetoothGatt﹕ onGetService() - Device=CE:AD:09:F2:BB:DC UUID=randomService1
11-05 12:24:00.764 3683-3694/com.foo.ble D/BluetoothGatt﹕ onGetService() - Device=CE:AD:09:F2:BB:DC UUID=randomService2
11-05 12:24:00.784 3683-3695/com.foo.ble D/BluetoothGatt﹕ onGetService() - Device=CE:AD:09:F2:BB:DC UUID=something1
11-05 12:24:00.794 3683-3694/com.foo.ble D/BluetoothGatt﹕ onGetCharacteristic() - Device=CE:AD:09:F2:BB:DC UUID=randomUUID1
11-05 12:24:00.804 3683-3695/com.foo.ble D/BluetoothGatt﹕ onGetCharacteristic() - Device=CE:AD:09:F2:BB:DC UUID=randomUUID2
11-05 12:24:00.804 3683-3694/com.foo.ble D/BluetoothGatt﹕ onGetCharacteristic() - Device=CE:AD:09:F2:BB:DC UUID=randomUUID3
11-05 12:24:00.814 3683-3695/com.foo.ble D/BluetoothGatt﹕ onGetCharacteristic() - Device=CE:AD:09:F2:BB:DC UUID=randomUUID4
11-05 12:24:00.814 3683-3694/com.foo.ble D/BluetoothGatt﹕ onGetCharacteristic() - Device=CE:AD:09:F2:BB:DC UUID=randomUUID5
11-05 12:24:00.814 3683-3695/com.foo.ble D/BluetoothGatt﹕ onGetCharacteristic() - Device=CE:AD:09:F2:BB:DC UUID=randomUUID6
11-05 12:24:00.814 3683-3694/com.foo.ble D/BluetoothGatt﹕ onGetCharacteristic() - Device=CE:AD:09:F2:BB:DC UUID=randomUUID7
11-05 12:24:00.814 3683-3695/com.foo.ble D/BluetoothGatt﹕ onGetCharacteristic() - Device=CE:AD:09:F2:BB:DC UUID=something2
11-05 12:24:00.824 3683-3694/com.foo.ble D/BluetoothGatt﹕ onGetDescriptor() - Device=CE:AD:09:F2:BB:DC UUID=something3
11-05 12:24:00.824 3683-3695/com.foo.ble D/BluetoothGatt﹕ onSearchComplete() = Device=CE:AD:09:F2:BB:DC Status=0
11-05 12:24:00.824 3683-3695/com.foo.ble D/foo﹕ onServicesDiscovered
11-05 12:24:00.824 3683-3695/com.foo.ble D/BluetoothGatt﹕ setCharacteristicNotification() - uuid: something2 enable: true
11-05 12:24:00.834 3683-3695/com.foo.ble D/BluetoothGatt﹕ writeDescriptor() - uuid: something3
11-05 12:24:00.894 3683-3694/com.foo.ble D/BluetoothGatt﹕ onDescriptorWrite() - Device=CE:AD:09:F2:BB:DC UUID=something3
11-05 12:24:00.894 3683-3694/com.foo.ble D/foo﹕ onDescriptorWrite status: 0
11-05 12:24:00.894 3683-3694/com.foo.ble D/BluetoothGatt﹕ readCharacteristic() - uuid: something2
11-05 12:24:00.994 3683-3695/com.foo.ble D/BluetoothGatt﹕ onCharacteristicRead() - Device=CE:AD:09:F2:BB:DC UUID=something2 Status=0
11-05 12:24:00.994 3683-3695/com.foo.ble D/foo﹕ onCharacteristicRead status:0 payload: 0000000000050000000000000000005154010012任何帮助都将不胜感激！
回答 1
Stack Overflow用户
发布于 2014-11-13 16:54:21
我观察到一些通知或者没有处理某些电话/外围/环境组合，或者在同一连接会话中工作之后停止工作，没有明显的原因。所有调用都会返回成功，但通知不会通过。不管你是否解决了眼前的问题，你都应该考虑为你的特征值做一个阅读轮询，作为一个后备解决方案。
您的onServicesDiscovered()方法中的各种调用也应该通过对您正在调用的各个gatt方法的返回值的条件检查来关闭。
总之，有些事你可以试试：
- 尝试通过您的手机设置重置蓝牙堆栈，甚至重新启动整个手机。
- 测试其他设备。iOS有一些应用程序可以让您的iPhone充当外围设备。尝试连接到这样一个"sim设备“，看看通知在这种情况下是否有效。
- 试试不同的安卓手机。我观察到，Nexus 4在通知方面的问题最多，如果是这样的话。
最后，我将像技术支持一样询问计算机是否已插入:确保外围设备上的特征值确实在变化。
页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/26767634
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