Android BluetoothGATT discoverServices() delivers a lot of services

1
votes

After connecting to a specific ScanResult like this

bluetoothGatt = scanResult.getDevice().connectGatt(getActivity(), false, new MyBluetoothGattCallback());

I call Androids BluetoothGatt.discoverServices() method and in BluetoothGattCallback.onServicesDiscovered() I call getServices() on BluetoothGatt.

When I list the services and the regarding characteristics I get a lot more what I expect. It should be 1 service with 1 characteristic at this Peripheral simulated with LightBlue on the iPad, but there are a lot more services.. take a look into my log:

MyBluetoothGattCallback﹕ service: 00001800-0000-1000-8000-00805f9b34fb MyBluetoothGattCallback﹕ characteristic: 00002a00-0000-1000-8000-00805f9b34fb MyBluetoothGattCallback﹕ characteristic: 00002a01-0000-1000-8000-00805f9b34fb MyBluetoothGattCallback﹕ service: 00001801-0000-1000-8000-00805f9b34fb MyBluetoothGattCallback﹕ characteristic: 00002a05-0000-1000-8000-00805f9b34fb MyBluetoothGattCallback﹕ service: d0611e78-bbb4-4591-a5f8-487910ae4366 MyBluetoothGattCallback﹕ characteristic: 8667556c-9a37-4c91-84ed-54ee27d90049 MyBluetoothGattCallback﹕ service: 7905f431-b5ce-4e99-a40f-4b1e122d00d0 MyBluetoothGattCallback﹕ characteristic: 69d1d8f3-45e1-49a8-9821-9bbdfdaad9d9 MyBluetoothGattCallback﹕ characteristic: 9fbf120d-6301-42d9-8c58-25e699a21dbd MyBluetoothGattCallback﹕ characteristic: 22eac6e9-24d6-4bb5-be44-b36ace7c7bfb MyBluetoothGattCallback﹕ service: 0000180f-0000-1000-8000-00805f9b34fb MyBluetoothGattCallback﹕ characteristic: 00002a19-0000-1000-8000-00805f9b34fb MyBluetoothGattCallback﹕ service: 00001805-0000-1000-8000-00805f9b34fb MyBluetoothGattCallback﹕ characteristic: 00002a2b-0000-1000-8000-00805f9b34fb MyBluetoothGattCallback﹕ characteristic: 00002a0f-0000-1000-8000-00805f9b34fb MyBluetoothGattCallback﹕ service: 89d3502b-0f36-433a-8ef4-c502ad55f8dc MyBluetoothGattCallback﹕ characteristic: 9b3c81d8-57b1-4a8a-b8df-0e56f7ca51c2 MyBluetoothGattCallback﹕ characteristic: 2f7cabce-808d-411f-9a0c-bb92ba96c102 MyBluetoothGattCallback﹕ characteristic: c6b2f38c-23ab-46d8-a6ab-a3a870bbd5d7 MyBluetoothGattCallback﹕ service: 00001111-0000-1000-8000-00805f9b34fb MyBluetoothGattCallback﹕ characteristic: 00002222-0000-1000-8000-00805f9b34fb

Could somebody explain me why I get so much services there? Is there something with caching?

2
androidbluetooth-lowenergygatt

2 Answers

0
votes

You are seeing the BLE services that iOS advertises (e.g. GAP, GATT, device, battery, time and Apple custom UUID(s)) in addition to your own.

The standard BLE profiles follow this 128bit UUID format: 0000xxxx-0000-1000-8000-00805f9b34fb

The xxxx values are the 16-bit UUID that appear in the 'AssignedNumber' column on this list:

https://developer.bluetooth.org/gatt/services/Pages/ServicesHome.aspx?_ga=1.155151483.2108676045.1455359849

Regards Wayne

0
votes

Keep in mind that your peripheral device typically will have built in services and characteristics that were not necessarily defined by you. For example, the Arduino Nano 33 BLE that I am utilizing for my project has two additional services that are included in addition to the one that I had defined.