Android GATT Services returns Null after many successful connection

Question

I am developing an Android app which connects to the BLE devices, Device does connect most of the time and i am able to capture the readings. But sometime after many connects disconnects, Bluetooth On/Off, my BluetoothGattCallback class method

onServicesDiscovered(BluetoothGatt gatt, int status)

with status 0 [which means GATT_SUCCESS].

now when i try to get the BluetoothGattService like:

BluetoothGattService service = gatt.getService(getServiceUUID());

it return null, so that i am unable to perform next steps. Please help me to find the problem.

If you can't understand, in what context question has been asked, please don't put your concern here. As i am seeing two users has downgrade this question. If you want more info about the ques, just ask and add comment. This type of behavior is not a professional outlook. So please maintain this. — jitain sharma, May 02 '14 at 07:33

score 4 · Accepted Answer · answered Mar 22 '16 at 07:41

You have to first discover all services for the given device, otherwise when you run BluetoothGattService service = gatt.getService(getServiceUUID()); it will return null.

I would recommend you add the onServicesDiscovered function and use gatt.discoverServices(); instead.

@Override
    // New services discovered
    public void onServicesDiscovered(BluetoothGatt gatt, int status) {
        if (status == BluetoothGatt.GATT_SUCCESS) {
            for (BluetoothGattService gattService : gattServices) {
                Log.i(TAG, "Service UUID Found: " + gattService.getUuid().toString());
            }
        }
    }

score 0 · Answer 2 · edited May 23 '17 at 12:32

0

hello because of bluetooth low energy is unstable . and as your question define that you get call back function with 0 status code. then instead of using getServivce(UUID). you can use getServices() method to discover avaliable services. this might be uuid issue!! Maybe you've got the UUID wrong..

edited May 23 '17 at 12:32

Community

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answered May 01 '14 at 16:34

mcd

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UUID is correct as i am able to get the services, but as i mention after 7 attempts of on/off BT or connect disconnect the device, both getService with UUID and getServices() returns null. – jitain sharma May 01 '14 at 16:40

Android GATT Services returns Null after many successful connection

2 Answers2