Android 蓝牙4.0(ble)开发的解决方案
最近，随着智能穿戴式设备、智能医疗以及智能家居的普及，蓝牙开发在移动开中显得非常的重要。由于公司需要，研究了一下，蓝牙4.0在Android中的应用。以下是我的一些总结。
1.先介绍一下关于蓝牙4.0中的一些名词吧：
(1)GATT(Gneric Attibute Profile)
通过ble连接，读写属性类小数据Profile通用的规范。现在所有的ble应用Profile 都是基于GATT(2)ATT(Attribute Protocal)
GATT是基于ATT Potocal的ATT针对BLE设备专门做的具体就是传输过程中使用尽量少的数据，每个属性都有个唯一的UUID，属性chartcteristics and Service的形式传输。
(3)Service是Characteristic的集合。(4).Characteristic 特征类型。
比如。有个蓝牙ble的血压计。他可能包括多个Servvice，每个Service有包括多个Characteristic
注意：蓝牙ble只能支持Android 4.3以上的系统 SDK>=18
2.以下是开发的步骤：
2.1首先获取BluetoothManager
BluetoothManager bluetoothManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);2.2获取BluetoothAdapter
BluetoothAdapter mBluetoothAdapter = bluetoothManager.getAdapter();
2.3创建BluetoothAdapter.LeScanCallback
private BluetoothAdapter.LeScanCallback mLeScanCallback = new BluetoothAdapter.LeScanCallback() {
@Override
public void onLeScan(final BluetoothDevice device, int rssi, final byte[] scanRecord) {
runOnUiThread(new Runnable() {
@Override
public void run() {
try {
String struuid = NumberUtils.bytes2HexString(NumberUtils.reverseBytes(scanRecord)).replace("-", "").toLowerCase();
if (device!=null && struuid.contains(DEVICE_UUID_PREFIX.toLowerCase())) {
mBluetoothDevices.add(device);
}
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
};
2.4.开始搜索设备。
mBluetoothAdapter.startLeScan(mLeScanCallback);
2.5.BluetoothDevice 描述了一个蓝牙设备 提供了getAddress()设备Mac地址,getName()设备的名称。
2.6开始连接设备
/**
* Connects to the GATT server hosted on the Bluetooth LE device.
*
* @param address
* The device address of the destination device.
*
* @return Return true if the connection is initiated successfully. The
* connection result is reported asynchronously through the
* {@code BluetoothGattCallback#onConnectionStateChange(android.bluetooth.BluetoothGatt, int, int)}
* callback.
*/
public boolean connect(final String address) {
if (mBluetoothAdapter == null || address == null) {
Log.w(TAG, "BluetoothAdapter not initialized or unspecified address.");
return false;
}
// Previously connected device. Try to reconnect. (先前连接的设备。 尝试重新连接)
if (mBluetoothDeviceAddress != null && address.equals(mBluetoothDeviceAddress) && mBluetoothGatt != null) {
Log.d(TAG, "Trying to use an existing mBluetoothGatt for connection.");
if (mBluetoothGatt.connect()) {
mConnectionState = STATE_CONNECTING;
return true;
} else {
return false;
}
}
final BluetoothDevice device = mBluetoothAdapter.getRemoteDevice(address);
if (device == null) {
Log.w(TAG, "Device not found. Unable to connect.");
return false;
}
// We want to directly connect to the device, so we are setting the
// autoConnect
// parameter to false.
mBluetoothGatt = device.connectGatt(this, false, mGattCallback);
Log.d(TAG, "Trying to create a new connection.");
mBluetoothDeviceAddress = address;
mConnectionState = STATE_CONNECTING;
return true;
} 2.7连接到设备之后获取设备的服务(Service)和服务对应的Characteristic。
// Demonstrates how to iterate through the supported GATT
// Services/Characteristics.
// In this sample, we populate the data structure that is bound to the
// ExpandableListView
// on the UI.
private void displayGattServices(List<BluetoothGattService> gattServices) {
if (gattServices == null)
return;
String uuid = null;
ArrayList<HashMap<String, String>> gattServiceData = new ArrayList<>();
ArrayList<ArrayList<HashMap<String, String>>> gattCharacteristicData = new ArrayList<>();
mGattCharacteristics = new ArrayList<>();
// Loops through available GATT Services.
for (BluetoothGattService gattService : gattServices) {
HashMap<String, String> currentServiceData = new HashMap<>();
uuid = gattService.getUuid().toString();
if (uuid.contains("ba11f08c-5f14-0b0d-1080")) {//服务的uuid
//System.out.println("this gattService UUID is:" + gattService.getUuid().toString());
currentServiceData.put(LIST_NAME, "Service_OX100");
currentServiceData.put(LIST_UUID, uuid);
gattServiceData.add(currentServiceData);
ArrayList<HashMap<String, String>> gattCharacteristicGroupData = new ArrayList<>();
List<BluetoothGattCharacteristic> gattCharacteristics = gattService.getCharacteristics();
ArrayList<BluetoothGattCharacteristic> charas = new ArrayList<>();
// Loops through available Characteristics.
for (BluetoothGattCharacteristic gattCharacteristic : gattCharacteristics) {
charas.add(gattCharacteristic);
HashMap<String, String> currentCharaData = new HashMap<>();
uuid = gattCharacteristic.getUuid().toString();
if (uuid.toLowerCase().contains("cd01")) {
currentCharaData.put(LIST_NAME, "cd01");
} else if (uuid.toLowerCase().contains("cd02")) {
currentCharaData.put(LIST_NAME, "cd02");
} else if (uuid.toLowerCase().contains("cd03")) {
currentCharaData.put(LIST_NAME, "cd03");
} else if (uuid.toLowerCase().contains("cd04")) {
currentCharaData.put(LIST_NAME, "cd04");
} else {
currentCharaData.put(LIST_NAME, "write");
}
currentCharaData.put(LIST_UUID, uuid);
gattCharacteristicGroupData.add(currentCharaData);
}
mGattCharacteristics.add(charas);
gattCharacteristicData.add(gattCharacteristicGroupData);
mCharacteristicCD01 = gattService.getCharacteristic(UUID.fromString("0000cd01-0000-1000-8000-00805f9b34fb"));
mCharacteristicCD02 = gattService.getCharacteristic(UUID.fromString("0000cd02-0000-1000-8000-00805f9b34fb"));
mCharacteristicCD03 = gattService.getCharacteristic(UUID.fromString("0000cd03-0000-1000-8000-00805f9b34fb"));
mCharacteristicCD04 = gattService.getCharacteristic(UUID.fromString("0000cd04-0000-1000-8000-00805f9b34fb"));
mCharacteristicWrite = gattService.getCharacteristic(UUID.fromString("0000cd20-0000-1000-8000-00805f9b34fb"));
//System.out.println("=======================Set Notification==========================");
// 开始顺序监听，第一个：CD01
mBluetoothLeService.setCharacteristicNotification(mCharacteristicCD01, true);
mBluetoothLeService.setCharacteristicNotification(mCharacteristicCD02, true);
mBluetoothLeService.setCharacteristicNotification(mCharacteristicCD03, true);
mBluetoothLeService.setCharacteristicNotification(mCharacteristicCD04, true);
}
}
}2.8获取到特征之后，找到服务中可以向下位机写指令的特征，向该特征写入指令。
public void wirteCharacteristic(BluetoothGattCharacteristic characteristic) {
if (mBluetoothAdapter == null || mBluetoothGatt == null) {
Log.w(TAG, "BluetoothAdapter not initialized");
return;
}
mBluetoothGatt.writeCharacteristic(characteristic);
}
2.9写入成功之后，开始读取设备返回来的数据。
private final BluetoothGattCallback mGattCallback = new BluetoothGattCallback() {
@Override
public void onConnectionStateChange(BluetoothGatt gatt, int status, int newState) {
String intentAction;
//System.out.println("=======status:" + status);
if (newState == BluetoothProfile.STATE_CONNECTED) {
intentAction = ACTION_GATT_CONNECTED;
mConnectionState = STATE_CONNECTED;
broadcastUpdate(intentAction);
Log.i(TAG, "Connected to GATT server.");
// Attempts to discover services after successful connection.
Log.i(TAG, "Attempting to start service discovery:" + mBluetoothGatt.discoverServices());
} else if (newState == BluetoothProfile.STATE_DISCONNECTED) {
intentAction = ACTION_GATT_DISCONNECTED;
mConnectionState = STATE_DISCONNECTED;
Log.i(TAG, "Disconnected from GATT server.");
broadcastUpdate(intentAction);
}
}
@Override
public void onServicesDiscovered(BluetoothGatt gatt, int status) {
if (status == BluetoothGatt.GATT_SUCCESS) {
broadcastUpdate(ACTION_GATT_SERVICES_DISCOVERED);
} else {
Log.w(TAG, "onServicesDiscovered received: " + status);
}
}
//从特征中读取数据
@Override
public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
//System.out.println("onCharacteristicRead");
if (status == BluetoothGatt.GATT_SUCCESS) {
broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic);
}
}
//向特征中写入数据
@Override
public void onCharacteristicWrite(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
//System.out.println("--------write success----- status:" + status);
}
/*
* when connected successfully will callback this method this method can
* dealwith send password or data analyze
*当连接成功将回调该方法
*/
@Override
public void onCharacteristicChanged(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic) {
broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic);
if (characteristic.getValue() != null) {
//System.out.println(characteristic.getStringValue(0));
}
//System.out.println("--------onCharacteristicChanged-----");
}
@Override
public void onDescriptorWrite(BluetoothGatt gatt, BluetoothGattDescriptor descriptor, int status) {
//System.out.println("onDescriptorWriteonDescriptorWrite = " + status + ", descriptor =" + descriptor.getUuid().toString());
UUID uuid = descriptor.getCharacteristic().getUuid();
if (uuid.equals(UUID.fromString("0000cd01-0000-1000-8000-00805f9b34fb"))) {
broadcastUpdate(ACTION_CD01NOTIDIED);
} else if (uuid.equals(UUID.fromString("0000cd02-0000-1000-8000-00805f9b34fb"))) {
broadcastUpdate(ACTION_CD02NOTIDIED);
} else if (uuid.equals(UUID.fromString("0000cd03-0000-1000-8000-00805f9b34fb"))) {
broadcastUpdate(ACTION_CD03NOTIDIED);
} else if (uuid.equals(UUID.fromString("0000cd04-0000-1000-8000-00805f9b34fb"))) {
broadcastUpdate(ACTION_CD04NOTIDIED);
}
}
@Override
public void onReadRemoteRssi(BluetoothGatt gatt, int rssi, int status) {
//System.out.println("rssi = " + rssi);
}
};
----------------------------------------------
//从特征中读取数据
@Override
public void onCharacteristicRead(BluetoothGatt gatt, BluetoothGattCharacteristic characteristic, int status) {
//System.out.println("onCharacteristicRead");
if (status == BluetoothGatt.GATT_SUCCESS) {
broadcastUpdate(ACTION_DATA_AVAILABLE, characteristic);
}
}
2.10、断开连接
/**
* Disconnects an existing connection or cancel a pending connection. The
* disconnection result is reported asynchronously through the
* {@code BluetoothGattCallback#onConnectionStateChange(android.bluetooth.BluetoothGatt, int, int)}
* callback.
*/
public void disconnect() {
if (mBluetoothAdapter == null || mBluetoothGatt == null) {
Log.w(TAG, "BluetoothAdapter not initialized");
return;
}
mBluetoothGatt.disconnect();
}
2.11、数据的转换方法
// byte转十六进制字符串
public static String bytes2HexString(byte[] bytes) {
String ret = "";
for (byte aByte : bytes) {
String hex = Integer.toHexString(aByte & 0xFF);
if (hex.length() == 1) {
hex = '0' + hex;
}
ret += hex.toUpperCase(Locale.CHINA);
}
return ret;
}
/**
* 将16进制的字符串转换为字节数组
*
* @param message
* @return 字节数组
*/
public static byte[] getHexBytes(String message) {
int len = message.length() / 2;
char[] chars = message.toCharArray();
String[] hexStr = new String[len];
byte[] bytes = new byte[len];
for (int i = 0, j = 0; j < len; i += 2, j++) {
hexStr[j] = "" + chars[i] + chars[i + 1];
bytes[j] = (byte) Integer.parseInt(hexStr[j], 16);
}
return bytes;
}
大概整体就是如上的步骤。但是也是要具体根据厂家的协议来实现通信的过程。
就那一个我们项目中的demo说一下。
一个蓝牙ble的血压计。 上位机---手机 下位机 -- 血压计
1.血压计与手机连接蓝牙之后。
2.上位机主动向下位机发送一个身份验证指令，下位机收到指令后开始给上位做应答，
3.应答成功，下位机会将测量的血压数据传送到上位机。
4.最后断开连接。