Android 蓝牙4.0详细
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
?
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
|
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
?
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
|
/**
* 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。
?
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
|
// 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
if
(gattServices ==
null
)
return
;
String uuid =
null
;
ArrayList
new
ArrayList<>();
ArrayList
new
ArrayList<>();
mGattCharacteristics =
new
ArrayList<>();
// Loops through available GATT Services.
for
(BluetoothGattService gattService : gattServices) {
HashMap
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
new
ArrayList<>();
List
ArrayList
new
ArrayList<>();
// Loops through available Characteristics.
for
(BluetoothGattCharacteristic gattCharacteristic : gattCharacteristics) {
charas.add(gattCharacteristic);
HashMap
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。
?
|
1
2
3
4
5
6
7
8
9
10
|
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。
?
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
|
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
?
|
1
2
3
4
5
6
7
8
9
10
11
12
13
|
/**
* 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
?
|
1
2
3
4
5
6
7
8
9
10
11
12
|
// 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;
}
|
?
|
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
|
/**
* 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。