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
复制代码代码如下:
BluetoothManager bluetoothManager = (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
2.2获取BluetoothAdapter
复制代码代码如下:
BluetoothAdapter mBluetoothAdapter = bluetoothManager.getAdapter();
2.3创建BluetoothAdapter.LeScanCallback
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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。
复制代码代码如下:
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
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/**
*
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;
}
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2.7连接到设备之后获取设备的服务(Service)和服务对应的Characteristic。
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//
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);
}
}
}
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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。
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public
void
wirteCharacteristic(BluetoothGattCharacteristic characteristic) { if
(mBluetoothAdapter == null
|| mBluetoothGatt == null)
{ Log.w(TAG,
"BluetoothAdapter
not initialized");
return;
}
mBluetoothGatt.writeCharacteristic(characteristic);
}
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2.9写入成功之后，开始读取设备返回来的数据。
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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); }
}
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2.10、断开连接
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/**
*
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();
}
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2.11、数据的转换方法
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//
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; }
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/**
*
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。
就拿一个我们项目中的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。