Bluetooth LE discover all GATT services

By Martin Woolley

19 Jan 2016 01:06 English 6 Replies

I would like to discover all the GATT services a Bluetooth LE device my mobile app has connected to "contains". I cannot see the API which would allow me to do this. The uuids property of BluetoothLEDevice seems to contain only UUIDs which were included in the advertising packet. I need *all* services the device profile includes. This is a standard procedure when working with Bluetooth LE devices.

Thanks

function onConnected() {
console.log("Connected to device");
// NB at this point all we have are the UUIDs included in the ADV packet.
var uuids = selected_device.uuids;
var services = "";
for (var i = 0; i < uuids.length; i++) {
services += uuids[i] + "\n";
}
console.log ("Service found: " + services);
}

Edited by: Martin Woolley on 19 Jan, 2016

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6 Replies

daniel kim

19 Jan 2016 22:59

Hi,

I would suggest you to check this code from SDK help page.

function showGATTService(service, indent)
{
   if (indent === undefined)
   {
      indent = "";
   }

console.log(indent + "Service " + service.uuid + ". Has " + service.characteristics.length
+ " characteristics and " + service.services.length + " sub-services.");

   for (var i = 0; i < service.services.length; i++)
   {
      showGATTService(service.services[i], indent + "   ");
   }
}

var serviceUUIDs = remoteDevice.uuids;

var i = 0, service = null;

for (i; i < serviceUUIDs.length; i++)
{

service = remoteDevice.getService(serviceUUIDs[i]);

showGATTService(service);
}

Hope this will help you.

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Martin Woolley

19 Jan 2016 23:44

Thanks Daniel but I don't think this helps. If I understand the code correctly it lets you "show" a primary service and each of the secondary services it contains (by recursion). You need to know a service UUID before you can call it. I'm looking for a function which will discover all services from a connected device. Android (and every other smartphone platform I know) supports this as service discovery is a basic Bluetooth LE operation. See Android's BluetoothGatt class and its discoverServices() method for example.

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Aditya Aswani Martin Woolley

20 Jan 2016 21:43

var serviceUUIDs = remoteDevice.uuids

I suppose once connected to the remote device "remoteDevice.uuids" will give an exhaustive list of services present with the remote device , not just the services in the ADV.

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Martin Woolley Aditya Aswani

22 Jan 2016 00:45

Hi Aditya

according to my testing, the content of the remoteDevice.uuids property does not change when you connect. There's no evidence of an automatic service/characteristic/discovery process going on.

I have a protocol analyser so maybe I'll verify this with some tracing. Right now it just looks like Tizen doesn't support this essential use case.