BleCharacteristicNotFoundException: Characteristic not found with UUID. How can I get the characteristic UUIDs from a Bluetooth device?

Question

I am unable to retrieve data from my device despite supplying what I believe to be the correct UUID: D/ERROR:: com.polidea.rxandroidble2.exceptions.BleCharacteristicNotFoundException: Characteristic not found with UUID 00001101-0000-1000-8000-00805f9b34fb. What should I do instead?

// Get device from scan
rxBleDevice = scanResult.bleDevice

val deviceUUID = UUID.fromString(scanResult.bleDevice.bluetoothDevice.uuids[0].toString())

// Check device info
println("Name: " + scanResult.bleDevice.name) // Prints to "TestDevice"
println("MAC Address: " + scanResult.bleDevice.macAddress) // Prints to "34:81:F4:3C:2D:7B"
println("UUID = $deviceUUID") // Prints to "00001101-0000-1000-8000-00805f9b34fb"
println("Service UUIDs = " + scanResult.scanRecord.serviceUuids) // Prints to "null"

/* Establish connection to device */
rxBleDevice!!.establishConnection(false) ?
 .doOnNext {
  _ ->
   Log.d("Device: ", "Connection Established")
 } ?
 .flatMapSingle {
  rxBleConnection ->
   deviceUUID? .let {
    rxBleConnection.readCharacteristic(it)
   }
 } ? .subscribe({
  count ->
  // count should be in bytes
  println("SUCCESS: $count")

 }, {
  throwable ->
  Log.d("ERROR: ", "$throwable")
 })

My expected output is a byte array that reads "datc00099", for example.

It seems that you know what value to expect on some characteristic. How do you know what to expect? — Dariusz Seweryn, Mar 28 '19 at 10:37
Have you asked them on what characteristic you should expect that value? — Dariusz Seweryn, Mar 28 '19 at 13:51
No I have not. Even if I did. How would I request that particular characteristic from the client? — Martin Erlic, Mar 28 '19 at 13:53
They should be able to give you the identifier (UUID) of characteristic you are looking for. From there it is as easy as use `rxBleConnection.readCharacteristic(UUID.fromString("stringGivenByPeripheralEngineer"))` — Dariusz Seweryn, Mar 28 '19 at 13:59

score 3 · Accepted Answer · edited Mar 30 '19 at 23:16

The UUID you try to use is from BluetoothDevice.getUuids() which seems to come from "classic" Bluetooth world.

scanResult.scanRecord.serviceUuids may also be null because the UUIDs are not guaranteed to be advertised. Bear in mind that service UUID and characteristic UUID, while having the same format, identify different attributes.

The easiest way to obtain the UUID you are looking for is to ask the peripheral's engineer.

Alternatively, if you know what you are searching for, you can connect to your peripheral, commence a service discovery and search through results. Using this lib in 1.9.0 version it would look like this:

rxBleClient.scanBleDevices(
    ScanSettings.Builder()
        .setScanMode(ScanSettings.SCAN_MODE_LOW_LATENCY)
        .build(),
    ScanFilter.Builder()
        .setDeviceName("TestDevice")
        .build()
)
    .take(1)
    .flatMap { it.bleDevice.establishConnection(false) }
    .flatMapSingle { it.discoverServices() }
    .take(1)
    .subscribe(
        { t -> t.bluetoothGattServices }, // Print services
        { Log.e("ERROR", "WHOOPS!", it) }
    )

Log options should be:

RxBleClient.updateLogOptions(LogOptions.Builder()
        .setLogLevel(LogConstants.VERBOSE)
        .setUuidsLogSetting(LogConstants.UUIDS_FULL)
        .build()

And in your logs you should see something like:

V/RxBle#ServiceDiscoveryOperation: Preparing services description
V/RxBle#ServiceDiscoveryOperation: --------------- ====== Printing peripheral content ====== ---------------
V/RxBle#ServiceDiscoveryOperation: MAC='XX:XX:XX:XX:XX:XX'
V/RxBle#ServiceDiscoveryOperation: PERIPHERAL NAME: SensorTag
V/RxBle#ServiceDiscoveryOperation: -------------------------------------------------------------------------
V/RxBle#ServiceDiscoveryOperation: Primary Service - Generic Access (00001800-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation: Instance ID: 1
V/RxBle#ServiceDiscoveryOperation: -> Characteristics:
V/RxBle#ServiceDiscoveryOperation:  * Device Name (00002a00-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ ]
V/RxBle#ServiceDiscoveryOperation:  * Appearance (00002a01-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ ]
V/RxBle#ServiceDiscoveryOperation:  * Peripheral Privacy Flag (00002a02-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ WRITE ]
V/RxBle#ServiceDiscoveryOperation:  * Reconnection Address (00002a03-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ WRITE ]
V/RxBle#ServiceDiscoveryOperation:  * Peripheral Preferred Connection Parameters (00002a04-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ ]
V/RxBle#ServiceDiscoveryOperation: Primary Service - Generic Attribute (00001801-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation: Instance ID: 12
V/RxBle#ServiceDiscoveryOperation: -> Characteristics:
V/RxBle#ServiceDiscoveryOperation:  * Service Changed (00002a05-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ INDICATE ]
V/RxBle#ServiceDiscoveryOperation:    -> Descriptors:
V/RxBle#ServiceDiscoveryOperation:      * Client Characteristic Configuration (00002902-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation: Primary Service - Device Information (0000180a-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation: Instance ID: 16
V/RxBle#ServiceDiscoveryOperation: -> Characteristics:
V/RxBle#ServiceDiscoveryOperation:  * System ID (00002a23-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ ]
V/RxBle#ServiceDiscoveryOperation:  * Model Number String (00002a24-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ ]
V/RxBle#ServiceDiscoveryOperation:  * Serial Number String (00002a25-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ ]
V/RxBle#ServiceDiscoveryOperation:  * Firmware Revision String (00002a26-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ ]
V/RxBle#ServiceDiscoveryOperation:  * Hardware Revision String (00002a27-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ ]
V/RxBle#ServiceDiscoveryOperation:  * Software Revision String (00002a28-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ ]
V/RxBle#ServiceDiscoveryOperation:  * Manufacturer Name String (00002a29-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ ]
V/RxBle#ServiceDiscoveryOperation:  * IEEE 11073-20601 Regulatory Certification Data List (00002a2a-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ ]
V/RxBle#ServiceDiscoveryOperation:  * PnP ID (00002a50-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ ]
V/RxBle#ServiceDiscoveryOperation: Primary Service - Unknown service (f000aa00-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation: Instance ID: 35
V/RxBle#ServiceDiscoveryOperation: -> Characteristics:
V/RxBle#ServiceDiscoveryOperation:  * Unknown characteristic (f000aa01-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ NOTIFY ]
V/RxBle#ServiceDiscoveryOperation:    -> Descriptors:
V/RxBle#ServiceDiscoveryOperation:      * Client Characteristic Configuration (00002902-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:      * Characteristic User Description (00002901-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:  * Unknown characteristic (f000aa02-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ WRITE ]
V/RxBle#ServiceDiscoveryOperation:    -> Descriptors:
V/RxBle#ServiceDiscoveryOperation:      * Characteristic User Description (00002901-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation: Primary Service - Unknown service (f000aa10-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation: Instance ID: 43
V/RxBle#ServiceDiscoveryOperation: -> Characteristics:
V/RxBle#ServiceDiscoveryOperation:  * Unknown characteristic (f000aa11-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ NOTIFY ]
V/RxBle#ServiceDiscoveryOperation:    -> Descriptors:
V/RxBle#ServiceDiscoveryOperation:      * Client Characteristic Configuration (00002902-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:      * Characteristic User Description (00002901-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:  * Unknown characteristic (f000aa12-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ WRITE ]
V/RxBle#ServiceDiscoveryOperation:    -> Descriptors:
V/RxBle#ServiceDiscoveryOperation:      * Characteristic User Description (00002901-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:  * Unknown characteristic (f000aa13-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ WRITE ]
V/RxBle#ServiceDiscoveryOperation:    -> Descriptors:
V/RxBle#ServiceDiscoveryOperation:      * Characteristic User Description (00002901-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation: Primary Service - Unknown service (f000aa20-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation: Instance ID: 54
V/RxBle#ServiceDiscoveryOperation: -> Characteristics:
V/RxBle#ServiceDiscoveryOperation:  * Unknown characteristic (f000aa21-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ NOTIFY ]
V/RxBle#ServiceDiscoveryOperation:    -> Descriptors:
V/RxBle#ServiceDiscoveryOperation:      * Client Characteristic Configuration (00002902-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:      * Characteristic User Description (00002901-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:  * Unknown characteristic (f000aa22-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ WRITE ]
V/RxBle#ServiceDiscoveryOperation:    -> Descriptors:
V/RxBle#ServiceDiscoveryOperation:      * Characteristic User Description (00002901-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation: Primary Service - Unknown service (f000aa30-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation: Instance ID: 62
V/RxBle#ServiceDiscoveryOperation: -> Characteristics:
V/RxBle#ServiceDiscoveryOperation:  * Unknown characteristic (f000aa31-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ NOTIFY ]
V/RxBle#ServiceDiscoveryOperation:    -> Descriptors:
V/RxBle#ServiceDiscoveryOperation:      * Client Characteristic Configuration (00002902-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:      * Characteristic User Description (00002901-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:  * Unknown characteristic (f000aa32-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ WRITE ]
V/RxBle#ServiceDiscoveryOperation:    -> Descriptors:
V/RxBle#ServiceDiscoveryOperation:      * Characteristic User Description (00002901-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:  * Unknown characteristic (f000aa33-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ WRITE ]
V/RxBle#ServiceDiscoveryOperation:    -> Descriptors:
V/RxBle#ServiceDiscoveryOperation:      * Characteristic User Description (00002901-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation: Primary Service - Unknown service (f000aa40-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation: Instance ID: 73
V/RxBle#ServiceDiscoveryOperation: -> Characteristics:
V/RxBle#ServiceDiscoveryOperation:  * Unknown characteristic (f000aa41-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ NOTIFY ]
V/RxBle#ServiceDiscoveryOperation:    -> Descriptors:
V/RxBle#ServiceDiscoveryOperation:      * Client Characteristic Configuration (00002902-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:      * Characteristic User Description (00002901-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:  * Unknown characteristic (f000aa42-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ WRITE ]
V/RxBle#ServiceDiscoveryOperation:    -> Descriptors:
V/RxBle#ServiceDiscoveryOperation:      * Characteristic User Description (00002901-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:  * Unknown characteristic (f000aa43-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ ]
V/RxBle#ServiceDiscoveryOperation:    -> Descriptors:
V/RxBle#ServiceDiscoveryOperation:      * Client Characteristic Configuration (00002902-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:      * Characteristic User Description (00002901-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation: Primary Service - Unknown service (f000aa50-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation: Instance ID: 85
V/RxBle#ServiceDiscoveryOperation: -> Characteristics:
V/RxBle#ServiceDiscoveryOperation:  * Unknown characteristic (f000aa51-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ NOTIFY ]
V/RxBle#ServiceDiscoveryOperation:    -> Descriptors:
V/RxBle#ServiceDiscoveryOperation:      * Client Characteristic Configuration (00002902-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:      * Characteristic User Description (00002901-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:  * Unknown characteristic (f000aa52-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ WRITE ]
V/RxBle#ServiceDiscoveryOperation:    -> Descriptors:
V/RxBle#ServiceDiscoveryOperation:      * Characteristic User Description (00002901-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation: Primary Service - Unknown service (0000ffe0-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation: Instance ID: 93
V/RxBle#ServiceDiscoveryOperation: -> Characteristics:
V/RxBle#ServiceDiscoveryOperation:  * Unknown characteristic (0000ffe1-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ NOTIFY ]
V/RxBle#ServiceDiscoveryOperation:    -> Descriptors:
V/RxBle#ServiceDiscoveryOperation:      * Client Characteristic Configuration (00002902-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:      * Characteristic User Description (00002901-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation: Primary Service - Unknown service (f000aa60-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation: Instance ID: 98
V/RxBle#ServiceDiscoveryOperation: -> Characteristics:
V/RxBle#ServiceDiscoveryOperation:  * Unknown characteristic (f000aa61-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ ]
V/RxBle#ServiceDiscoveryOperation:    -> Descriptors:
V/RxBle#ServiceDiscoveryOperation:      * Characteristic User Description (00002901-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:  * Unknown characteristic (f000aa62-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ WRITE ]
V/RxBle#ServiceDiscoveryOperation:    -> Descriptors:
V/RxBle#ServiceDiscoveryOperation:      * Characteristic User Description (00002901-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation: Primary Service - Unknown service (f000ccc0-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation: Instance ID: 105
V/RxBle#ServiceDiscoveryOperation: -> Characteristics:
V/RxBle#ServiceDiscoveryOperation:  * Unknown characteristic (f000ccc1-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ READ NOTIFY ]
V/RxBle#ServiceDiscoveryOperation:    -> Descriptors:
V/RxBle#ServiceDiscoveryOperation:      * Client Characteristic Configuration (00002902-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:      * Characteristic User Description (00002901-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:  * Unknown characteristic (f000ccc2-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ WRITE ]
V/RxBle#ServiceDiscoveryOperation:    -> Descriptors:
V/RxBle#ServiceDiscoveryOperation:      * Characteristic User Description (00002901-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:  * Unknown characteristic (f000ccc3-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ WRITE ]
V/RxBle#ServiceDiscoveryOperation:    -> Descriptors:
V/RxBle#ServiceDiscoveryOperation:      * Characteristic User Description (00002901-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation: Primary Service - Unknown service (f000ffc0-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation: Instance ID: 116
V/RxBle#ServiceDiscoveryOperation: -> Characteristics:
V/RxBle#ServiceDiscoveryOperation:  * Unknown characteristic (f000ffc1-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ WRITE_NO_RESPONSE WRITE NOTIFY ]
V/RxBle#ServiceDiscoveryOperation:    -> Descriptors:
V/RxBle#ServiceDiscoveryOperation:      * Client Characteristic Configuration (00002902-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:      * Characteristic User Description (00002901-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:  * Unknown characteristic (f000ffc2-0451-4000-b000-000000000000)
V/RxBle#ServiceDiscoveryOperation:    Properties: [ WRITE_NO_RESPONSE WRITE NOTIFY ]
V/RxBle#ServiceDiscoveryOperation:    -> Descriptors:
V/RxBle#ServiceDiscoveryOperation:      * Client Characteristic Configuration (00002902-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation:      * Characteristic User Description (00002901-0000-1000-8000-00805f9b34fb)
V/RxBle#ServiceDiscoveryOperation: --------------- ====== Finished peripheral content ====== ---------------

Characteristic UUIDs are provided in brackets. You would just need to find the one you are looking for.

Thanks for the great feedback! I'll investigate this shortly. The engineer actually just told me the following ``I just tried the Microchip configuration tool for the BlueTooth module in the device and the file that loads to the module shows BT3.0 UUID 0x0000. It's an editable field so you should be able to change it to whatever you need.`` Does this mean the characteristic UUID is standard? Would you be able to guess what it is from this information alone? — Martin Erlic, Mar 28 '19 at 17:59
This is all the information I can get from the device that I want with those Log settings: ``I/RxBle#Client: ScanResult{bleDevice=RxBleDeviceImpl{MAC='XX:XX:XX:XX:XX:XX', name=myDevice}, rssi=-47, timestampNanos=510459619150822, callbackType=CALLBACK_TYPE_ALL_MATCHES, scanRecord=[...]}`` — Martin Erlic, Mar 28 '19 at 19:25
`BT3.0` could indicate that this is not a BLE device (which started at `BT4.0`). I do not know Microchip toolchain to say more at this moment. You can adjust the code above so the `ScanFilter` would match your device and the discovered services should be logged. So you could then check if there is characteristic that you need — Dariusz Seweryn, Mar 29 '19 at 10:12
This is the board and I'm using, which supports the Bluetooth 4.2 protocol: https://www.mouser.ca/ProductDetail/Microchip/BM78SPPS5NC2-0002AA?qs=8cKuZ6Ok2lYrZ%2Fl1HnN6jQ==&gclid=Cj0KCQjwhPfkBRD0ARIsAAcYycGMS9pxOBNygel1rVdBQzq1it-RfzLB4cJjBEr-sC0ZfMJhLca8EyAaAnPZEALw_wcB. — Martin Erlic, Mar 29 '19 at 21:16
It is a dual mode device then. Still it is not sure what protocol version is used. If you would connect, perform a service discovery as mentioned in the post it should be possible to guess something more. — Dariusz Seweryn, Mar 29 '19 at 22:38
Thanks. I added the remaining log filters you recommended. Here is a gist with the available services: https://gist.github.com/SeloSlav/ec7fbfd8e333c3405b5340c41d2bdd4d. — Martin Erlic, Mar 30 '19 at 00:49
There are 5 unknown characteristic there 4 of which may be potentially interesting for you. None of them is using a `UUID` that has `0x0000` part though. This may point that you want to use this peripheral in so called Bluetooth Classic mode. If this is the case `RxAndroidBle` library will not help you as it is a Low Energy library only. Anyway it is unusual that the engineer was not able to give you information on whether you should use classic or low energy protocol — Dariusz Seweryn, Mar 30 '19 at 09:41
I was finally able to retrieve a value by trial and error. Only one UUID worked and it returned ``[B@92281af``. — Martin Erlic, Mar 30 '19 at 23:11
`[B@92281af` looks like a result of `byte[]` `.toString()` function. To see the actual values use `Arrays.toString(byte[])` which will print the bytes as integers — Dariusz Seweryn, Mar 31 '19 at 07:45

BleCharacteristicNotFoundException: Characteristic not found with UUID. How can I get the characteristic UUIDs from a Bluetooth device?

1 Answers1