android - 如何识别Eddystone URL和uid？

Question

我希望在不使用 Proximity Beacon API 或 Nearby Messages API 的情况下检测 Eddystone Ul 和 uid。我希望使用 BluetoothAdapter 或 BluetoothGatt 或 BluetoothGap 等原生 android 库来解析 eddystone 帧。这可行吗？如果是这样的话，如果不可行，那么还有什么选择呢？

Answer 1

以下是获取有关 Eddystone 的信息的最简单方法 AFAIK。

// onLeScan() method of BluetoothAdapter.LeScanCallback interface.
public void onLeScan(BluetoothDevice device, int rssi, byte[] scanRecord)
{
    // Parse the payload of the advertisement packet
    // as a list of AD structures.
    List<ADStructure> structures =
        ADPayloadParser.getInstance().parse(scanRecord);

    // For each AD structure contained in the advertisement packet.
    for (ADStructure structure : structures)
    {
        // If the AD structure represents Eddystone UID.
        if (structure instanceof EddystoneUID)
        {
            // Eddystone UID
            EddystoneUID es = (EddystoneUID)structure;

            Log.d(TAG, "Tx Power = "     + es.getTxPower());
            Log.d(TAG, "Namespace ID = " + es.getNamespaceIdAsString());
            Log.d(TAG, "Instance ID = "  + es.getInstanceIdAsString());
            Log.d(TAG, "Beacon ID = "    + es.getBeaconIdAsString());

            // As byte arrays if you want.
            byte[] namespaceId = es.getNamespaceId();
            byte[] instanceId  = es.getInstanceId();
            byte[] beaconId    = es.getBeaconId();
        }
        // If the AD structure represents Eddystone URL.
        else if (structure instanceof EddystoneURL)
        {
            // Eddystone URL
            EddystoneURL es = (EddystoneURL)structure;

            Log.d(TAG, "Tx Power = " + es.getTxPower());
            Log.d(TAG, "URL = "      + es.getURL());
        }
        // If the AD structure represents Eddystone TLM.
        else if (structure instanceof EddystoneTLM)
        {
            // Eddystone TLM
            EddystoneTLM es = (EddystoneTLM)structure;

            Log.d(TAG, "TLM Version = "         + es.getTLMVersion());
            Log.d(TAG, "Battery Voltage = "     + es.getBatteryVoltage());
            Log.d(TAG, "Beacon Temperature = "  + es.getBeaconTemperature());
            Log.d(TAG, "Advertisement Count = " + es.getAdvertisementCount());
            Log.d(TAG, "Elapsed Time = "        + es.getElapsedTime());
        }
    }
}

您不必了解 Eddystone specification 的详细信息如果你使用 nv-bluetooth .

Gradle

dependencies {
    compile 'com.neovisionaries:nv-bluetooth:1.7'
}

Java文档

JavaDoc

备忘录

信标温度 Eddystone TLM以带符号的定点符号表示。 How to detect Eddystone-Compatible Beacons 中的代码示例(Android Beacon 库)在撰写本文时没有展示如何将数据提取为 float 。另一方面，<a href="http://takahikokawasaki.github.io/nv-bluetooth/com/neovisionaries/bluetooth/ble/advertising/EddystoneTLM.html" rel="noreferrer noopener nofollow">EddystoneTLM</a> nv-bluetooth 中的类有如下所示的方法，因此您不必解码定点符号。

public float getBeaconTemperature();

同样，<a href="http://takahikokawasaki.github.io/nv-bluetooth/com/neovisionaries/bluetooth/ble/advertising/EddystoneURL.html" rel="noreferrer noopener nofollow">EddystoneURL</a>类有一个方法来获取 URL 作为 URL .

public URL getURL();

因此，当您使用 Android Beacon Library 时，您不必执行如下所示的步骤。

String url = UrlBeaconUrlCompressor.uncompress(beacon.getId1().toByteArray());

nv-bluetooth将Eddystone相关的数据结构实现为继承树，如下图。这种合适的继承树在其他库中很难找到。

ADStructure
  |
  +-- ServiceData
        |
        +-- Eddystone
              |
              +-- EddystoneUID
              |
              +-- EddystoneURL
              |
              +-- EddystoneTLM

适当的继承树的好处之一是方法被放置在正确的位置。像这样:

ADStructure
  |  // AD Structure Length - 1
  |  int getLength();
  |
  |  // AD Type
  |  int getType();
  |
  |  // AD Data
  |  byte[] getData();
  |
  +-- ServiceData
  |     |  // Service UUID
  |     |  UUID getServiceUUID();
  |     |
  |     +-- Eddystone
  |           |  // Eddystone Frame Type
  |           |  FrameType getFrameType();
  |           |
  |           +-- EddystoneUID
  |           |     // Tx Power
  |           |     int getTxPower();
  |           |
  |           |     // Namespace ID (byte[])
  |           |     byte[] getNamespaceId();
  |           |
  |           |     // Instance ID (byte[])
  |           |     byte[] getInstanceId();
  |           |
  |           |     // Beacon ID (byte[])
  |           |     byte[] getBeaconId();
  |           |
  |           |     // Namespace ID (String)
  |           |     String getNamespaceIdAsString();
  |           |
  |           |     // Instance ID (String)
  |           |     String getInstanceIdAsString();
  |           |
  |           |     // Beacon ID (String)
  |           |     String getBeaconIdAsString();
  |           |
  |           +-- EddystoneURL
  |           |     // Tx Power
  |           |     int getTxPower();
  |           |
  |           |     // URL
  |           |     URL getURL();
  |           |
  |           +-- EddystoneTLM
  |                 // TLM Version
  |                 int getTLMVersion();
  |
  |                 // Battery Voltage
  |                 int getBatteryVoltage();
  |
  |                 // Beacon Temperature
  |                 float getBeaconTemperature();
  |
  |                 // Advertisement Count
  |                 long getAdvertisementCount();
  |
  |                 // Elapsed Time
  |                 long getElapsedTime();
  |
  +-- ADManufacturerSpecific
  |      |  // Company ID
  |      |  int getCompanyId();
  |      |
  |      +-- IBeacon
  |      |     // Major Number
  |      |     int getMajor();
  |      |
  |      |     (abbrev)
  |      |
  |      +-- Ucode
  |      |     // Ucode
  |      |     String getUcode();
  |      |
  |      |     (abbrev)