BLE 安卓APP控制LED灯的实现(转)

时间:2022-02-19 12:42:48

源:BLE 安卓APP控制LED灯的实现

//注:参考AmoMcu源代码修改。

打开APP,检查蓝牙是否打开

BluetoothAdapter mBluetoothAdapter;

 final BluetoothManager bluetoothManager =(BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
mBluetoothAdapter = bluetoothManager.getAdapter(); // Ensures Bluetooth is available on the device and it is enabled. If not,
// displays a dialog requesting user permission to enable Bluetooth.
if (mBluetoothAdapter == null || !mBluetoothAdapter.isEnabled()) {
Intent enableBtIntent = new Intent(BluetoothAdapter.ACTION_REQUEST_ENABLE);
startActivityForResult(enableBtIntent, REQUEST_ENABLE_BT);
}

蓝牙扫描

private void scanLeDevice(final boolean enable) {
if (enable) {
// Stops scanning after a pre-defined scan period.
mHandler.postDelayed(new Runnable() {
@Override
public void run() {
mScanning = false;
mBluetoothAdapter.stopLeScan(mLeScanCallback);
}
}, SCAN_PERIOD); mScanning = true;
mBluetoothAdapter.startLeScan(mLeScanCallback);
} else {
mScanning = false;
mBluetoothAdapter.stopLeScan(mLeScanCallback);
}
}

连接GATT服务
绑定一个服务

Intent gattServiceIntent = new Intent(this, BluetoothLeService.class);
bindService(gattServiceIntent, mServiceConnection, BIND_AUTO_CREATE);
注:BluetoothLeService.java,属于安卓源代码,可以到网上下载回来。
// Code to manage Service lifecycle.
private final ServiceConnection mServiceConnection = new ServiceConnection() {
@Override
public void onServiceConnected(ComponentName componentName, IBinder service) {
mBluetoothLeService = ((BluetoothLeService.LocalBinder) service).getService();
if (!mBluetoothLeService.initialize()) {
Log.e(TAG, "Unable to initialize Bluetooth");
finish();
}
// Automatically connects to the device upon successful start-up initialization.
mBluetoothLeService.connect(mDeviceAddress);
}
@Override
public void onServiceDisconnected(ComponentName componentName) {
mBluetoothLeService = null;
}
};

点击某个特征值的响应:
获取前面的数据,不用再次扫描,由扫描页面得到的数据,传过来的

b=getIntent().getExtras();
tv_addr.setText(b.getString(EXTRAS_DEVICE_ADDRESS));
mDeviceAddress=b.getString(EXTRAS_DEVICE_ADDRESS);
tv_name.setText(b.getString(EXTRAS_DEVICE_NAME));
mDeviceName=b.getString(EXTRAS_DEVICE_NAME);
tv_rssi.setText(b.getString(EXTRAS_DEVICE_RSSI)); lv=(ExpandableListView)this.findViewById(R.id.expandableListView1);
lv.setOnChildClickListener(servicesListClickListner); private final ExpandableListView.OnChildClickListener servicesListClickListner =
new ExpandableListView.OnChildClickListener() {
@Override
public boolean onChildClick(ExpandableListView parent, View v, int groupPosition,
int childPosition, long id) { if (mGattCharacteristics != null) {
final BluetoothGattCharacteristic characteristic =
mGattCharacteristics.get(groupPosition).get(childPosition); //当前目标特征值
target_chara=characteristic; final int charaProp = characteristic.getProperties(); if ((charaProp | BluetoothGattCharacteristic.PROPERTY_NOTIFY) > 0) {
mNotifyCharacteristic = characteristic; mBluetoothLeService.setCharacteristicNotification(
characteristic, true);
}
tv_uuid.setText(characteristic.getUuid().toString());
Intent intent=new Intent();
b.putString("CONNET_SATE", status);
b.putString("UUID", characteristic.getUuid().toString());
intent.putExtras(b);
intent.setClass(MyGattDetail.this, LEDControl.class);
startActivity(intent); return true;
} return false; } };

读写特征值的数据
读数据:

private static BluetoothGattCharacteristic myCharacteristic=null;
private static BluetoothLeService mBluetoothLeService;
mBluetoothLeService.readCharacteristic(myCharacteristic);

注释:readCharacteristic该函数会调用BluetoothGatt.readCharacteristic(BluetoothGattCharacteristic characteristic)

写数据:
mBluetoothLeService.writeCharacteristic(myCharacteristic);
注释:writeCharacteristic该函数会调用BluetoothGatt.writeCharacteristic(BluetoothGattCharacteristic characteristic)

示例代码:

private char[] buffer =new char [] {0x6F,0x0F,0x0F,0x0F,0x0F,0x0F};
private void send() {
MyGattDetail.write(ConvertString(buffer));
} private String ConvertString(char buffer[]){
String nRcvString;
StringBuffer tStringBuf=new StringBuffer ();
tStringBuf.append(buffer);
nRcvString=tStringBuf.toString();
return nRcvString;
} device_name = (TextView) findViewById(R.id.ledpage_devname); ledButton1 = (ToggleButton) findViewById(R.id.ledpage_led1);
ledButton1.setOnCheckedChangeListener(new OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView,
boolean isChecked) {
if(isChecked){
buffer[1]=0x01;
}else{
buffer[1]=0x00;
}
send();
}
}); ledButton2 = (ToggleButton) findViewById(R.id.ledpage_led2);
ledButton2.setOnCheckedChangeListener(new OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView,
boolean isChecked) {
if(isChecked){
buffer[2]=0x01; }else{
buffer[2]=0x00;
}
send();
}
});
ledButton3 = (ToggleButton) findViewById(R.id.ledpage_led3);
ledButton3.setOnCheckedChangeListener(new OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView,
boolean isChecked) {
// TODO Auto-generated method stub
if(isChecked){
buffer[3]=0x01;
}else{
buffer[3]=0x00;
}
send();
}
}); ledButton4 = (ToggleButton) findViewById(R.id.ledpage_led4);
ledButton4.setOnCheckedChangeListener(new OnCheckedChangeListener() {
@Override
public void onCheckedChanged(CompoundButton buttonView,
boolean isChecked) {
// TODO Auto-generated method stub
if(isChecked){
buffer[4]=0x01;
}else{
buffer[4]=0x00;
}
send();
}
});

使用ToggleButton控件控制LED:

问题:

使用TI的demo会发现打开一个LED会比较慢,偶尔还会失效。也就是说会掉帧,考虑大之前的所写的关于延时值的设置,如下:

Connection Interval(GAPROLE_MIN_CONN_INTERVAL && GAPROLE_MAX_CONN_INTERVAL)- 连接间隔,在BLE的两个设备的连接中使用跳频机制。两个设备使用特定的信道发送和接收数据,然后过一段时间后再使用新的信道(BLE协议栈的链路层处理信道的切换)。两个设备在切换信道后发送和接收数据称为一个连接事件。尽管没有应用数据被发送和接收,两个设备仍旧会交换链路层数据来维持连接。这个连接间隔就是这个两个连接事件的之间的时间间隔。间隔以1.25ms为单元,连接间隔的范围的6-3200既7.5ms-4s(4000ms)之间。

由此可以看出:间隔小,适用于那些需要快速反应的任务。LED灯需要快速的反应,所以经过设置如下:

// Minimum connection interval (units of 1.25ms, 80=100ms) if automatic parameter update request is enabled

#define DEFAULT_DESIRED_MIN_CONN_INTERVAL     6//80

// Maximum connection interval (units of 1.25ms, 800=1000ms) if automatic parameter update request is enabled

#define DEFAULT_DESIRED_MAX_CONN_INTERVAL     80//800

这样子实时体验就有大大的提升。