How to scan for peripherals that have a given service UUID as a key in their service data?

I’m trying to scan for peripherals that advertise a key-value pair in their service data where the key is a given service UUID and the value is a unique identifier, different for each peripheral. Those peripherals only use serviceData, they do not advertise the service UUID in serviceUuids.

Here is what I tried so far:

AsyncTask.execute {
       val scannedBleServices = mapOf(
            "ABC" to ParcelUuid(UUID.fromString("00001234-5678-9012-3456-789012345678"))
       )
       val scanFilters = scannedBleServices.values.map {
           ScanFilter.Builder().setServiceData(it, ByteArray(0)).build()
       }
       val scanSettings = ScanSettings.Builder()
                .setLegacy(false)
                .setScanMode(ScanSettings.SCAN_MODE_LOW_LATENCY)
                .setReportDelay(0L)
                .setCallbackType(ScanSettings.CALLBACK_TYPE_ALL_MATCHES)
                .setMatchMode(ScanSettings.MATCH_MODE_AGGRESSIVE)
                .setNumOfMatches(ScanSettings.MATCH_NUM_ONE_ADVERTISEMENT)
                .build()
        BluetoothLeScannerCompat.getScanner().startScan(
                scanFilters,
                scanSettings,
                leScanCallback
        )
}

But with that, the callback is never called. Note that if I pass null as a first parameter to startScan, my callback does get called, which seems to indicate that I have all the permissions working properly, and I have just a problem with my filters.

[philips77]

As a matter of fact, on iOS, I’m able to set a filter on serviceUUID and my peripherals show up in the background even if I’m only advertising this service UUID in serviceData apparently.

Oh, good to know. Did you try setting setUseHardwareFilteringIfSupported(false) and see the difference? Is it an issue in the library or just the system does not filter well? https://github.com/NordicSemiconductor/Android-Scanner-Compat-Library/blob/8df7799441def4db80b7c9055ff99ecb57d9dad3/scanner/src/main/java/no/nordicsemi/android/support/v18/scanner/ScanSettings.java#L511

[sarbogast]

The phone I’m testing with is pretty standard and modern: Samsung Galaxy S9. So if that’s what it takes for it to work, I don’t see a lot of other choices.