《Android BLE 开发》--初学者

Rice加饭

发布于 2022-05-09 20:58:15

8430

发布于 2022-05-09 20:58:15

本作者是一位安卓初学者，之前学过JAVA，安卓只学过三天。《BLE Tool》也是我一个安卓项目，因为作者学习安卓加开发只用了10天时间，目前只是把所有接口打通了，只提供如何怎么实现。有不对的地方，大家多指点。开发之前，最好了解一下BLE的通信原理。最终实现的界面：

1.开启权限

在AndroidManifest.xml中添加一下代码：

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

2.初始化BLE

第一步：判断设备是否支持BLE功能

第二步：通过蓝牙管理器获取蓝牙适配器

第三步：判断设备是否打开蓝牙

在MainActivity.java中添加以下代码：

public boolean initialize() {
        if(!getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH_LE)){
            Log.e(TAG, "No support BLE.");
            finish();
        }
        if (mBluetoothManager == null) {
            mBluetoothManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
            if (mBluetoothManager == null) {
                Log.e(TAG, "Unable to initialize BluetoothManager.");
                return false;
            }
        }
        mBluetoothAdapter = mBluetoothManager.getAdapter();
        if (mBluetoothAdapter == null) {
            Log.e(TAG, "Unable to obtain a BluetoothAdapter.");
            return false;
        }
        if(!mBluetoothAdapter.isEnabled()) {
            Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
            startActivityForResult(enableBtIntent, 1);
        }
        return true;
    }

3.扫描设备实现

本作者时间扫描设备添加到Spanner控件中，在MainActivity.java中添加以下代码：

第一步：编写扫描函数

第二步：添加扫描回调函数

private void scanLeDevice(final boolean enable) {
 if(enable) {
 mHandler.postDelayed(new Runnable() {
 @Override
 public void run() {
 mScanning = false;
 mBluetoothAdapter.stopLeScan(mLeScanCallback);
 }
 },SCAN_PERIOD);
 mScanning = true;
 mBluetoothAdapter.startLeScan(mLeScanCallback);
 }
}
private BluetoothAdapter.LeScanCallback mLeScanCallback = new BluetoothAdapter.LeScanCallback() {
 @Override
 public void onLeScan(final BluetoothDevice device, int rssi, byte[] scanRecord) {
 runOnUiThread(new Runnable() {
 @Override
 public void run() {
 if (device.getName() != null) {
 if (!mSearchBluetoothList.contains(device)) {
 mSearchBluetoothList.add(device);
 mBLENameList.add(device.getName());
 }
 }
 }
 });
 }
};

4.将扫描到的设备添加到Spanner控件中

在MainActivity.java中添加以下代码：

private void setBLEName2Spanner(){
 BLE_List_Spinner.setOnItemSelectedListener(this);
 mBLENameList.add("<BLE List>");
 ListAdapter = new ArrayAdapter<String>(this,android.R.layout.simple_spinner_item,mBLENameList);
 ListAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
 BLE_List_Spinner.setAdapter(ListAdapter);
}

5.连接设备

在Spanner控件中选择要连接的设备，Spanner的选择事件实现，在MainActivity.java中添加以下代码：

@Override
public void onItemSelected(AdapterView<?> parent,View view,int position,long id)
{
 disconnect();
 close();
 String item = parent.getSelectedItem().toString();
 if(item != "<BLE List>") {
 for(BluetoothDevice device : mSearchBluetoothList) {
 if(device.getName().equals(item)) {
 if(connect(device.getAddress()) == true) {
 BLE_Connect_Button.setText("BLE DISCONNECT");
 }
 }
 }
 }
}
public void onNothingSelected(AdapterView<?> arg0)
{
}

连接函数的实现，在MainActivity.java中添加以下代码：

public boolean connect(final String address) {
 if (mBluetoothAdapter == null || address == null) {
 Log.w(TAG, "BluetoothAdapter not initialized or unspecified address.");
 return false;
 }
 if (mBluetoothDeviceAddress != null && address.equals(mBluetoothDeviceAddress)
 && mBluetoothGatt != null) {
 Log.d(TAG, "Trying to use an existing mBluetoothGatt for connection.");
 if (mBluetoothGatt.connect()) {
 mConnectionState = STATE_CONNECTING;
 return true;
 } else {
 return false;
 }
 }
 final BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address);
 if (device == null) {
 Log.w(TAG, "Device not found.  Unable to connect.");
 return false;
 }
 mBluetoothGatt = device.connectGatt(this, false, mGattCallback);
 Log.d(TAG, "Trying to create a new connection.");
 mBluetoothDeviceAddress = address;
 mConnectionState = STATE_CONNECTING;
 System.out.println("device.getBondState==" + device.getBondState());
 return true;
}

6.断开连接

断开连接函数的实现，在MainActivity.java中添加以下代码：

public void disconnect() {
 if (mBluetoothAdapter == null || mBluetoothGatt == null) {
 Log.w(TAG, "BluetoothAdapter not initialized");
 return;
 }
 mBluetoothGatt.disconnect();
}

7.读特征实现

读特征函数的实现，在MainActivity.java中添加以下代码：

public void readCharacteristic(BluetoothGattCharacteristic characteristic) {
 if (mBluetoothAdapter == null || mBluetoothGatt == null) {
 Log.w(TAG, "BluetoothAdapter not initialized");
 return;
 }
 mBluetoothGatt.readCharacteristic(characteristic);
}

8.写特征实现

写特征函数的实现，在MainActivity.java中添加以下代码：

public boolean writeCharacteristic(BluetoothGattCharacteristic characteristic) {
 if (mBluetoothAdapter == null || mBluetoothGatt == null) {
 Log.w(TAG, "BluetoothAdapter not initialized");
 return false;
 }
 return mBluetoothGatt.writeCharacteristic(characteristic);
}

9.设置特征的通知的实现

特征通知函数的实现，在MainActivity.java中添加以下代码：

public void setCharacteristicNotification(BluetoothGattCharacteristic characteristic,
   boolean enabled) {
 if (mBluetoothAdapter == null || mBluetoothGatt == null) {
 Log.w(TAG, "BluetoothAdapter not initialized");
 return;
 }
 boolean isEnableNotification = mBluetoothGatt.setCharacteristicNotification(characteristic,enabled);
 if(isEnableNotification) {
 List<BluetoothGattDescriptor>descriptorList = characteristic.getDescriptors();
 if(descriptorList != null && descriptorList.size() >0) {
 for(BluetoothGattDescriptor descriptor : descriptorList) {
 descriptor.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE);
 mBluetoothGatt.writeDescriptor(descriptor);
 }
 }
 }
}

10.关闭BLE实现

关闭函数的实现，在MainActivity.java中添加以下代码：

public void close() {
 if (mBluetoothGatt == null) {
 return;
 }
 mBluetoothGatt.close();
 mBluetoothGatt = null;
}

11.功能的回调函数的实现

从第5点到第10的最终事项都需要调用回调函数，回调函数的实现，在MainActivity.java中添加以下代码：

private final BluetoothGattCallback mGattCallback = new BluetoothGattCallback() {
 @Override
 public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
 String intentAction;
 if (newState == BluetoothProfile.STATE_CONNECTED) {
 intentAction = ACTION_GATT_CONNECTED;
 mConnectionState = STATE_CONNECTED;
 gatt.discoverServices();
 broadcastUpdate(intentAction);
 } else if (newState == BluetoothProfile.STATE_DISCONNECTED) {
 intentAction = ACTION_GATT_DISCONNECTED;
 mConnectionState = STATE_DISCONNECTED;
 Log.i(TAG, "Disconnected from GATT server.");
 broadcastUpdate(intentAction);
 }
 }
 @Override
 public void onServicesDiscovered(BluetoothGatt gatt, int status) {
 if (status == BluetoothGatt.GATT_SUCCESS) {
 supportedGattServices = gatt.getServices();
 for (BluetoothGattService gattService : supportedGattServices) {
 if(gattService.getUuid().toString().equals("0000fe8f-0000-1000-8000-00805f9b34fb")) {
 gattCharacteristics = gattService.getCharacteristics();
 for(BluetoothGattCharacteristic gattCharacteristic : gattCharacteristics) {
 if(gattCharacteristic.getUuid().toString().equals("44fa50b2-d0a3-472e-a939-d80cf17638bb")) {
 Log.e("BLE Tool", "Log Link Success");
    //Log.e("BLE Tool", gattCharacteristic.getUuid().toString());
 }
 }
 }
 }
 broadcastUpdate(ACTION_GATT_SERVICES_DISCOVERED);
 }
 else {
 Log.w(TAG, "onServicesDiscovered received: " + status);
 }
 }
 @Override
 public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
 if (status == BluetoothGatt.GATT_SUCCESS) {
 broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic);
 Log.e("BLE Tool", "Characteristic Read");
 }
 }
 @Override
 public void onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
 broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic);
 Log.e("BLE Tool", "Characteristic Notify");
 }
 @Override
 public void onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
 super.onCharacteristicWrite(gatt, characteristic, status);
 if (status == BluetoothGatt.GATT_SUCCESS) {
 broadcastUpdate(ACTION_GATT_WRITE);
 Log.e("BLE Tool", "Characteristic Write");
 }
 }
};
private void broadcastUpdate(final String action){
 final Intent intent = new Intent(action);
 sendBroadcast(intent);
}
private void broadcastUpdate(final String action, final BluetoothGattCharacteristic characteristic) {
 final Intent intent = new Intent(action);
 final byte[] data = characteristic.getValue();
 for(int i =0; i<data.length; i++) {
 System.out.println("data..."+data[i]);
 }
 sendBroadcast(intent);
}

说道这里基本把所有要实现的功能函数都说完了。

本文参与腾讯云自媒体同步曝光计划，分享自微信公众号。

原始发表：2019-01-07，如有侵权请联系 cloudcommunity@tencent.com 删除

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