Question

现在我知道这个问题被问了十亿次。

我已经阅读了大多数内容（这个网站对我的问题没有帮助），我已经阅读了文档，并阅读了示例和教程。

我想做的是：

向hello世界发送BLE设备（已连接到arduino）

到目前为止我所做的：

使用内置设置与设备配对（未编程应用中的逻辑）

使用GATT服务器连接到设备。

但是，当我尝试编写特征时，相应的状态返回布尔值始终为false。这是最相关的代码：

private void setupServer(BluetoothAdapter bAdapter) {
    Log.d(TAG, "Started setting up server");

    BluetoothLeAdvertiser bAdvertiser = bAdapter.getBluetoothLeAdvertiser();
    if (bAdapter != null) {
        bGattServer = bManager.openGattServer(getApplicationContext(), new BluetoothGattServerCallback() {
            @Override
            public void onConnectionStateChange(BluetoothDevice device, int status, int newState) {
                super.onConnectionStateChange(device, status, newState);
            }
        });
        //Create a service using a random UUID
        //Create characteristics with WRITE property and write a value
        BluetoothGattService service = new BluetoothGattService(UUID.randomUUID(), BluetoothGattService.SERVICE_TYPE_PRIMARY);
        BluetoothGattCharacteristic bluetoothGattCharacteristic = new BluetoothGattCharacteristic(bUUID, BluetoothGattCharacteristic.PROPERTY_WRITE, BluetoothGattCharacteristic.PERMISSION_WRITE);
        Log.d(TAG, "Adding characteristic to service " + service.addCharacteristic(bluetoothGattCharacteristic));
        bluetoothGattCharacteristic.setValue("hello");
        Log.d(TAG, "Trying to write characteristic..., first value: " + bluetoothGattCharacteristic.getValue()[0]);
        if (bGatt != null) {
            boolean success = bGatt.writeCharacteristic(bluetoothGattCharacteristic);
            if (success) {
                Log.d(TAG, "Successfuly wrote characteristic to" + bUUID);
            } else {
                 //THIS ALWAYS EXECUTES??
                Log.e(TAG, "Failed to write to characteristic");
            }
        } else {
            Log.e(TAG, "BGATT IS NULL");
        }
        service.addCharacteristic(bluetoothGattCharacteristic);
        bGatt.setCharacteristicNotification(bluetoothGattCharacteristic, true);
        bGattServer.addService(service);
    }

这些是我的权限：

    <uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-feature android:name="android.hardware.bluetooth_le" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />

这是其余的相关代码

    private boolean scanBluetooth(final BluetoothAdapter bAdapter, final BluetoothDevice[] bDevice) {

    final BluetoothLeScanner bScanner = bAdapter.getBluetoothLeScanner();
    final boolean[] stopCallback = {false};
    Log.d(TAG,"Started scanning");
    bScanner.startScan(new ScanCallback() {
        @Override
        public void onScanResult(int callbackType, ScanResult result) {
            super.onScanResult(callbackType, result);
            bDevice[0] = result.getDevice();
            if (bDevice[0] == null || stopCallback[0]) {
                Toast.makeText(getApplicationContext(), "Didn't find a device", Toast.LENGTH_LONG);

            } else {
                stopCallback[0] = true;
                System.out.println("DEVICE" + bDevice[0]);
                bGatt = bDevice[0].connectGatt(getApplicationContext(), true, new BluetoothGattCallback() {
                    @Override
                    public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
                        super.onConnectionStateChange(gatt, status, newState);
                        if(status == BluetoothGatt.GATT_SUCCESS){
                            Log.d(TAG, "Successful GATT " + newState);
                            setupServer(bAdapter);
                            return;
                        }
                        if(status == BluetoothGatt.GATT_FAILURE){
                            Log.e(TAG,"Bigg error boi");
                            System.exit(1);
                        }
                        else{
                            Log.w(TAG,"Oh no, gatt failed " + status + " retrying");
                            return;
                        }

                    }
                    @Override
                    public void onCharacteristicWrite(BluetoothGatt gatt,
                                                      BluetoothGattCharacteristic characteristic, int status) {
                        Log.d(TAG, "Characteristic written" + status);
                    }

                }, BluetoothDevice.TRANSPORT_LE);
                Log.d(TAG, "Bgatt value:" + bGatt);


            }
        }
    });
    if(bGatt==null){
        Log.w(TAG, "BGATT IS NULL WHILE SCANNING");
    }
    Log.d(TAG, "Finished scanning...");
    return true;
}

我已经使用BLEScanner应用程序获得了bUUID，其中显示了用于读写的UUID。我的应用程序的目标是反映该应用程序的功能，但是我开始失去理智。我什至无法发送一个简单的hello世界。

Android Studio输出：

018-12-01 23:58:56.214 25024-25136/com.iopt.davidv7.iopt W/DBG: Oh no, gatt failed 22 retrying
2018-12-01 23:58:56.675 25024-25136/com.iopt.davidv7.iopt D/DBG: Successful GATT 2
2018-12-01 23:58:56.675 25024-25136/com.iopt.davidv7.iopt D/DBG: Started setting up server
2018-12-01 23:58:56.692 25024-25136/com.iopt.davidv7.iopt D/DBG: Adding characteristic to service true
2018-12-01 23:58:56.693 25024-25136/com.iopt.davidv7.iopt D/DBG: Trying to write characteristic..., first value: 104
2018-12-01 23:58:56.693 25024-25136/com.iopt.davidv7.iopt E/DBG: Failed to write to characteristic

客户端是一个简单的HM-10蓝牙模块，我现在想使用ARDUINO IDE在串行监视器上镜像我在应用程序中发送的内容。

我希望我能给您所有背景信息，因为我失去了希望。我不是手动检查权限，因为我已经使用系统对话框设置了权限，但是只有“位置”要启用吗？这可能是我问题的根源吗？用checkSelfPermission检查蓝牙，但是蓝牙管理员返回true，所以我不认为是这样：

        if (ContextCompat.checkSelfPermission(getApplicationContext(), Manifest.permission.BLUETOOTH_ADMIN)
            != PackageManager.PERMISSION_GRANTED) {
        Log.e(TAG,"No permission for bluetooth");
        // Permission is not granted
    }
    else{
        Log.d(TAG,"Bluetooth permission granted");
    }

Answer 1

似乎我的问题是创建新服务，而不是使用发现服务然后解析发现的服务。因此，您的做法是： 1.触发discoverServices（），依次触发回调中的onServicesDiscovered（） 2.之后，从发现的服务中创建服务，并从服务中创建特征。因为我当前的硬件仅支持一个特性，所以我只能取出第一个（也是唯一一个）服务。 3.使用setValue将值设置为服务 4.为服务添加特征

我不会深入解释readData代码的作用，但是它可能会帮助某人弄清楚如何触发通知并从中读取数据。

private boolean scanBluetooth(final BluetoothAdapter bAdapter, final BluetoothDevice[] bDevice) {

    final BluetoothLeScanner bScanner = bAdapter.getBluetoothLeScanner();
    final boolean[] stopCallback = {false};
    Log.d(TAG,"Started scanning");
    bScanner.startScan(new ScanCallback() {
        @Override
        public void onScanResult(int callbackType, ScanResult result) {
            super.onScanResult(callbackType, result);
            bDevice[0] = result.getDevice();
            if (bDevice[0] == null || stopCallback[0]) {
                Toast.makeText(getApplicationContext(), "Didn't find a device", Toast.LENGTH_LONG);

            } else {
                stopCallback[0] = true;
                System.out.println("DEVICE" + bDevice[0]);
                bGatt = bDevice[0].connectGatt(getApplicationContext(), true, new BluetoothGattCallback() {
                    @Override
                    public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
                        super.onConnectionStateChange(gatt, status, newState);
                        if(status == BluetoothGatt.GATT_SUCCESS){
                            Log.d(TAG, "Successful GATT " + newState);
                            //Simply triggers a discoverService method, which in return triggers onServiceDiscovered, which writes sample data into the characteristic
                            setupClient(bAdapter);
                            return;

                        }
                        if(status == BluetoothGatt.GATT_FAILURE){
                            Log.e(TAG,"Bigg error boi");
                            System.exit(1);
                        }
                        else{
                            Log.w(TAG,"Oh no, gatt failed " + status + " retrying");
                            return;
                        }

                    }
                    @Override
                    //Triggered after we write data in a characteristic
                    public void onCharacteristicWrite(BluetoothGatt gatt,
                                                      BluetoothGattCharacteristic characteristic, int status) {
                        Log.d(TAG, "Characteristic written" + status);
                    }
                    //Triggered when someone(the remote device if everything is set up correctly) changes a characteristic!

                    public void onCharacteristicChanged(BluetoothGatt gatt,
                                                        BluetoothGattCharacteristic characteristic) {
                        Log.w(TAG,"Characteristic changed");
                        try {
                            Log.d(TAG,"Change characteristic" + new String(characteristic.getValue(),"UTF-8"));
                        } catch (UnsupportedEncodingException e) {
                            e.printStackTrace();
                        }
                    }
                    public void onServicesDiscovered(BluetoothGatt gatt, int status) {
                        Log.d(TAG,"Size of discovered" + gatt.getServices().size());
                        getData(gatt);
                        writeCharacteristic(gatt);
                        Log.d(TAG,"Services discovered");
                    }


                }, BluetoothDevice.TRANSPORT_LE);
                Log.d(TAG, "Bgatt value:" + bGatt);


            }
        }
    });
    if(bGatt==null){
        Log.w(TAG, "BGATT IS NULL WHILE SCANNING");
    }
    Log.d(TAG, "Finished scanning...");
    return true;
}
//Doesn't do much, starts discovering services, which triggers onServicesDiscovered
private void setupClient(BluetoothAdapter bAdapter) {
    Log.d(TAG, "Started setting up server");

    if (bAdapter != null) {
        Log.d(TAG, "SERVICE DISCOVERED" + bGatt.discoverServices());

    }
}
//Write characteristic into the discovered service
//There is only one characteristic, so we can just take the first index
private void writeCharacteristic(BluetoothGatt gatt){
                                BluetoothGattService bService = gatt.getService(bUUID);
                        BluetoothGattCharacteristic bChars = bService.getCharacteristics().get(0);

                        if(bChars != null){
                            bChars.setValue("Hello");
                            bService.addCharacteristic(bChars);
                            boolean success = gatt.writeCharacteristic(bChars);
                            if(success){
                                Log.d(TAG, "Write characteristic successful");
                            }
                            else{
                                Log.e(TAG, "Write characteristic failed");
                            }
                        }
                        else{
                            Log.e(TAG,"Characteristic not found");
                        }
}
//Set up notifications for the discovered service!
    private void getData(BluetoothGatt gatt){

        BluetoothGattService bService = gatt.getService(bUUID);
        BluetoothGattCharacteristic bChars = bService.getCharacteristics().get(0);
        gatt.setCharacteristicNotification(bChars,true);
    }

写特征始终为假

1 个答案: