一身转战三千里,一剑曾当百万师。这篇文章主要讲述Android 开发中 iBeacon的使用相关的知识,希望能为你提供帮助。
iBeacon的工作原理是基于Bluetooth Low Energy(BLE)低功耗蓝牙传输技术,iBeacon基站不断向四周发送蓝牙信号,当智能设备进入设定区域时,就能够收到信号。只要满足iBeacon技术标准的都可以使用,所以Android也能够支持iBeacon。Google在android4.3中支持BLE技术
定位一直是非常关键的功能。通过iBeacon基站的部署能够实现室内导航,同时通过蓝牙推送信息,iBeacon在商场零售或者一些公共服务领域如体育馆、博物馆能提供非常棒的体验。尤其是蓝牙不错传输距离、低功耗、以及信号加密使得iBeacon在移动支付领域也非常有前景。总之,iBeacon的潜力似乎是无穷大,也受到了越来越多的关注。
要了解iBeacon是如何工作首先我们要了解BLE。BLE(也称为Bluetooth Smart)最早追溯到Nokia于2006年提出的Wibree,后来融合进了蓝牙标准,成为Bluetooth4.0的一部分。目前我们经常能看到3种蓝牙设备:
- Bluetooth:只支持传统模式的蓝牙设备
- Bluetooth Smart Ready:支持传统和低功耗两种模式设备
- Bluetooth Smart:只支持低功耗蓝牙设备
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【Android 开发中 iBeacon的使用】BLE与传统的蓝牙相比最大的优势是功耗降低90%,同时传输距离增大(超过100米)、安全和稳定性提高(支持AES加密和CRC验证)。iBeacon同时有一些自己的特点:
- 无需配对,一般蓝牙设备印象中都需要配对工作。iBeacon无需配对,因为它是采用蓝牙的广播频道传送信号。
- 程序可以后台唤醒,iBeacon的信息推送需要App支持。但是我们接收iBeacon信号无需打开App,只要保证安装了,同时手机蓝牙打开。
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- UUID:厂商识别号
- Major:相当于群组号,同一个组里Beacon有相同的Major
- Minor:相当于识别群组里单个的Beacon
- TX Power:用于测量设备离Beacon的距离
- 非常近(Immediate): 大概10厘米内
- 近(Near):1米内
- 远(Far):1米外
首先是获取BluetoothAdapter对象:
[java] view plain copy
- final BluetoothManager bluetoothManager =
- (BluetoothManager) getSystemService(Context.BLUETOOTH_SERVICE);
- mBluetoothAdapter = bluetoothManager.getAdapter();
- mBluetoothAdapter.startLeScan(mLeScanCallback);
然后就是它的回调,在这里对搜索到的iBeacon设备距手机的信号强度做了一个排序
[java] view plain copy
- private BluetoothAdapter.LeScanCallback mLeScanCallback =
- new BluetoothAdapter.LeScanCallback() {
- @Override
- public void onLeScan(final BluetoothDevice device, int rssi, byte[] scanRecord) {
- final iBeacon ibeacon = iBeaconClass.fromScanData(device,rssi,scanRecord);
- addDevice(ibeacon);
- Collections.sort(mLeDevices, new Comparator< iBeacon> () {
- @Override
- public int compare(iBeacon h1, iBeacon h2) {
- return h2.rssi - h1.rssi;
- }
- });
- }
- };
[java] view plain copy
- private ArrayList< iBeacon> mLeDevices = new ArrayList< iBeacon> ();
- private void addDevice(iBeacon device) { //更新beacon信息
- if(device==null) {
- Log.d("DeviceScanActivity ", "device==null ");
- return;
- }
- for(int i=0; i< mLeDevices.size(); i++){
- String btAddress = mLeDevices.get(i).bluetoothAddress;
- if(btAddress.equals(device.bluetoothAddress)){
- mLeDevices.add(i+1, device);
- mLeDevices.remove(i);
- break;
- }
- }
- mLeDevices.add(device);
- }
[java] view plain copy
- public class iBeaconClass {
- static public class iBeacon{
- public String name;
- public int major;
- public int minor;
- public String proximityUuid;
- public String bluetoothAddress;
- public int txPower;
- public int rssi;
- }
- public static iBeacon fromScanData(BluetoothDevice device, int rssi,byte[] scanData) {
- int startByte = 2;
- boolean patternFound = false;
- while (startByte < = 5) {
- if (((int)scanData[startByte+2] & 0xff) == 0x02 & &
- ((int)scanData[startByte+3] & 0xff) == 0x15) {
- // yes! This is an iBeacon
- patternFound = true;
- break;
- }
- else if (((int)scanData[startByte] & 0xff) == 0x2d & &
- ((int)scanData[startByte+1] & 0xff) == 0x24 & &
- ((int)scanData[startByte+2] & 0xff) == 0xbf & &
- ((int)scanData[startByte+3] & 0xff) == 0x16) {
- iBeacon iBeacon = new iBeacon();
- iBeacon.major = 0;
- iBeacon.minor = 0;
- iBeacon.proximityUuid = "00000000-0000-0000-0000-000000000000";
- iBeacon.txPower = -55;
- return iBeacon;
- }
- else if (((int)scanData[startByte] & 0xff) == 0xad & &
- ((int)scanData[startByte+1] & 0xff) == 0x77 & &
- ((int)scanData[startByte+2] & 0xff) == 0x00 & &
- ((int)scanData[startByte+3] & 0xff) == 0xc6) {
- iBeacon iBeacon = new iBeacon();
- iBeacon.major = 0;
- iBeacon.minor = 0;
- iBeacon.proximityUuid = "00000000-0000-0000-0000-000000000000";
- iBeacon.txPower = -55;
- return iBeacon;
- }
- startByte++;
- }
- if (patternFound == false) {
- // This is not an iBeacon
- return null;
- }
- iBeacon iBeacon = new iBeacon();
- iBeacon.major = (scanData[startByte+20] & 0xff) * 0x100 + (scanData[startByte+21] & 0xff);
- iBeacon.minor = (scanData[startByte+22] & 0xff) * 0x100 + (scanData[startByte+23] & 0xff);
- iBeacon.txPower = (int)scanData[startByte+24]; // this one is signed
- iBeacon.rssi = rssi;
- // AirLocate:
- // 02 01 1a 1a ff 4c 00 02 15 # Apple‘s fixed iBeacon advertising prefix
- // e2 c5 6d b5 df fb 48 d2 b0 60 d0 f5 a7 10 96 e0 # iBeacon profile uuid
- // 00 00 # major
- // 00 00 # minor
- // c5 # The 2‘s complement of the calibrated Tx Power
- // Estimote:
- // 02 01 1a 11 07 2d 24 bf 16
- // 394b31ba3f486415ab376e5c0f09457374696d6f7465426561636f6e00000000000000000000000000000000000000000000000000
- byte[] proximityUuidBytes = new byte[16];
- System.arraycopy(scanData, startByte+4, proximityUuidBytes, 0, 16);
- String hexString = bytesToHexString(proximityUuidBytes);
- StringBuilder sb = new StringBuilder();
- sb.append(hexString.substring(0,8));
- sb.append("-");
- sb.append(hexString.substring(8,12));
- sb.append("-");
- sb.append(hexString.substring(12,16));
- sb.append("-");
- sb.append(hexString.substring(16,20));
- sb.append("-");
- sb.append(hexString.substring(20,32));
- iBeacon.proximityUuid = sb.toString();
- if (device != null) {
- iBeacon.bluetoothAddress = device.getAddress();
- iBeacon.name = device.getName();
- }
- return iBeacon;
- }
- public static String bytesToHexString(byte[] src){
- StringBuilder stringBuilder = new StringBuilder("");
- if (src == null || src.length < = 0) {
- return null;
- }
- for (int i = 0; i < src.length; i++) {
- int v = src[i] & 0xFF;
- String hv = Integer.toHexString(v);
- if (hv.length() < 2) {
- stringBuilder.append(0);
- }
- stringBuilder.append(hv);
- }
- return stringBuilder.toString();
- }
- }
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