蓝牙开发、扫描、通知、发送指令
2021-06-16 本文已影响0人
maiduoduo
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
作者：norkm
链接：https://www.jianshu.com/p/cdb5bc8f9d85
来源：简书
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