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蓝牙开发、扫描、通知、发送指令

蓝牙开发、扫描、通知、发送指令

作者: maiduoduo | 来源:发表于2021-06-16 15:04 被阅读0次

    最近在做蓝牙相关的开发,虽然说 FastBleLib 这样的第三方蓝牙连接库非常方便,但是原生开发还是有必要了解一下的。

    首先说明

    • 1.不需要问硬件工程师UUID
    • 2.不需要写 UI
    • 3.本案例只有一个类文件
    • 4.没有写动态请求蓝牙权限相关的,自己测试过程中,手动开启所有权限即可。
    • 5.代码解释全部写在注释,和日志
    <uses-permission android:name="android.permission.BLUETOOTH"/>
    <!--此权限不开,可能搜不到蓝牙设备-->
    <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
    <uses-permission android:name="android.permission.BLUETOOTH_ADMIN"/>
    
    
    public class Main8Activity extends AppCompatActivity {
    
        //  蓝牙适配器对象,用于扫描蓝牙设备
        private BluetoothAdapter bluetoothAdapter;
    
        // GATT 通信,连接蓝牙,发送指令,以及接收蓝牙通知 ( 这里所谓的通知,就是蓝牙传过来的数据 )
        private BluetoothGatt bluetoothGatt;
    
        //  如果蓝牙没有开启
        private final static int REQUEST_ENABLE = 100;
    
        //  扫描到的蓝牙设备,因为 Set 不会重复,所以用这个数据结构
        private Set<BluetoothDevice> bluetoothDeviceSet;
    
        //  用户发送指令的操作
        private BluetoothGattCharacteristic writeBluetoothGattCharacteristic;
    
        //  用于开启通知的操作
        private BluetoothGattCharacteristic notificationBluetoothGattCharacteristic;
    
        //  服务和特征值
        private UUID write_UUID_service;
        private UUID write_UUID_chara;
    
        private UUID read_UUID_service;
        private UUID read_UUID_chara;
    
        private UUID notify_UUID_service;
        private UUID notify_UUID_chara;
    
        private UUID indicate_UUID_service;
        private UUID indicate_UUID_chara;
    
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main8);
    
            log("初始化蓝牙扫描 的 set 集合");
            bluetoothDeviceSet = new HashSet<>();
    
            log("开始获取蓝牙适配器");
            bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
    
            if(bluetoothAdapter != null){
    
                log("bluetoothAdapter 不为 null 当前设备支持蓝牙");
    
                if(!bluetoothAdapter.isEnabled()){
                    log("蓝牙未启动,正在使用 intent 启用蓝牙");
                    Intent intent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
                    startActivityForResult(intent,REQUEST_ENABLE);
                }else{
                    log("蓝牙已经启动,不需要使用 intent 启动蓝牙");
    
                    bluetoothAdapter.getBluetoothLeScanner().startScan(scanCallback);
                    log("开始扫描蓝牙设备");
                }
    
            }else{
                log("bluetoothAdapter 为 null 所以当前设备不支持蓝牙");
            }
    
        }
    
        @Override
        protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
            super.onActivityResult(requestCode, resultCode, data);
    
            if(requestCode == REQUEST_ENABLE){
                if(resultCode == RESULT_OK){
    
                    log("用户允许了开启蓝牙的请求");
    
                    log("开始扫描蓝牙设备");
                    bluetoothAdapter.getBluetoothLeScanner().startScan(scanCallback);
    
                }else if(resultCode == RESULT_CANCELED){
                    log("用户拒绝了开启蓝牙的请求");
                }
            }
    
        }
    
        //  蓝牙开始扫描回调
        private ScanCallback scanCallback = new ScanCallback() {
            @Override
            public void onScanResult(int callbackType, ScanResult result) {
                super.onScanResult(callbackType, result);
    
                //  bluetoothDevice 为扫描到的蓝牙设备
                BluetoothDevice bluetoothDevice = result.getDevice();
    
                //  添加扫描到的蓝牙设备到 set 集合
                boolean addResult = bluetoothDeviceSet.add(bluetoothDevice);
    
                //  如果 set 集合中未存在该蓝牙对象,则返回true
                if(addResult){
                    //log("onScanResult() 发现蓝牙设备" + bluetoothDevice.getName() + "," + bluetoothDevice.getAddress());
    
                    //log("目前已经发现" + bluetoothDeviceSet.size() + "个蓝牙设备");
    
                    //  如果当前添加的设备 蓝牙名称为 HTC_38908 MAC地址为  88:25:83:F1:04:58,则发起连接
                    //  懒得写 列表 UI 了,这里先直接指定好自己用来测试蓝牙的设备
                    if("HTC_38908".equals(bluetoothDevice.getName()) && "88:25:83:F1:04:58".equals(bluetoothDevice.getAddress()) ){
    
                        log("发现需要连接的设备");
    
                        log("因为蓝牙扫描比较消耗资源,所以连接前就关闭扫描");
    
                        //  bluetoothAdapter.stopScan(scanCallback);
                        bluetoothAdapter.cancelDiscovery();
    
                        log("开始 GATT 通信");
                        bluetoothGatt = bluetoothDevice.connectGatt(Main8Activity.this,true,bluetoothGattCallback);
    
                    }
                }
            }
    
            @Override
            public void onBatchScanResults(List<ScanResult> results) {
                super.onBatchScanResults(results);
            }
    
            @Override
            public void onScanFailed(int errorCode) {
                super.onScanFailed(errorCode);
            }
        };
    
        private BluetoothGattCallback bluetoothGattCallback = new BluetoothGattCallback() {
            @Override
            public void onPhyUpdate(BluetoothGatt gatt, int txPhy, int rxPhy, int status) {
                super.onPhyUpdate(gatt, txPhy, rxPhy, status);
            }
    
            @Override
            public void onPhyRead(BluetoothGatt gatt, int txPhy, int rxPhy, int status) {
                super.onPhyRead(gatt, txPhy, rxPhy, status);
            }
    
            @Override
            public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
                super.onConnectionStateChange(gatt, status, newState);
    
                if(BluetoothGatt.STATE_CONNECTED == newState){      //  蓝牙连接状态改变 为 -- 已连接
    
                    // 将会回调 本类中的 onServicesDiscovered() 这个方法
                    boolean result = gatt.discoverServices();
    
                    if(result){
                        log("蓝牙连接成功");
                    }else{
                        log("蓝牙连接失败");
                    }
    
                }else if(BluetoothGatt.STATE_DISCONNECTED == newState){     //  蓝牙连接状态改变为 -- 连接断开
    
                    log("断开连接");
    
                }
            }
    
            @Override
            public void onServicesDiscovered(BluetoothGatt gatt, int status) {
                super.onServicesDiscovered(gatt, status);
    
                //  这里初始化 各种 服务 和 描述 ,用来发送蓝牙指令的对象,还有接收蓝牙数据对象
                initServiceAndChara();
    
            }
    
            @Override
            public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
                super.onCharacteristicRead(gatt, characteristic, status);
    
                log("onCharacteristicRead");
            }
    
            @Override
            public void onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
                super.onCharacteristicWrite(gatt, characteristic, status);
    
                log("onCharacteristicWrite");
            }
    
            @Override
            public void onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
                super.onCharacteristicChanged(gatt, characteristic);
    
                //  这里将蓝牙传过来的数据转换为 16 进制格式的字符串,便于阅读
                byte[] bytes = characteristic.getValue();
    
                StringBuilder stringBuilder = new StringBuilder();
                for (byte b : bytes) {
                    stringBuilder.append(String.format("%02x", b));
                }
    
                log("蓝牙传回来的内容 ( 16进制 ) : " + stringBuilder.toString());
            }
    
            @Override
            public void onDescriptorRead(BluetoothGatt gatt, BluetoothGattDescriptor descriptor, int status) {
                super.onDescriptorRead(gatt, descriptor, status);
    
                log("onDescriptorRead");
            }
    
            @Override
            public void onDescriptorWrite(BluetoothGatt gatt, BluetoothGattDescriptor descriptor, int status) {
                super.onDescriptorWrite(gatt, descriptor, status);
    
                log("onDescriptorWrite");
            }
    
            @Override
            public void onReliableWriteCompleted(BluetoothGatt gatt, int status) {
                super.onReliableWriteCompleted(gatt, status);
    
                log("onReliableWriteCompleted");
            }
    
            @Override
            public void onReadRemoteRssi(BluetoothGatt gatt, int rssi, int status) {
                super.onReadRemoteRssi(gatt, rssi, status);
    
                log("onReadRemoteRssi");
            }
    
            @Override
            public void onMtuChanged(BluetoothGatt gatt, int mtu, int status) {
                super.onMtuChanged(gatt, mtu, status);
    
                log("onMtuChanged");
            }
        };
    
        private void initServiceAndChara(){
    
            List<BluetoothGattService> bluetoothGattServices= bluetoothGatt.getServices();
    
            for (BluetoothGattService bluetoothGattService:bluetoothGattServices){
    
                List<BluetoothGattCharacteristic> characteristics=bluetoothGattService.getCharacteristics();
    
                for (BluetoothGattCharacteristic characteristic:characteristics){
    
                    int charaProp = characteristic.getProperties();
    
                    if ((charaProp & BluetoothGattCharacteristic.PROPERTY_READ) > 0) {
                        read_UUID_chara=characteristic.getUuid();
                        read_UUID_service=bluetoothGattService.getUuid();
                        log("read_chara="+read_UUID_chara+"----read_service="+read_UUID_service);
                    }
    
                    if ((charaProp & BluetoothGattCharacteristic.PROPERTY_INDICATE) > 0) {
                        indicate_UUID_chara=characteristic.getUuid();
                        indicate_UUID_service=bluetoothGattService.getUuid();
                        log("indicate_chara="+indicate_UUID_chara+"----indicate_service="+indicate_UUID_service);
    
                    }
    
                    if ((charaProp & BluetoothGattCharacteristic.PROPERTY_WRITE) > 0) {
                        write_UUID_chara=characteristic.getUuid();
                        write_UUID_service=bluetoothGattService.getUuid();
                        log("write_chara="+write_UUID_chara+"----write_service="+write_UUID_service);
                    }
    
                    if ((charaProp & BluetoothGattCharacteristic.PROPERTY_WRITE_NO_RESPONSE) > 0) {
                        write_UUID_chara=characteristic.getUuid();
                        write_UUID_service=bluetoothGattService.getUuid();
                        log("write_chara="+write_UUID_chara+"----write_service="+write_UUID_service);
    
                        //  写入服务
                        BluetoothGattService service = bluetoothGatt.getService(write_UUID_service);
                        writeBluetoothGattCharacteristic = service.getCharacteristic(write_UUID_chara);
    
                        //  发送指令
                        sendBleData("*".getBytes());
    
                    }
    
                    if ((charaProp & BluetoothGattCharacteristic.PROPERTY_NOTIFY) > 0) {
                        notify_UUID_chara=characteristic.getUuid();
                        notify_UUID_service=bluetoothGattService.getUuid();
                        log("notify_chara="+notify_UUID_chara+"----notify_service="+notify_UUID_service);
    
                        //  初始化通知服务
                        BluetoothGattService service = bluetoothGatt.getService(notify_UUID_service);
                        notificationBluetoothGattCharacteristic = service.getCharacteristic(notify_UUID_chara);
    
                        //  开启通知
                        bluetoothGatt.setCharacteristicNotification(notificationBluetoothGattCharacteristic,true);
                    }
    
                }
            }
        }
    
        /**
         * 发送数据给蓝牙
         * @param data 数据byte[]
         * */
        private void sendBleData(byte[] data){
            writeBluetoothGattCharacteristic.setValue(data);
            bluetoothGatt.writeCharacteristic(writeBluetoothGattCharacteristic);
        }
    
        /**
         * 日志
         * @param log 日志内容
         * */
        private void log(String log){
            Log.i("蓝牙",log);
        }
    
    }
    
    

    以上,相信注释里面已经写的很清楚了。

    然后打开日志看就行了

    image

    参考

    蓝牙概览官方文档参考
    蓝牙参考文章

    作者:norkm
    链接:https://www.jianshu.com/p/cdb5bc8f9d85
    来源:简书
    著作权归作者所有。商业转载请联系作者获得授权,非商业转载请注明出处。

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