具有 128 位 UUID 的 startLeScan 不适用于本机 Android BLE 实现

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【中文标题】具有 128 位 UUID 的 startLeScan 不适用于本机 Android BLE 实现【英文标题】:startLeScan with 128 bit UUIDs doesn't work on native Android BLE implementation 【发布时间】:2013-08-03 20:35:29 【问题描述】:

我在 Nexus 4 上使用新推出的 android 4.3 BLE API 时遇到了问题。

回调只是没有被调用。我仍然可以在日志中看到传入的包:

08-02 15:48:57.985: I/bt-hci(1051): btu_ble_process_adv_pkt
08-02 15:48:58.636: I/bt-hci(1051): BLE HCI(id=62) event = 0x02)

如果我不使用该参数来过滤 UUID,它会起作用。我们正在为我们公司的设备使用制造商特定的 128 位 UUID

现在,我们的设备提供的服务比我在阵列中提供的更多。但这应该不是问题。

有人遇到同样的问题吗?有什么解决办法吗?

编辑

扫描有几个问题,本题只讨论一个:如果你也有扫描方面的问题,请先阅读this comment。还要记住,我的设备强制使用 16 位和 128 位 UUID。你们中的大多数人使用 BLE 标准提供的 16 位 UUID,例如心率或速度和节奏。

【问题讨论】:

我在 Nexus 4、4.3 构建 JWR66Y 上看到了这个确切的问题。当我不包含任何 UUID 时,它甚至会发生。有时我需要重启,有时我会在重启范围内的 BLE 设备时开始收到回调。 @JonWillis 请不要混淆三个问题:1st BLE 一般不稳定(根本不接收扫描结果)和2nd Nexus 4只报告一个扫描结果,3rd 无法正确过滤扫描结果(这个问题)。从第一个问题开始:见***.com/questions/17870189/…。一种解决方法是禁用 wifi 并在蓝牙不起作用时重新启动它。从第二个问题开始:另外请记住,Nexus 4 在一次扫描中只为每台设备显示一个扫描结果。如果要不断扫描结果,则需要重新启动扫描。 感谢您的信息。当我同时遇到这三个问题时,很难不将这些问题混为一谈。 请注意,根据 BLE 规范,“每次扫描每个设备一个扫描结果”实际上是非常好的行为。你应该期待它。 【参考方案1】:

@Navin 的代码不错,但它包含原始 16 位 Android 代码的溢出错误。 (如果任一字节大于 127 则变为负整数。)

这是一个修复该错误的实现并且添加了 128 位支持:

private List<UUID> parseUuids(byte[] advertisedData) 
     List<UUID> uuids = new ArrayList<UUID>();

     ByteBuffer buffer = ByteBuffer.wrap(advertisedData).order(ByteOrder.LITTLE_ENDIAN);
     while (buffer.remaining() > 2) 
         byte length = buffer.get();
         if (length == 0) break;

         byte type = buffer.get();
         switch (type) 
             case 0x02: // Partial list of 16-bit UUIDs
             case 0x03: // Complete list of 16-bit UUIDs
                 while (length >= 2) 
                     uuids.add(UUID.fromString(String.format(
                             "%08x-0000-1000-8000-00805f9b34fb", buffer.getShort())));
                     length -= 2;
                 
                 break;

             case 0x06: // Partial list of 128-bit UUIDs
             case 0x07: // Complete list of 128-bit UUIDs
                 while (length >= 16) 
                     long lsb = buffer.getLong();
                     long msb = buffer.getLong();
                     uuids.add(new UUID(msb, lsb));
                     length -= 16;
                 
                 break;

             default:
                 buffer.position(buffer.position() + length - 1);
                 break;
         
     

     return uuids;
 

【讨论】:

也许你能解释一下这段代码如何更好?它可能会提高新手用户或一般用户的实用性。 这是来自 GattService 吗?如果是这样,我该如何以及在哪里扩展它?【参考方案2】:

试试这个从广告的 128 位 UUID 中检索/过滤设备:

private List<UUID> parseUUIDs(final byte[] advertisedData) 
    List<UUID> uuids = new ArrayList<UUID>();

    int offset = 0;
    while (offset < (advertisedData.length - 2)) 
        int len = advertisedData[offset++];
        if (len == 0)
            break;

        int type = advertisedData[offset++];
        switch (type) 
        case 0x02: // Partial list of 16-bit UUIDs
        case 0x03: // Complete list of 16-bit UUIDs
            while (len > 1) 
                int uuid16 = advertisedData[offset++];
                uuid16 += (advertisedData[offset++] << 8);
                len -= 2;
                uuids.add(UUID.fromString(String.format(
                        "%08x-0000-1000-8000-00805f9b34fb", uuid16)));
            
            break;
        case 0x06:// Partial list of 128-bit UUIDs
        case 0x07:// Complete list of 128-bit UUIDs
            // Loop through the advertised 128-bit UUID's.
            while (len >= 16) 
                try 
                    // Wrap the advertised bits and order them.
                    ByteBuffer buffer = ByteBuffer.wrap(advertisedData,
                            offset++, 16).order(ByteOrder.LITTLE_ENDIAN);
                    long mostSignificantBit = buffer.getLong();
                    long leastSignificantBit = buffer.getLong();
                    uuids.add(new UUID(leastSignificantBit,
                            mostSignificantBit));
                 catch (IndexOutOfBoundsException e) 
                    // Defensive programming.
                    Log.e(LOG_TAG, e.toString());
                    continue;
                 finally 
                    // Move the offset to read the next uuid.
                    offset += 15;
                    len -= 16;
                
            
            break;
        default:
            offset += (len - 1);
            break;
        
    

    return uuids;

【讨论】:

确保不要在扫描请求中添加 UUID 过滤器,以便返回所有通告的外围设备,并且可以从应用程序代码完成过滤。 以上效果很好,谢谢。似乎有很多sn-ps,但这是唯一真正完成这项工作的。 我同意@BenClayton。来自谷歌票的代码不起作用。我一直在尝试使用它。我使用这个版本的 parseUUID 方法在我的测试中取得了成功。 code.google.com/p/android/issues/… 效果很好!谢谢!! 对不起,我应该在什么时候使用这个解析器?我试试:List&lt;UUID&gt; uuids = parseUUIDs("0000ffe0-0000-1000-8000-00805f9b34fb".getBytes());List&lt;UUID&gt; uuids = parseUUIDs("0000ffe0".getBytes());List&lt;UUID&gt; uuids = parseUUIDs("ffe0".getBytes());【参考方案3】:

至少在 Android 4.3 JWR66Y 中这是一个reported bug:

如果我提供我的 16 位 UUID,则过滤有效 如果我提供 128 位 UUID 或同时提供两个 UUID,过滤不会返回任何扫描结果

我的设置:我的设备提供 2 个用于广告的 UUID (1 16bit and 1 128bit) 和 4 个用于服务发现的 UUID(1 128 位和 3 个 16 位)。

即使它得到修复,我也警告大家不要使用 Android 提供的过滤器选项。为了向后兼容,因为它在搭载 Android 4.3 的三星 Galaxy S3 上已损坏

【讨论】:

【参考方案4】:

虽然 4.3 似乎不支持按 128 位 UUID 过滤,但这些 UUID 很可能存在于 LeScanCallback 返回的 byte[] scanRecord 中。

可能有一种正确的方法来解析这些数据,但如果您每次都获得相同的数据,您可以通过查找您正在寻找的 UUID 的偏移量来手动过滤结果。您可以通过将扫描数据打印到日志(作为十六进制字符串)并查找您感兴趣的 UUID 来执行此操作(它们可能会跟随 0x06 或 0x07 并且将被反转)。找到偏移量后,设置基本过滤器应该不会太难。

这是一个按单个 UUID 过滤的简单示例(ArrayUtils 使用 Apache Commons Lang 和 here 找到的 bytes-to-hex 方法,但您可以在必要时替换您自己的代码)

public static boolean hasMyService(byte[] scanRecord) 

    // UUID we want to filter by (without hyphens)
    final String myServiceID = "0000000000001000800000805F9B34FB";

    // The offset in the scan record. In my case the offset was 13; it will probably be different for you
    final int serviceOffset = 13; 

    try

        // Get a 16-byte array of what may or may not be the service we're filtering for
        byte[] service = ArrayUtils.subarray(scanRecord, serviceOffset, serviceOffset + 16);

        // The bytes are probably in reverse order, so we need to fix that
        ArrayUtils.reverse(service);

        // Get the hex string
        String discoveredServiceID = bytesToHex(service);

        // Compare against our service
        return myServiceID.equals(discoveredServiceID);

     catch (Exception e)
        return false;
    


【讨论】:

这是真的。我实际上是在扫描结果后使用这样的过滤。【参考方案5】:

您确定外设在广告数据或扫描响应数据中列出了指定的服务 UUID?

【讨论】:

是的,我想要的服务包含在广告中(就像所有主要服务一样)。它适用于三星 Galaxy S4 及其 SAMSUNG BLE SDK。 好的,那我不知道,抱歉。然而,这听起来确实像是 Android API 中的一个错误。【参考方案6】:

从扫描结果中列出服务 UUID 的最佳方法是从位于 android 内部的 ScanRecord.java 中准确复制 parseFromBytes 方法.bluetooth.le 包(确保您拥有最新的 Android SDK),将返回更改为 ParcelUuidList,因为这是我们唯一关心的事情

    private static final int DATA_TYPE_FLAGS = 0x01;
    private static final int DATA_TYPE_SERVICE_UUIDS_16_BIT_PARTIAL = 0x02;
    private static final int DATA_TYPE_SERVICE_UUIDS_16_BIT_COMPLETE = 0x03;
    private static final int DATA_TYPE_SERVICE_UUIDS_32_BIT_PARTIAL = 0x04;
    private static final int DATA_TYPE_SERVICE_UUIDS_32_BIT_COMPLETE = 0x05;
    private static final int DATA_TYPE_SERVICE_UUIDS_128_BIT_PARTIAL = 0x06;
    private static final int DATA_TYPE_SERVICE_UUIDS_128_BIT_COMPLETE = 0x07;
    private static final int DATA_TYPE_LOCAL_NAME_SHORT = 0x08;
    private static final int DATA_TYPE_LOCAL_NAME_COMPLETE = 0x09;
    private static final int DATA_TYPE_TX_POWER_LEVEL = 0x0A;
    private static final int DATA_TYPE_SERVICE_DATA = 0x16;
    private static final int DATA_TYPE_MANUFACTURER_SPECIFIC_DATA = 0xFF;

    public static List<ParcelUuid> parseFromBytes(byte[] scanRecord) 
        if (scanRecord == null) 
            return null;
        

        int currentPos = 0;
        int advertiseFlag = -1;
        List<ParcelUuid> serviceUuids = new ArrayList<ParcelUuid>();
        String localName = null;
        int txPowerLevel = Integer.MIN_VALUE;

        SparseArray<byte[]> manufacturerData = new SparseArray<byte[]>();
        Map<ParcelUuid, byte[]> serviceData = new HashMap<ParcelUuid, byte[]>();

        try 
            while (currentPos < scanRecord.length) 
                // length is unsigned int.
                int length = scanRecord[currentPos++] & 0xFF;
                if (length == 0) 
                    break;
                
                // Note the length includes the length of the field type itself.
                int dataLength = length - 1;
                // fieldType is unsigned int.
                int fieldType = scanRecord[currentPos++] & 0xFF;
                switch (fieldType) 
                    case DATA_TYPE_FLAGS:
                        advertiseFlag = scanRecord[currentPos] & 0xFF;
                        break;
                    case DATA_TYPE_SERVICE_UUIDS_16_BIT_PARTIAL:
                    case DATA_TYPE_SERVICE_UUIDS_16_BIT_COMPLETE:
                        parseServiceUuid(scanRecord, currentPos,
                                dataLength, 2, serviceUuids);
                        break;
                    case DATA_TYPE_SERVICE_UUIDS_32_BIT_PARTIAL:
                    case DATA_TYPE_SERVICE_UUIDS_32_BIT_COMPLETE:
                        parseServiceUuid(scanRecord, currentPos, dataLength,
                                BluetoothUuid.UUID_BYTES_32_BIT, serviceUuids);
                        break;
                    case DATA_TYPE_SERVICE_UUIDS_128_BIT_PARTIAL:
                    case DATA_TYPE_SERVICE_UUIDS_128_BIT_COMPLETE:
                        parseServiceUuid(scanRecord, currentPos, dataLength,
                                BluetoothUuid.UUID_BYTES_128_BIT, serviceUuids);
                        break;
                    case DATA_TYPE_LOCAL_NAME_SHORT:
                    case DATA_TYPE_LOCAL_NAME_COMPLETE:
                        localName = new String(
                                extractBytes(scanRecord, currentPos, dataLength));
                        break;
                    case DATA_TYPE_TX_POWER_LEVEL:
                        txPowerLevel = scanRecord[currentPos];
                        break;
                    case DATA_TYPE_SERVICE_DATA:
                        // The first two bytes of the service data are service data UUID in little
                        // endian. The rest bytes are service data.
                        int serviceUuidLength = BluetoothUuid.UUID_BYTES_16_BIT;
                        byte[] serviceDataUuidBytes = extractBytes(scanRecord, currentPos,
                                serviceUuidLength);
                        ParcelUuid serviceDataUuid = BluetoothUuid.parseUuidFrom(
                                serviceDataUuidBytes);
                        byte[] serviceDataArray = extractBytes(scanRecord,
                                currentPos + serviceUuidLength, dataLength - serviceUuidLength);
                        serviceData.put(serviceDataUuid, serviceDataArray);
                        break;
                    case DATA_TYPE_MANUFACTURER_SPECIFIC_DATA:
                        // The first two bytes of the manufacturer specific data are
                        // manufacturer ids in little endian.
                        int manufacturerId = ((scanRecord[currentPos + 1] & 0xFF) << 8) +
                                (scanRecord[currentPos] & 0xFF);
                        byte[] manufacturerDataBytes = extractBytes(scanRecord, currentPos + 2,
                                dataLength - 2);
                        manufacturerData.put(manufacturerId, manufacturerDataBytes);
                        break;
                    default:
                        // Just ignore, we don't handle such data type.
                        break;
                
                currentPos += dataLength;
            

            if (serviceUuids.isEmpty()) 
                serviceUuids = null;
            

//            Log.i("SERVICE UUIDS", parcelUuidToString(serviceUuids));
         catch (Exception e) 
            Log.e(TAG, "unable to parse scan record: " + Arrays.toString(scanRecord));
            // As the record is invalid, ignore all the parsed results for this packet
            // and return an empty record with raw scanRecord bytes in results
        

        return serviceUuids;
    

您还需要从同一个包中导入 BluetoothUuid.java

import java.util.UUID;
import android.os.ParcelUuid;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.util.Arrays;
import java.util.HashSet;
/**
 * Static helper methods and constants to decode the ParcelUuid of remote devices.
 *  @hide
 */
public final class BluetoothUuid 
    /* See Bluetooth Assigned Numbers document - SDP section, to get the values of UUIDs
     * for the various services.
     *
     * The following 128 bit values are calculated as:
     *  uuid * 2^96 + BASE_UUID
     */
    public static final ParcelUuid Audiosink =
            ParcelUuid.fromString("0000110B-0000-1000-8000-00805F9B34FB");
    public static final ParcelUuid AudioSource =
            ParcelUuid.fromString("0000110A-0000-1000-8000-00805F9B34FB");
    public static final ParcelUuid AdvAudioDist =
            ParcelUuid.fromString("0000110D-0000-1000-8000-00805F9B34FB");
    public static final ParcelUuid HSP =
            ParcelUuid.fromString("00001108-0000-1000-8000-00805F9B34FB");
    public static final ParcelUuid HSP_AG =
            ParcelUuid.fromString("00001112-0000-1000-8000-00805F9B34FB");
    public static final ParcelUuid Handsfree =
            ParcelUuid.fromString("0000111E-0000-1000-8000-00805F9B34FB");
    public static final ParcelUuid Handsfree_AG =
            ParcelUuid.fromString("0000111F-0000-1000-8000-00805F9B34FB");
    public static final ParcelUuid AvrcpController =
            ParcelUuid.fromString("0000110E-0000-1000-8000-00805F9B34FB");
    public static final ParcelUuid AvrcpTarget =
            ParcelUuid.fromString("0000110C-0000-1000-8000-00805F9B34FB");
    public static final ParcelUuid ObexObjectPush =
            ParcelUuid.fromString("00001105-0000-1000-8000-00805f9b34fb");
    public static final ParcelUuid Hid =
            ParcelUuid.fromString("00001124-0000-1000-8000-00805f9b34fb");
    public static final ParcelUuid Hogp =
            ParcelUuid.fromString("00001812-0000-1000-8000-00805f9b34fb");
    public static final ParcelUuid PANU =
            ParcelUuid.fromString("00001115-0000-1000-8000-00805F9B34FB");
    public static final ParcelUuid NAP =
            ParcelUuid.fromString("00001116-0000-1000-8000-00805F9B34FB");
    public static final ParcelUuid BNEP =
            ParcelUuid.fromString("0000000f-0000-1000-8000-00805F9B34FB");
    public static final ParcelUuid PBAP_PCE =
            ParcelUuid.fromString("0000112e-0000-1000-8000-00805F9B34FB");
    public static final ParcelUuid PBAP_PSE =
            ParcelUuid.fromString("0000112f-0000-1000-8000-00805F9B34FB");
    public static final ParcelUuid MAP =
            ParcelUuid.fromString("00001134-0000-1000-8000-00805F9B34FB");
    public static final ParcelUuid MNS =
            ParcelUuid.fromString("00001133-0000-1000-8000-00805F9B34FB");
    public static final ParcelUuid MAS =
            ParcelUuid.fromString("00001132-0000-1000-8000-00805F9B34FB");
    public static final ParcelUuid SAP =
            ParcelUuid.fromString("0000112D-0000-1000-8000-00805F9B34FB");

    public static final ParcelUuid BASE_UUID =
            ParcelUuid.fromString("00000000-0000-1000-8000-00805F9B34FB");
    /** Length of bytes for 16 bit UUID */
    public static final int UUID_BYTES_16_BIT = 2;
    /** Length of bytes for 32 bit UUID */
    public static final int UUID_BYTES_32_BIT = 4;
    /** Length of bytes for 128 bit UUID */
    public static final int UUID_BYTES_128_BIT = 16;
    public static final ParcelUuid[] RESERVED_UUIDS = 
            AudioSink, AudioSource, AdvAudioDist, HSP, Handsfree, AvrcpController, AvrcpTarget,
            ObexObjectPush, PANU, NAP, MAP, MNS, MAS, SAP;
    public static boolean isAudioSource(ParcelUuid uuid) 
        return uuid.equals(AudioSource);
    
    public static boolean isAudioSink(ParcelUuid uuid) 
        return uuid.equals(AudioSink);
    
    public static boolean isAdvAudioDist(ParcelUuid uuid) 
        return uuid.equals(AdvAudioDist);
    
    public static boolean isHandsfree(ParcelUuid uuid) 
        return uuid.equals(Handsfree);
    
    public static boolean isHeadset(ParcelUuid uuid) 
        return uuid.equals(HSP);
    
    public static boolean isAvrcpController(ParcelUuid uuid) 
        return uuid.equals(AvrcpController);
    
    public static boolean isAvrcpTarget(ParcelUuid uuid) 
        return uuid.equals(AvrcpTarget);
    
    public static boolean isInputDevice(ParcelUuid uuid) 
        return uuid.equals(Hid);
    
    public static boolean isPanu(ParcelUuid uuid) 
        return uuid.equals(PANU);
    
    public static boolean isNap(ParcelUuid uuid) 
        return uuid.equals(NAP);
    
    public static boolean isBnep(ParcelUuid uuid) 
        return uuid.equals(BNEP);
    
    public static boolean isMap(ParcelUuid uuid) 
        return uuid.equals(MAP);
    
    public static boolean isMns(ParcelUuid uuid) 
        return uuid.equals(MNS);
    
    public static boolean isMas(ParcelUuid uuid) 
        return uuid.equals(MAS);
    
    public static boolean isSap(ParcelUuid uuid) 
        return uuid.equals(SAP);
    
    /**
     * Returns true if ParcelUuid is present in uuidArray
     *
     * @param uuidArray - Array of ParcelUuids
     * @param uuid
     */
    public static boolean isUuidPresent(ParcelUuid[] uuidArray, ParcelUuid uuid) 
        if ((uuidArray == null || uuidArray.length == 0) && uuid == null)
            return true;
        if (uuidArray == null)
            return false;
        for (ParcelUuid element: uuidArray) 
            if (element.equals(uuid)) return true;
        
        return false;
    
    /**
     * Returns true if there any common ParcelUuids in uuidA and uuidB.
     *
     * @param uuidA - List of ParcelUuids
     * @param uuidB - List of ParcelUuids
     *
     */
    public static boolean containsAnyUuid(ParcelUuid[] uuidA, ParcelUuid[] uuidB) 
        if (uuidA == null && uuidB == null) return true;
        if (uuidA == null) 
            return uuidB.length == 0 ? true : false;
        
        if (uuidB == null) 
            return uuidA.length == 0 ? true : false;
        
        HashSet<ParcelUuid> uuidSet = new HashSet<ParcelUuid> (Arrays.asList(uuidA));
        for (ParcelUuid uuid: uuidB) 
            if (uuidSet.contains(uuid)) return true;
        
        return false;
    
    /**
     * Returns true if all the ParcelUuids in ParcelUuidB are present in
     * ParcelUuidA
     *
     * @param uuidA - Array of ParcelUuidsA
     * @param uuidB - Array of ParcelUuidsB
     *
     */
    public static boolean containsAllUuids(ParcelUuid[] uuidA, ParcelUuid[] uuidB) 
        if (uuidA == null && uuidB == null) return true;
        if (uuidA == null) 
            return uuidB.length == 0 ? true : false;
        
        if (uuidB == null) return true;
        HashSet<ParcelUuid> uuidSet = new HashSet<ParcelUuid> (Arrays.asList(uuidA));
        for (ParcelUuid uuid: uuidB) 
            if (!uuidSet.contains(uuid)) return false;
        
        return true;
    
    /**
     * Extract the Service Identifier or the actual uuid from the Parcel Uuid.
     * For example, if 0000110B-0000-1000-8000-00805F9B34FB is the parcel Uuid,
     * this function will return 110B
     * @param parcelUuid
     * @return the service identifier.
     */
    public static int getServiceIdentifierFromParcelUuid(ParcelUuid parcelUuid) 
        UUID uuid = parcelUuid.getUuid();
        long value = (uuid.getMostSignificantBits() & 0x0000FFFF00000000L) >>> 32;
        return (int)value;
    
    /**
     * Parse UUID from bytes. The @code uuidBytes can represent a 16-bit, 32-bit or 128-bit UUID,
     * but the returned UUID is always in 128-bit format.
     * Note UUID is little endian in Bluetooth.
     *
     * @param uuidBytes Byte representation of uuid.
     * @return @link ParcelUuid parsed from bytes.
     * @throws IllegalArgumentException If the @code uuidBytes cannot be parsed.
     */
    public static ParcelUuid parseUuidFrom(byte[] uuidBytes) 
        if (uuidBytes == null) 
            throw new IllegalArgumentException("uuidBytes cannot be null");
        
        int length = uuidBytes.length;
        if (length != UUID_BYTES_16_BIT && length != UUID_BYTES_32_BIT &&
                length != UUID_BYTES_128_BIT) 
            throw new IllegalArgumentException("uuidBytes length invalid - " + length);
        
        // Construct a 128 bit UUID.
        if (length == UUID_BYTES_128_BIT) 
            ByteBuffer buf = ByteBuffer.wrap(uuidBytes).order(ByteOrder.LITTLE_ENDIAN);
            long msb = buf.getLong(8);
            long lsb = buf.getLong(0);
            return new ParcelUuid(new UUID(msb, lsb));
        
        // For 16 bit and 32 bit UUID we need to convert them to 128 bit value.
        // 128_bit_value = uuid * 2^96 + BASE_UUID
        long shortUuid;
        if (length == UUID_BYTES_16_BIT) 
            shortUuid = uuidBytes[0] & 0xFF;
            shortUuid += (uuidBytes[1] & 0xFF) << 8;
         else 
            shortUuid = uuidBytes[0] & 0xFF ;
            shortUuid += (uuidBytes[1] & 0xFF) << 8;
            shortUuid += (uuidBytes[2] & 0xFF) << 16;
            shortUuid += (uuidBytes[3] & 0xFF) << 24;
        
        long msb = BASE_UUID.getUuid().getMostSignificantBits() + (shortUuid << 32);
        long lsb = BASE_UUID.getUuid().getLeastSignificantBits();
        return new ParcelUuid(new UUID(msb, lsb));
    
    /**
     * Parse UUID to bytes. The returned value is shortest representation, a 16-bit, 32-bit or 128-bit UUID,
     * Note returned value is little endian (Bluetooth).
     *
     * @param uuid uuid to parse.
     * @return shortest representation of @code uuid as bytes.
     * @throws IllegalArgumentException If the @code uuid is null.
     */
    public static byte[] uuidToBytes(ParcelUuid uuid) 
        if (uuid == null) 
            throw new IllegalArgumentException("uuid cannot be null");
        
        if (is16BitUuid(uuid)) 
            byte[] uuidBytes = new byte[UUID_BYTES_16_BIT];
            int uuidVal = getServiceIdentifierFromParcelUuid(uuid);
            uuidBytes[0] = (byte)(uuidVal & 0xFF);
            uuidBytes[1] = (byte)((uuidVal & 0xFF00) >> 8);
            return uuidBytes;
        
        if (is32BitUuid(uuid)) 
            byte[] uuidBytes = new byte[UUID_BYTES_32_BIT];
            int uuidVal = getServiceIdentifierFromParcelUuid(uuid);
            uuidBytes[0] = (byte)(uuidVal & 0xFF);
            uuidBytes[1] = (byte)((uuidVal & 0xFF00) >> 8);
            uuidBytes[2] = (byte)((uuidVal & 0xFF0000) >> 16);
            uuidBytes[3] = (byte)((uuidVal & 0xFF000000) >> 24);
            return uuidBytes;
        
        // Construct a 128 bit UUID.
        long msb = uuid.getUuid().getMostSignificantBits();
        long lsb = uuid.getUuid().getLeastSignificantBits();
        byte[] uuidBytes = new byte[UUID_BYTES_128_BIT];
        ByteBuffer buf = ByteBuffer.wrap(uuidBytes).order(ByteOrder.LITTLE_ENDIAN);
        buf.putLong(8, msb);
        buf.putLong(0, lsb);
        return uuidBytes;
    
    /**
     * Check whether the given parcelUuid can be converted to 16 bit bluetooth uuid.
     *
     * @param parcelUuid
     * @return true if the parcelUuid can be converted to 16 bit uuid, false otherwise.
     */
    public static boolean is16BitUuid(ParcelUuid parcelUuid) 
        UUID uuid = parcelUuid.getUuid();
        if (uuid.getLeastSignificantBits() != BASE_UUID.getUuid().getLeastSignificantBits()) 
            return false;
        
        return ((uuid.getMostSignificantBits() & 0xFFFF0000FFFFFFFFL) == 0x1000L);
    
    /**
     * Check whether the given parcelUuid can be converted to 32 bit bluetooth uuid.
     *
     * @param parcelUuid
     * @return true if the parcelUuid can be converted to 32 bit uuid, false otherwise.
     */
    public static boolean is32BitUuid(ParcelUuid parcelUuid) 
        UUID uuid = parcelUuid.getUuid();
        if (uuid.getLeastSignificantBits() != BASE_UUID.getUuid().getLeastSignificantBits()) 
            return false;
        
        if (is16BitUuid(parcelUuid)) 
            return false;
        
        return ((uuid.getMostSignificantBits() & 0xFFFFFFFFL) == 0x1000L);
    

根据我的测试,结果完全符合我的要求。

【讨论】:

【参考方案7】:

您需要在广告数据中添加服务 UUID 作为link

那你可以重试startLeScan(UUID[],callback)。

我已经通过这种方法成功地发现了具有特定 UUID[0x1809] 的温度计设备

它确实对我有用。

【讨论】:

我有 0x03 《16 位服务类 UUID 的完整列表》,你有,我有 0x07 《128 位服务类 UUID 的完整列表》,还有你没有的。我想要的服务是 128 位服务,因此包含在 0x07 中。但感谢您确认,16 位 UUID 似乎可以工作。【参考方案8】:

我的经验是,我必须提供我想连接的设备所提供的每一项服务,而不仅仅是我关心的那个。为了解决这个问题,我最终在扫描后进行了服务发现。

【讨论】:

刚试过。如果我将设备提供的每项服务都放在其广告中,则在我的情况下不起作用。 (在我的情况下,它是一个 16 位和一个 128 位 UUID)【参考方案9】:

128 位 UUID LE 扫描适用于三星 S5,运行 Android 4.4.2;但是是的,它在 Nexus 4、7 上失败。在 4.4.2、4.4.3、4.4.4 上测试。

【讨论】:

【参考方案10】:

我在 Android 源代码 5.x 中发现了一个错误,但在 6.x 中不存在。

这个文件中有一个函数: http://androidxref.com/5.1.1_r6/xref/external/bluetooth/bluedroid/bta/dm/bta_dm_api.c#1560 用于将 32 位 data_mask 传递给蓝牙文件广告和扫描响应堆栈。 但是结构“tBTA_DM_API_SET_ADV_CONFIG;”管理 16 位长值! 所以将 UINT16 更改为 UINT32 或 data_mask,重新编译 Android 即可。 里夫 http://androidxref.com/5.1.1_r6/xref/external/bluetooth/bluedroid/bta/dm/bta_dm_int.h#594

【讨论】:

【参考方案11】:

我在使用我的 N7 2013 和 Android 4.3 的 TI 的 SensorTag 时遇到了同样的问题。

我发现工作是启动 LeScan,等待一秒钟,停止它然后重新启动它。

        if(!mBluetoothAdapter.startLeScan(mBleScanCallback))
            L.e("could not start scan action");
        
        try 
            Thread.sleep(1000);
         catch (InterruptedException e) 
        mBluetoothAdapter.stopLeScan(mBleScanCallback);
        try 
            Thread.sleep(1000);
         catch (InterruptedException e) 
        mBluetoothAdapter.startLeScan(mBleScanCallback);

我还注意到,有时连接未建立(这可能与固件实现或正确关闭连接有关,也可能无关)。以同样的方式,尝试重新连接到 gatt 似乎可以解决问题。

不得不使用这些变通办法真是令人失望......

【讨论】:

此问题讨论无法根据 API 过滤扫描结果。没有过滤器的扫描工作正常。我不确定您的答案是关于过滤还是仅扫描不带过滤器的 uuid。 在我的问题中查看我的编辑。你的回答不适用于我的问题。

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