安卓低功耗蓝牙技术（BLE）入门指南

Android

2023-12-30 06:17:51

前言

在万物互联的时代，蓝牙低功耗技术（BLE）已成为物联网（IoT）不可或缺的一部分。在智能家居、医疗保健和工业自动化等领域，它都扮演着关键角色。Android作为最流行的移动操作系统，支持BLE，为开发人员提供了广泛的机会。

BLE 概述

BLE 是一种短距离无线通信技术，以低功耗和低成本著称。它基于经典蓝牙技术，但针对低功耗应用进行了优化，功耗仅为经典蓝牙的十分之一。BLE 提供了数据传输、数据读取、通知和指示等基本服务，使其非常适用于物联网应用。

Android BLE 编程

Android 从 4.3 版本开始支持 BLE，提供了全面的 API 和工具，帮助开发人员轻松构建 BLE 应用。

首先，你需要在 AndroidManifest.xml 文件中声明 BLE 权限：

<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />

然后，你需要初始化 BLE 适配器并扫描附近设备：

BluetoothAdapter bluetoothAdapter = BluetoothAdapter.getDefaultAdapter();
bluetoothAdapter.startLeScan(new BluetoothAdapter.LeScanCallback() {
    @Override
    public void onLeScan(BluetoothDevice device, int rssi, byte[] scanRecord) {
        // TODO: Process the BLE device
    }
});

当发现 BLE 设备后，你可以连接它并交换数据：

BluetoothDevice device = bluetoothAdapter.getRemoteDevice(address);
BluetoothGatt gatt = device.connectGatt(this, false, gattCallback);

最后，别忘了在完成任务后释放资源：

gatt.close();
bluetoothAdapter.stopLeScan(leScanCallback);

模拟 BLE 设备交互

如果没有实际的 BLE 设备，你也可以使用模拟器来模拟设备交互过程。Android Studio 提供了一个名为 BLE Scanner 的模拟器，它可以模拟 BLE 设备的行为。

要使用 BLE Scanner，你需要在 Android Studio 中创建一个新的 Android 项目，然后在项目中添加 BLE Scanner 库。在项目的 build.gradle 文件中添加以下依赖项：

implementation 'com.polidea.rxandroidble2:rxandroidble:2.2.3'

然后，你可以在项目中使用 BLE Scanner 库来模拟 BLE 设备：

RxBleClient rxBleClient = RxBleClient.create(this);
RxBleDevice bleDevice = rxBleClient.getBleDevice(address);

// Connect to the device
RxBleConnection rxBleConnection = bleDevice.establishConnection(false)
        .subscribe(
                connection -> {
                    // TODO: Connected to the device
                },
                throwable -> {
                    // TODO: Handle connection error
                }
        );

// Read data from the device
rxBleConnection.readCharacteristic(characteristicUuid)
        .subscribe(
                bytes -> {
                    // TODO: Process the data
                },
                throwable -> {
                    // TODO: Handle read error
                }
        );

// Write data to the device
rxBleConnection.writeCharacteristic(characteristicUuid, bytes)
        .subscribe(
                () -> {
                    // TODO: Data written successfully
                },
                throwable -> {
                    // TODO: Handle write error
                }
        );

// Disconnect from the device
rxBleConnection.disconnect()
        .subscribe(
                () -> {
                    // TODO: Disconnected from the device
                },
                throwable -> {
                    // TODO: Handle disconnect error
                }
        );