BLE 获取广告包中编码的 uuid [英] BLE obtain uuid encoded in advertising packet

问题描述

我正在尝试获取 ble 设备的 UUID.我正在关注 android 开发人员指南，到目前为止我只能获得设备名称和 rssi.我正在尝试获取扫描方法的设备的 Uuid，如下所示:

Im trying to get UUID of ble device. I was following android developers guide and so far I can get only device name and rssi. Im trying to get Uuid of the device that comes to scanning method that looks like this:

    public void onLeScan(final BluetoothDevice device, int rssi,byte[] scanRecord) {

        ParcelUuid[] myUUid =device.getUuids();
        for(ParcelUuid a :myUUid){
            Log.d("UUID",a.getUuid().toString());
        }
        String s = new String(scanRecord);
        int len = scanRecord.length;
        String scanRecords =new String(scanRecord) ;



        deviceMap.put(device.getName().toString(), rssi);
        Message msg = MainActivity.myHandler.obtainMessage();
        Bundle bundle = new Bundle();
        bundle.putCharSequence("dev_name", device.getName().toString());
        bundle.putCharSequence("rssi", Integer.toString(rssi));
        msg.setData(bundle);
        MainActivity.myHandler.sendMessage(msg);
   }

返回 - btif_gattc_upstreams_evt:事件 4096

this returns - btif_gattc_upstreams_evt: Event 4096

推荐答案

如果您想获取 UUID/任何其他数据，例如BLE扫描后scanRec[]字节中的Manufacturer Data，首先需要了解那些Advertisement Data包的数据格式.

If you want to get UUID / any other data e.g. Manufacturer Data out of scanRec[] bytes after BLE Scan, you first need to understand the data format of those Advertisement Data packet.

来自Bluetooth.org:

Came from Bluetooth.org:

理论太多，想看一些代码片段吗?下面的这个函数将直接打印解析的原始数据字节.现在，您需要知道每个类型的代码才能知道什么数据包指的是什么信息.例如Type : 0x09, 指BLE Device Name, Type : 0x07, 指UUID.

Too much theory, want to see some code snippet? This function below would straight forward print parsed raw data bytes. Now, you need to know each type code to know what data packet refers to what information. e.g. Type : 0x09, refers to BLE Device Name, Type : 0x07, refers to UUID.

public void printScanRecord (byte[] scanRecord) {

    // Simply print all raw bytes   
    try {
        String decodedRecord = new String(scanRecord,"UTF-8");
        Log.d("DEBUG","decoded String : " + ByteArrayToString(scanRecord));
    } catch (UnsupportedEncodingException e) {
        e.printStackTrace();
    }

    // Parse data bytes into individual records
    List<AdRecord> records = AdRecord.parseScanRecord(scanRecord);


    // Print individual records 
    if (records.size() == 0) {
        Log.i("DEBUG", "Scan Record Empty");
    } else {
        Log.i("DEBUG", "Scan Record: " + TextUtils.join(",", records));
    }

}


public static String ByteArrayToString(byte[] ba)
{
  StringBuilder hex = new StringBuilder(ba.length * 2);
  for (byte b : ba)
    hex.append(b + " ");

  return hex.toString();
}


public static class AdRecord {

    public AdRecord(int length, int type, byte[] data) {
        String decodedRecord = "";
        try {
            decodedRecord = new String(data,"UTF-8");

        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        }

        Log.d("DEBUG", "Length: " + length + " Type : " + type + " Data : " + ByteArrayToString(data));         
    }

    // ...

    public static List<AdRecord> parseScanRecord(byte[] scanRecord) {
        List<AdRecord> records = new ArrayList<AdRecord>();

        int index = 0;
        while (index < scanRecord.length) {
            int length = scanRecord[index++];
            //Done once we run out of records
            if (length == 0) break;

            int type = scanRecord[index];
            //Done if our record isn't a valid type
            if (type == 0) break;

            byte[] data = Arrays.copyOfRange(scanRecord, index+1, index+length);

            records.add(new AdRecord(length, type, data));
            //Advance
            index += length;
        }

        return records;
    }

    // ...
}

经过这个解析，那些数据字节会更有意义，你可以找出下一级的解码.

After this parsing, those data bytes would make more sense, and you can figure out next level of decoding.

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