Android: Read characteristic without service discovery

[PVS]

We are writing an Android app for our own peripheral (nRF51-based). We know the handles for all the characteristics.

On Android gatt.discoverServices() needs to be called, and wait for onServicesDiscovered(), then getServices(), before the Characteristic object is available.

This is very time-consuming, and often onServicesDiscovered() does not get called (despite connection success).

Is there a way to directly to write to an attribute handle or a characteristic UUID, bypassing all the discovery steps?

[Hung Bui]

No, as far as I know.

How often do you have the issue "often onServicesDiscovered() does not get called" ? Do you see that when you use our nRFConnect app ?

[Aleksander Nowakowski]

To avoid this problem:

• make sure the nRF Connect is closed with Back button
• disable GATT Server, or switch the option mentioned above to OFF
• wait for ~2 sec before calling discoverServices(). In this time nRF should be ready and you should get services from cache immediately.