startLeScan with 128 bit UUIDs doesn't work on native Android BLE implementation

Question

I am having trouble using startLeScan( new UUID[]{ MY_DESIRED_128_BIT_SERVICE_UUID }, callback ) on the new introduced BLE API of Android 4.3 on my Nexus 4.

The cal

Answer 1

I've found a bug in Android source 5.x, but not present in 6.x.

There a function in this file: http://androidxref.com/5.1.1_r6/xref/external/bluetooth/bluedroid/bta/dm/bta_dm_api.c#1560 used to pass a 32 bit data_mask to bluetooth le advertising and scan response stack. But the structure "tBTA_DM_API_SET_ADV_CONFIG;" manage 16 bit long value !!! So change UINT16 to UINT32 dor data_mask, recompile Android and it will works. Rif http://androidxref.com/5.1.1_r6/xref/external/bluetooth/bluedroid/bta/dm/bta_dm_int.h#594

Answer 2

You need add service UUID in the advertisement data as the link

Then you can try again startLeScan (UUID[],callback).

I had succeed by this method to discovery thermometer device with specific UUID[0x1809]

It does work for me.

Answer 3

@Navin's code is good, but it includes an overflow bug from the original 16-bit Android code. (If either byte is larger than 127 then it becomes a negative integer.)

Here's an implementation which fixes that bug and adds 128-bit support:

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;
 }

Answer 4

Are you certain that the peripheral is listing the specified service UUID in the advertisement data or scan response data?

Answer 5

My experience is that I had to supply EVERY service that a device I want to connect to presents, not just the one I am concerned with. I ended up doing service discovery after scan to get around this.