今天看了一下android 蓝牙BLE 记录一下
原创作者连接: http://blog.csdn.net/hellogv/
最近穿戴设备发展得很火,把相关技术也带旺了,其中一项是BLE(Bluetooth Low Energy)。BLE是蓝牙4.0的核心Profile,主打功能是快速搜索,快速连接,超低功耗保持连接和传输数据,弱点是数据传输速率低,由于BLE的低功耗特点,因此普遍用于穿戴设备。Android 4.3才开始支持BLE API,所以请各位客官把本文代码运行在蓝牙4.0和Android 4.3及其以上的系统,另外本文所用的BLE终端是一个蓝牙4.0的串口蓝牙模块。
PS:我的i9100刷了4.4系统后,竟然也能跟BLE蓝牙模块通信。
BLE分为三部分Service、Characteristic、Descriptor,这三部分都由UUID作为唯一标示符。一个蓝牙4.0的终端可以包含多个Service,一个Service可以包含多个Characteristic,一个Characteristic包含一个Value和多个Descriptor,一个Descriptor包含一个Value。一般来说,Characteristic是手机与BLE终端交换数据的关键,Characteristic有较多的跟权限相关的字段,例如PERMISSION和PROPERTY,而其中最常用的是PROPERTY,本文所用的BLE蓝牙模块竟然没有标准的Characteristic的PERMISSION。Characteristic的PROPERTY可以通过位运算符组合来设置读写属性,例如READ|WRITE、READ|WRITE_NO_RESPONSE|NOTIFY,因此读取PROPERTY后要分解成所用的组合(本文代码已含此分解方法)。
本文代码改自Android 4.3 Sample的BluetoothLeGatt,把冗余代码去掉,获取的BLE设备信息都通过Log,还有一些必要的读写蓝牙方法,应该算是简化到大家一看就可以懂了。本文代码可以到http://download.csdn.net/detail/hellogv/7228819下载。接下来贴出本文运行的结果,首先是连接BLE设备后,枚举出设备所有Service、Characteristic、Descriptor,并且手机会往Characteristic uuid=0000ffe1-0000-1000-8000-00805f9b34fb写入“send data->”字符串,BLE终端收到数据通过串口传到PC串口助手(见PC串口助手的截图):
04-21 18:28:25.465: E/DeviceScanActivity(12254): -->service type:PRIMARY
04-21 18:28:25.465: E/DeviceScanActivity(12254): -->includedServices size:0
04-21 18:28:25.465: E/DeviceScanActivity(12254): -->service uuid:00001800-0000-1000-8000-00805f9b34fb
04-21 18:28:25.465: E/DeviceScanActivity(12254): ---->char uuid:00002a00-0000-1000-8000-00805f9b34fb
04-21 18:28:25.465: E/DeviceScanActivity(12254): ---->char permission:UNKNOW
04-21 18:28:25.465: E/DeviceScanActivity(12254): ---->char property:READ
04-21 18:28:25.465: E/DeviceScanActivity(12254): ---->char uuid:00002a01-0000-1000-8000-00805f9b34fb
04-21 18:28:25.470: E/DeviceScanActivity(12254): ---->char permission:UNKNOW
04-21 18:28:25.470: E/DeviceScanActivity(12254): ---->char property:READ
04-21 18:28:25.470: E/DeviceScanActivity(12254): ---->char uuid:00002a02-0000-1000-8000-00805f9b34fb
04-21 18:28:25.470: E/DeviceScanActivity(12254): ---->char permission:UNKNOW
04-21 18:28:25.470: E/DeviceScanActivity(12254): ---->char property:READ|WRITE|
04-21 18:28:25.470: E/DeviceScanActivity(12254): ---->char uuid:00002a03-0000-1000-8000-00805f9b34fb
04-21 18:28:25.470: E/DeviceScanActivity(12254): ---->char permission:UNKNOW
04-21 18:28:25.475: E/DeviceScanActivity(12254): ---->char property:READ|WRITE|
04-21 18:28:25.475: E/DeviceScanActivity(12254): ---->char uuid:00002a04-0000-1000-8000-00805f9b34fb
04-21 18:28:25.475: E/DeviceScanActivity(12254): ---->char permission:UNKNOW
04-21 18:28:25.475: E/DeviceScanActivity(12254): ---->char property:READ
04-21 18:28:25.475: E/DeviceScanActivity(12254): -->service type:PRIMARY
04-21 18:28:25.475: E/DeviceScanActivity(12254): -->includedServices size:0
04-21 18:28:25.475: E/DeviceScanActivity(12254): -->service uuid:00001801-0000-1000-8000-00805f9b34fb
04-21 18:28:25.480: E/DeviceScanActivity(12254): ---->char uuid:00002a05-0000-1000-8000-00805f9b34fb
04-21 18:28:25.480: E/DeviceScanActivity(12254): ---->char permission:UNKNOW
04-21 18:28:25.480: E/DeviceScanActivity(12254): ---->char property:INDICATE
04-21 18:28:25.480: E/DeviceScanActivity(12254): -------->desc uuid:00002902-0000-1000-8000-00805f9b34fb
04-21 18:28:25.480: E/DeviceScanActivity(12254): -------->desc permission:UNKNOW
04-21 18:28:25.480: E/DeviceScanActivity(12254): -->service type:PRIMARY
04-21 18:28:25.480: E/DeviceScanActivity(12254): -->includedServices size:0
04-21 18:28:25.480: E/DeviceScanActivity(12254): -->service uuid:0000ffe0-0000-1000-8000-00805f9b34fb
04-21 18:28:25.480: E/DeviceScanActivity(12254): ---->char uuid:0000ffe1-0000-1000-8000-00805f9b34fb
04-21 18:28:25.480: E/DeviceScanActivity(12254): ---->char permission:UNKNOW
04-21 18:28:25.480: E/DeviceScanActivity(12254): ---->char property:READ|WRITE_NO_RESPONSE|NOTIFY|
04-21 18:28:25.490: E/DeviceScanActivity(12254): -------->desc uuid:00002902-0000-1000-8000-00805f9b34fb
04-21 18:28:25.490: E/DeviceScanActivity(12254): -------->desc permission:UNKNOW
04-21 18:28:25.490: E/DeviceScanActivity(12254): -------->desc uuid:00002901-0000-1000-8000-00805f9b34fb
04-21 18:28:25.490: E/DeviceScanActivity(12254): -------->desc permission:UNKNOW
04-21 18:28:26.025: E/DeviceScanActivity(12254): onCharRead BLE DEVICE read 0000ffe1-0000-1000-8000-00805f9b34fb -> 00
这里红字是由BluetoothGattCallback的onCharacteristicRead()回调而打出Log
以下Log是PC上的串口工具通过BLE模块发送过来,由BluetoothGattCallback的 onCharacteristicChanged()打出Log
04-21 18:30:18.260: E/DeviceScanActivity(12254): onCharWrite BLE DEVICE write 0000ffe1-0000-1000-8000-00805f9b34fb -> send data to phone
04-21 18:30:18.745: E/DeviceScanActivity(12254): onCharWrite BLE DEVICE write 0000ffe1-0000-1000-8000-00805f9b34fb -> send data to phone
04-21 18:30:19.085: E/DeviceScanActivity(12254): onCharWrite BLE DEVICE write 0000ffe1-0000-1000-8000-00805f9b34fb -> send data to phone
04-21 18:30:19.350: E/DeviceScanActivity(12254): onCharWrite BLE DEVICE write 0000ffe1-0000-1000-8000-00805f9b34fb -> send data to phone
04-21 18:30:19.605: E/DeviceScanActivity(12254): onCharWrite BLE DEVICE write 0000ffe1-0000-1000-8000-00805f9b34fb -> send data to phone
04-21 18:30:19.835: E/DeviceScanActivity(12254): onCharWrite BLE DEVICE write 0000ffe1-0000-1000-8000-00805f9b34fb -> send data to phone
04-21 18:30:20.055: E/DeviceScanActivity(12254): onCharWrite BLE DEVICE write 0000ffe1-0000-1000-8000-00805f9b34fb -> send data to phone
04-21 18:30:20.320: E/DeviceScanActivity(12254): onCharWrite BLE DEVICE write 0000ffe1-0000-1000-8000-00805f9b34fb -> send data to phone
04-21 18:30:20.510: E/DeviceScanActivity(12254): onCharWrite BLE DEVICE write 0000ffe1-0000-1000-8000-00805f9b34fb -> send data to phone
04-21 18:30:20.735: E/DeviceScanActivity(12254): onCharWrite BLE DEVICE write 0000ffe1-0000-1000-8000-00805f9b34fb -> send data to phone
04-21 18:30:21.000: E/DeviceScanActivity(12254): onCharWrite BLE DEVICE write 0000ffe1-0000-1000-8000-00805f9b34fb -> send data to phone
接下来贴出本文核心代码:
- public class DeviceScanActivity extends ListActivity {
- private final static String TAG = DeviceScanActivity.class.getSimpleName();
- private final static String UUID_KEY_DATA = "0000ffe1-0000-1000-8000-00805f9b34fb";
- private LeDeviceListAdapter mLeDeviceListAdapter;
- /**搜索BLE终端*/
- private BluetoothAdapter mBluetoothAdapter;
- /**读写BLE终端*/
- private BluetoothLeClass mBLE;
- private boolean mScanning;
- private Handler mHandler;
- // Stops scanning after 10 seconds.
- private static final long SCAN_PERIOD = 10000;
- @Override
- public void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- getActionBar().setTitle(R.string.title_devices);
- mHandler = new Handler();
- // Use this check to determine whether BLE is supported on the device. Then you can
- // selectively disable BLE-related features.
- if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH_LE)) {
- Toast.makeText(this, R.string.ble_not_supported, Toast.LENGTH_SHORT).show();
- finish();
- }
- // Initializes a Bluetooth adapter. For API level 18 and above, get a reference to
- // BluetoothAdapter through BluetoothManager.
- final BluetoothManager bluetoothManager =
- (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
- mBluetoothAdapter = bluetoothManager.getAdapter();
- // Checks if Bluetooth is supported on the device.
- if (mBluetoothAdapter == null) {
- Toast.makeText(this, R.string.error_bluetooth_not_supported, Toast.LENGTH_SHORT).show();
- finish();
- return;
- }
- //开启蓝牙
- mBluetoothAdapter.enable();
- mBLE = new BluetoothLeClass(this);
- if (!mBLE.initialize()) {
- Log.e(TAG, "Unable to initialize Bluetooth");
- finish();
- }
- //发现BLE终端的Service时回调
- mBLE.setOnServiceDiscoverListener(mOnServiceDiscover);
- //收到BLE终端数据交互的事件
- mBLE.setOnDataAvailableListener(mOnDataAvailable);
- }
- @Override
- protected void onResume() {
- super.onResume();
- // Initializes list view adapter.
- mLeDeviceListAdapter = new LeDeviceListAdapter(this);
- setListAdapter(mLeDeviceListAdapter);
- scanLeDevice(true);
- }
- @Override
- protected void onPause() {
- super.onPause();
- scanLeDevice(false);
- mLeDeviceListAdapter.clear();
- mBLE.disconnect();
- }
- @Override
- protected void onStop() {
- super.onStop();
- mBLE.close();
- }
- @Override
- protected void onListItemClick(ListView l, View v, int position, long id) {
- final BluetoothDevice device = mLeDeviceListAdapter.getDevice(position);
- if (device == null) return;
- if (mScanning) {
- mBluetoothAdapter.stopLeScan(mLeScanCallback);
- mScanning = false;
- }
- mBLE.connect(device.getAddress());
- }
- private void scanLeDevice(final boolean enable) {
- if (enable) {
- // Stops scanning after a pre-defined scan period.
- mHandler.postDelayed(new Runnable() {
- @Override
- public void run() {
- mScanning = false;
- mBluetoothAdapter.stopLeScan(mLeScanCallback);
- invalidateOptionsMenu();
- }
- }, SCAN_PERIOD);
- mScanning = true;
- mBluetoothAdapter.startLeScan(mLeScanCallback);
- } else {
- mScanning = false;
- mBluetoothAdapter.stopLeScan(mLeScanCallback);
- }
- invalidateOptionsMenu();
- }
- /**
- * 搜索到BLE终端服务的事件
- */
- private BluetoothLeClass.OnServiceDiscoverListener mOnServiceDiscover = new OnServiceDiscoverListener(){
- @Override
- public void onServiceDiscover(BluetoothGatt gatt) {
- displayGattServices(mBLE.getSupportedGattServices());
- }
- };
- /**
- * 收到BLE终端数据交互的事件
- */
- private BluetoothLeClass.OnDataAvailableListener mOnDataAvailable = new OnDataAvailableListener(){
- /**
- * BLE终端数据被读的事件
- */
- @Override
- public void onCharacteristicRead(BluetoothGatt gatt,
- BluetoothGattCharacteristic characteristic, int status) {
- if (status == BluetoothGatt.GATT_SUCCESS)
- Log.e(TAG,"onCharRead "+gatt.getDevice().getName()
- +" read "
- +characteristic.getUuid().toString()
- +" -> "
- +Utils.bytesToHexString(characteristic.getValue()));
- }
- /**
- * 收到BLE终端写入数据回调
- */
- @Override
- public void onCharacteristicWrite(BluetoothGatt gatt,
- BluetoothGattCharacteristic characteristic) {
- Log.e(TAG,"onCharWrite "+gatt.getDevice().getName()
- +" write "
- +characteristic.getUuid().toString()
- +" -> "
- +new String(characteristic.getValue()));
- }
- };
- // Device scan callback.
- 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() {
- mLeDeviceListAdapter.addDevice(device);
- mLeDeviceListAdapter.notifyDataSetChanged();
- }
- });
- }
- };
- private void displayGattServices(List<BluetoothGattService> gattServices) {
- if (gattServices == null) return;
- for (BluetoothGattService gattService : gattServices) {
- //-----Service的字段信息-----//
- int type = gattService.getType();
- Log.e(TAG,"-->service type:"+Utils.getServiceType(type));
- Log.e(TAG,"-->includedServices size:"+gattService.getIncludedServices().size());
- Log.e(TAG,"-->service uuid:"+gattService.getUuid());
- //-----Characteristics的字段信息-----//
- List<BluetoothGattCharacteristic> gattCharacteristics =gattService.getCharacteristics();
- for (final BluetoothGattCharacteristic gattCharacteristic: gattCharacteristics) {
- Log.e(TAG,"---->char uuid:"+gattCharacteristic.getUuid());
- int permission = gattCharacteristic.getPermissions();
- Log.e(TAG,"---->char permission:"+Utils.getCharPermission(permission));
- int property = gattCharacteristic.getProperties();
- Log.e(TAG,"---->char property:"+Utils.getCharPropertie(property));
- byte[] data = gattCharacteristic.getValue();
- if (data != null && data.length > 0) {
- Log.e(TAG,"---->char value:"+new String(data));
- }
- //UUID_KEY_DATA是可以跟蓝牙模块串口通信的Characteristic
- if(gattCharacteristic.getUuid().toString().equals(UUID_KEY_DATA)){
- //测试读取当前Characteristic数据,会触发mOnDataAvailable.onCharacteristicRead()
- mHandler.postDelayed(new Runnable() {
- @Override
- public void run() {
- mBLE.readCharacteristic(gattCharacteristic);
- }
- }, 500);
- //接受Characteristic被写的通知,收到蓝牙模块的数据后会触发mOnDataAvailable.onCharacteristicWrite()
- mBLE.setCharacteristicNotification(gattCharacteristic, true);
- //设置数据内容
- gattCharacteristic.setValue("send data->");
- //往蓝牙模块写入数据
- mBLE.writeCharacteristic(gattCharacteristic);
- }
- //-----Descriptors的字段信息-----//
- List<BluetoothGattDescriptor> gattDescriptors = gattCharacteristic.getDescriptors();
- for (BluetoothGattDescriptor gattDescriptor : gattDescriptors) {
- Log.e(TAG, "-------->desc uuid:" + gattDescriptor.getUuid());
- int descPermission = gattDescriptor.getPermissions();
- Log.e(TAG,"-------->desc permission:"+ Utils.getDescPermission(descPermission));
- byte[] desData = gattDescriptor.getValue();
- if (desData != null && desData.length > 0) {
- Log.e(TAG, "-------->desc value:"+ new String(desData));
- }
- }
- }
- }//
- }
- }