Android 蓝牙低功耗配对 [英] Android Bluetooth Low Energy Pairing

问题描述

如何将 蓝牙低功耗 (BLE) 设备与 Android 配对以读取加密数据.

How to pair a Bluetooth Low Energy(BLE) device with Android to read encrypted data.

使用 Android BLE 页面中的信息，我能够发现设备，连接到它，发现服务并读取未加密的特征.

Using the information in the Android BLE page, I am able to discover the device, connect to it, discover services and read un-encrypted characteristics.

当我尝试读取加密特征(会导致 iOS 显示一个弹出窗口要求配对然后完成读取)时，我收到一个错误代码 5，它对应于 身份验证不足.

When I try to read an encrypted characteristic (one that will cause iOS to show a popup asking to pair and then complete the read) I am getting an error code 5, which corresponds to Insufficient Authentication.

我不确定如何使设备配对或如何提供身份验证信息以完成读取.

我通过尝试添加描述符来玩弄BluetoothGattCharacteristics，但这也不起作用.
任何帮助表示赞赏！

I toyed with BluetoothGattCharacteristics by trying to add descriptors, but that did not work either.
Any help is appreciated!

推荐答案

当您收到 GATT_INSUFFICIENT_AUTHENTICATION 错误时，系统会为您启动绑定过程.在下面的示例中，我尝试在血糖监测仪上启用通知和指示.首先，我启用了有关葡萄糖测量特性的通知，这可能会导致出现错误.

When you get the GATT_INSUFFICIENT_AUTHENTICATION error, the system starts the bonding process for you. In the example below I'm trying to enable notifications and indications on glucose monitor. First I'm enabling the notifications on Glucose Measurement characteristic which can cause the error to appear.

@Override
    public void onDescriptorWrite(BluetoothGatt gatt, BluetoothGattDescriptor descriptor, int status) {
        if (status == BluetoothGatt.GATT_SUCCESS) {
            if (GM_CHARACTERISTIC.equals(descriptor.getCharacteristic().getUuid())) {
                mCallbacks.onGlucoseMeasurementNotificationEnabled();

                if (mGlucoseMeasurementContextCharacteristic != null) {
                    enableGlucoseMeasurementContextNotification(gatt);
                } else {
                    enableRecordAccessControlPointIndication(gatt);
                }
            }

            if (GM_CONTEXT_CHARACTERISTIC.equals(descriptor.getCharacteristic().getUuid())) {
                mCallbacks.onGlucoseMeasurementContextNotificationEnabled();
                enableRecordAccessControlPointIndication(gatt);
            }

            if (RACP_CHARACTERISTIC.equals(descriptor.getCharacteristic().getUuid())) {
                mCallbacks.onRecordAccessControlPointIndicationsEnabled();
            }
        } else if (status == BluetoothGatt.GATT_INSUFFICIENT_AUTHENTICATION) {
            // this is where the tricky part comes

            if (gatt.getDevice().getBondState() == BluetoothDevice.BOND_NONE) {
                mCallbacks.onBondingRequired();

                // I'm starting the Broadcast Receiver that will listen for bonding process changes

                final IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_BOND_STATE_CHANGED);
                mContext.registerReceiver(mBondingBroadcastReceiver, filter);
            } else {
                // this situation happens when you try to connect for the second time to already bonded device
                // it should never happen, in my opinion
                Logger.e(TAG, "The phone is trying to read from paired device without encryption. Android Bug?");
                // I don't know what to do here
                // This error was found on Nexus 7 with KRT16S build of Andorid 4.4. It does not appear on Samsung S4 with Andorid 4.3.
            }
        } else {
            mCallbacks.onError(ERROR_WRITE_DESCRIPTOR, status);
        }
    };

mBondingBroadcastReceiver 在哪里:

Where the mBondingBroadcastReceiver is:

private BroadcastReceiver mBondingBroadcastReceiver = new BroadcastReceiver() {
    @Override
    public void onReceive(final Context context, final Intent intent) {
        final BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
        final int bondState = intent.getIntExtra(BluetoothDevice.EXTRA_BOND_STATE, -1);
        final int previousBondState = intent.getIntExtra(BluetoothDevice.EXTRA_PREVIOUS_BOND_STATE, -1);

        Logger.d(TAG, "Bond state changed for: " + device.getAddress() + " new state: " + bondState + " previous: " + previousBondState);

        // skip other devices
        if (!device.getAddress().equals(mBluetoothGatt.getDevice().getAddress()))
            return;

        if (bondState == BluetoothDevice.BOND_BONDED) {
            // Continue to do what you've started before
            enableGlucoseMeasurementNotification(mBluetoothGatt);

            mContext.unregisterReceiver(this);
            mCallbacks.onBonded();
        }
    }
};

记得在退出活动时注销广播接收器.它可能没有被接收器本身注销.

Remember to unregister the broadcast receiver when exiting the activity. It may have not been unregistered by the receicver itself.

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