Android BLE 蓝牙编程(三)
上节我们已经可以连接上蓝牙设备了。
本节我们就要获取手环的电池电量和计步啦。
在介绍这个之前我们需要先了解下什么是 服务 什么是 UUID
我们记得上节中我们item监听事件的回调的返回值是BluetoothGatt 类型的,还记得么?嘿嘿。
返回的bluetoothgatt中包含一个或多个BluetoothGattService(服务)
每个service包含一个或多个characteristic(特征值)
每个特征值包含一个value 和多个 descriptor(注意看啊!是一个value)
这些对于本项目来说某个特征值的value中就包含了记录的步数。(很遗憾我折腾了很久也没找到电池电量,不得不舍弃展示电池电量的想法)
先熟悉下下面的图片吧~~
(百度脑图)
在了解下UUID 上图中每个蓝牙设备都有自己的MAC 地址有了这个地址 我们就可以连接这个设备。
连接上设备后会的到设备的服务就是上图中的Gattservice 这每个service都有个固定的UUID以标识区分
每个service又包含多个的characteristic 这些特征值也有唯一的UUID 这些UUID就是我们编程需要的,
获取到characteristic对应的UUID就意味着获取到该characteristic提供的功能或者数据。
特征值对应的UUID所实现的功能是由硬件工程师决定的。
因为小米手环的硬件工程师我们没有联系方式,况且人家也肯定不会告诉我所有功能对应的UUID
因此我们只好自己对应数值来找了。
简单说 上图的每个characteristic 都对应一个UUID 这些UUID对应了设备的不同功能
手环为例:
控制手环震动的 UUID :00002a06-0000-1000-8000-00805f9b34fb 手机向该 UUID 写入 0x01 或者 0x02 时手环都会震动,01强度弱于 02
计步的 UUID :0000ff06-0000-1000-8000-00805f9b34fb 读取该UUID下的value数组 第0 个数据就是 步数
首先我们来获取下计步数吧
经过一番折腾我终于找到了小米手环对应步数的 UUID :0000ff06-0000-1000-8000-00805f9b34fb
gattcallback 回调方法中找到 onServicesDiscovered
添加如下代码:
@Override public void onServicesDiscovered(BluetoothGatt gatt, int status) { super.onServicesDiscovered(gatt, status); //寻找到服务时 if (status == bluetoothGatt.GATT_SUCCESS) { final List<BluetoothGattService> services = bluetoothGatt.getServices(); runOnUiThread(new Runnable() { @Override public void run() { //List<String> serlist = new ArrayList<>(); for (final BluetoothGattService bluetoothGattService : services) { bluetoothGattServices = bluetoothGattService; Log.i(TAG, "onServicesDiscovered: " + bluetoothGattService.getUuid()); List<BluetoothGattCharacteristic> charc = bluetoothGattService.getCharacteristics(); for (BluetoothGattCharacteristic charac : charc) { Log.i(TAG, "run: " + charac.getUuid()); //找到透传特征值 // 00002a06-0000-1000-8000-00805f9b34fb 小米手环震动特征值 0x01震动 0x02强震 if (charac.getUuid().toString().equals("00002a06-0000-1000-8000-00805f9b34fb")) { //设备 震动特征值 characteristic_zd = charac; } else if (charac.getUuid().toString().equals("0000ff06-0000-1000-8000-00805f9b34fb")) { //设备 步数 characteristic_jb = charac; bluetoothGatt.readCharacteristic(characteristic_jb); Log.i(TAG, "run: 正在尝试读取步数"); } else if (charac.getUuid().toString().equals("")) { //设备 电量特征值 } } serviceslist.add(bluetoothGattService.getUuid().toString()); } } }); } }
注释写的很清楚
我用 characteristic_zd 记住震动的特征值
用 characteristic_jb 记住计步的
记住计步特征值后使用 bluetoothGatt 提供的read方法并传人相应特征值。该方法为异步方法他的返回内容会由
回调中的 onCharacteristicRead 方法接收到
找到该方法添加如下代码:
if (status == bluetoothGatt.GATT_SUCCESS) { final int sum = characteristic.getValue()[0]; runOnUiThread(new Runnable() { @Override public void run() { jibu.setText("走了" + sum + "步"); } }); Log.e(TAG, "onCharacteristicRead: " + characteristic.getValue()[0]); }
方法的参数中status表示状态,为 bluetoothGatt.GATT_SUCCESS 时表示成功获取返回
因为在异步方法中,想要操作UI线程,于是就用了 runOnUiThread 方法。显示出来步数即可。
好了下面贴出完整主Activity代码:
MainActivity.java:
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
package com.wbnq.shouhuan; import android.bluetooth.BluetoothAdapter; import android.bluetooth.BluetoothDevice; import android.bluetooth.BluetoothGatt; import android.bluetooth.BluetoothGattCallback; import android.bluetooth.BluetoothGattCharacteristic; import android.bluetooth.BluetoothGattDescriptor; import android.bluetooth.BluetoothGattService; import android.bluetooth.BluetoothManager; import android.content.Intent; import android.support.v7.app.AppCompatActivity; import android.os.Bundle; import android.util.Log; import android.view.View; import android.widget.AdapterView; import android.widget.ArrayAdapter; import android.widget.Button; import android.widget.ListView; import android.widget.TextView; import android.widget.Toast; import java.util.ArrayList; import java.util.List; import java.util.UUID; public class MainActivity extends AppCompatActivity implements View.OnClickListener { private Button saomiao, duanzhen, changzhen, buting, tingxia; private TextView jibu, dianliang, lianjiezhuangtai; private ListView list; public static String TAG = "shouhuan-MainActivity"; BluetoothAdapter bluetoothAdapter; BluetoothGatt bluetoothGatt; List<BluetoothDevice> deviceList = new ArrayList<>(); List<String> serviceslist = new ArrayList<String>(); BluetoothDevice bluetoothDevice; BluetoothGattService bluetoothGattServices; BluetoothGattCharacteristic characteristic_zd, characteristic_jb; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); initView(); //蓝牙管理,这是系统服务可以通过getSystemService(BLUETOOTH_SERVICE)的方法获取实例 BluetoothManager bluetoothManager = (BluetoothManager) getSystemService(BLUETOOTH_SERVICE); //通过蓝牙管理实例获取适配器,然后通过扫描方法(scan)获取设备(device) bluetoothAdapter = bluetoothManager.getAdapter(); } private void initView() { saomiao = (Button) findViewById(R.id.saomiao); duanzhen = (Button) findViewById(R.id.zhendong); changzhen = (Button) findViewById(R.id.changzhen); buting = (Button) findViewById(R.id.buting); tingxia = (Button) findViewById(R.id.tingxia); list = (ListView) findViewById(R.id.list); jibu = (TextView) findViewById(R.id.jibu); dianliang = (TextView) findViewById(R.id.dianliang); lianjiezhuangtai = (TextView) findViewById(R.id.lianjiezhuangtai); saomiao.setOnClickListener(this); duanzhen.setOnClickListener(this); changzhen.setOnClickListener(this); buting.setOnClickListener(this); tingxia.setOnClickListener(this); //item 监听事件 list.setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) { bluetoothDevice = deviceList.get(i); //连接设备的方法,返回值为bluetoothgatt类型 bluetoothGatt = bluetoothDevice.connectGatt(MainActivity.this, false, gattcallback); lianjiezhuangtai.setText("连接" + bluetoothDevice.getName() + "中..."); } }); } @Override public void onClick(View view) { switch (view.getId()) { case R.id.saomiao: //开始扫描前开启蓝牙 Intent turn_on = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE); startActivityForResult(turn_on, 0); Toast.makeText(MainActivity.this, "蓝牙已经开启", Toast.LENGTH_SHORT).show(); Thread scanThread = new Thread(new Runnable() { @Override public void run() { Log.i("TAG", "run: saomiao ..."); saomiao(); } }); scanThread.start(); lianjiezhuangtai.setText("正在扫描"); break; case R.id.zhendong: break; case R.id.changzhen: break; case R.id.buting: break; case R.id.tingxia: break; case R.id.list: break; } } public void saomiao() { deviceList.clear(); bluetoothAdapter.startLeScan(callback); } //扫描回调 public BluetoothAdapter.LeScanCallback callback = new BluetoothAdapter.LeScanCallback() { @Override public void onLeScan(final BluetoothDevice bluetoothDevice, int i, byte[] bytes) { Log.i("TAG", "onLeScan: " + bluetoothDevice.getName() + "/t" + bluetoothDevice.getAddress() + "/t" + bluetoothDevice.getBondState()); //重复过滤方法,列表中包含不该设备才加入列表中,并刷新列表 if (!deviceList.contains(bluetoothDevice)) { //将设备加入列表数据中 deviceList.add(bluetoothDevice); list.setAdapter(new MyAdapter(MainActivity.this, deviceList)); } } }; private BluetoothGattCallback gattcallback = new BluetoothGattCallback() { @Override public void onConnectionStateChange(BluetoothGatt gatt, int status, final int newState) { super.onConnectionStateChange(gatt, status, newState); runOnUiThread(new Runnable() { @Override public void run() { String status; switch (newState) { //已经连接 case BluetoothGatt.STATE_CONNECTED: lianjiezhuangtai.setText("已连接"); bluetoothAdapter.stopLeScan(callback); //该方法用于获取设备的服务,寻找服务 bluetoothGatt.discoverServices(); break; //正在连接 case BluetoothGatt.STATE_CONNECTING: lianjiezhuangtai.setText("正在连接"); break; //连接断开 case BluetoothGatt.STATE_DISCONNECTED: lianjiezhuangtai.setText("已断开"); break; //正在断开 case BluetoothGatt.STATE_DISCONNECTING: lianjiezhuangtai.setText("断开中"); break; } //pd.dismiss(); } }); } @Override public void onServicesDiscovered(BluetoothGatt gatt, int status) { super.onServicesDiscovered(gatt, status); //寻找到服务时 if (status == bluetoothGatt.GATT_SUCCESS) { final List<BluetoothGattService> services = bluetoothGatt.getServices(); runOnUiThread(new Runnable() { @Override public void run() { //List<String> serlist = new ArrayList<>(); for (final BluetoothGattService bluetoothGattService : services) { bluetoothGattServices = bluetoothGattService; Log.i(TAG, "onServicesDiscovered: " + bluetoothGattService.getUuid()); List<BluetoothGattCharacteristic> charc = bluetoothGattService.getCharacteristics(); for (BluetoothGattCharacteristic charac : charc) { Log.i(TAG, "run: " + charac.getUuid()); //找到透传特征值 // 00002a06-0000-1000-8000-00805f9b34fb 小米手环震动特征值 0x01震动 0x02强震 if (charac.getUuid().toString().equals("00002a06-0000-1000-8000-00805f9b34fb")) { //设备 震动特征值 characteristic_zd = charac; } else if (charac.getUuid().toString().equals("0000ff06-0000-1000-8000-00805f9b34fb")) { //设备 步数 characteristic_jb = charac; bluetoothGatt.readCharacteristic(characteristic_jb); Log.i(TAG, "run: 正在尝试读取步数"); } else if (charac.getUuid().toString().equals("")) { //设备 电量特征值 } } serviceslist.add(bluetoothGattService.getUuid().toString()); } // ArrayAdapter<String> adapter = new ArrayAdapter<String>( // MainActivity.this, android.R.layout.simple_expandable_list_item_1, serviceslist); //list.setAdapter(adapter); } }); } } @Override public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) { super.onCharacteristicRead(gatt, characteristic, status); if (status == bluetoothGatt.GATT_SUCCESS) { final int sum = characteristic.getValue()[0]; runOnUiThread(new Runnable() { @Override public void run() { jibu.setText("走了" + sum + "步"); } }); Log.e(TAG, "onCharacteristicRead: " + characteristic.getValue()[0]); } } @Override public void onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) { super.onCharacteristicWrite(gatt, characteristic, status); } //获取返回 数据 @Override public void onCharacteristicChanged(BluetoothGatt gatt, final BluetoothGattCharacteristic characteristic) { super.onCharacteristicChanged(gatt, characteristic); Log.i(TAG, "onCharacteristicChanged: 获取回调方法"); Log.e("", "命令:" + HexUtil.encodeHexStr(characteristic.getValue())); final byte[] values = characteristic.getValue(); runOnUiThread(new Runnable() { @Override public void run() { Toast.makeText(MainActivity.this, HexUtil.encodeHexStr(values), Toast.LENGTH_SHORT).show(); } }); } }; private boolean enableNotification(boolean enable, BluetoothGattCharacteristic characteristic) { if (bluetoothGatt == null || characteristic == null) return false; if (!bluetoothGatt.setCharacteristicNotification(characteristic, enable)) return false; BluetoothGattDescriptor clientConfig = characteristic.getDescriptor(UUID.fromString("00002902-0000-1000-8000-00805f9b34fb")); if (clientConfig == null) return false; if (enable) { clientConfig.setValue(BluetoothGattDescriptor.ENABLE_NOTIFICATION_VALUE); } else { clientConfig.setValue(BluetoothGattDescriptor.DISABLE_NOTIFICATION_VALUE); } return bluetoothGatt.writeDescriptor(clientConfig); } }
今天就写这些,下次要实现震动方法咯!是不是很激动呢~~
嘿嘿嘿~
大家加油啦~~