Accessing different services with pc-ble driver

RE: Accessing different services with pc-ble driver

Kampino — Wed, 29 Jun 2022 11:14:32 GMT

thank you. I´ve got it now 🙂

RE: Accessing different services with pc-ble driver

Hung Bui — Tue, 28 Jun 2022 14:31:59 GMT

I assume you are trying to do is to do generic service discovery. Very similar to what our nRF Connect BLE app is doing.
I would suggest to have a look at this discussion here: custom service discovery in BLE_Central

It's about 4 years old but still relevant I think.

After you receive the services, you would also receive the uuid and the handle_range of the services. Based on the range, you can start doing your characteristic discovery.

I would suggest to have a look at our ble_db_discovery.c as the reference.

RE: Accessing different services with pc-ble driver

Kampino — Tue, 28 Jun 2022 13:11:32 GMT

Hi Hung Bui

thanks. I figured it out today after I found the sequence chart. The application is finding all services now, but I have a new problem.

I try to build up a tree view with all the services and all the characteristics. I got all the services already, but I need the characteristics for each service too

I also get the characteristics from "sd_ble_gattc_characteristics_discover". Is there a way to figure out which characteristic is from which service?

RE: Accessing different services with pc-ble driver

Hung Bui — Tue, 28 Jun 2022 12:00:12 GMT

Hi Daniel,
As far as I know the application need to call sd_ble_gattc_primary_services_discover() again and again until you receive the BLE_GATTC_EVT_PRIM_SRVC_DISC_RSP event with ATTRIBUTE_NOT_FOUND.

Please have a look at this sequence chart here: https://infocenter.nordicsemi.com/topic/com.nordic.infocenter.s132.api.v7.3.0/group___b_l_e___g_a_t_t_c___p_r_i_m___s_r_v_c___d_i_s_c___m_s_c.html?cp=4_7_3_1_2_2_3_10

RE: Accessing different services with pc-ble driver

Kampino — Mon, 27 Jun 2022 16:40:35 GMT

Hi Hung Bui ,

yes I have checked it and it helps. But I´m looking for a more generic way to discover all services without letting the application know how many services it should discover. Is there a way to iterate through

sd_ble_gattc_primary_services_discover

until all services are discovered? How can I get feedback that the application doesn´t have discovered all services? I´m missing how I can implement the handling of different services with the pc-ble-driver. Is there an example how to do it?

RE: Accessing different services with pc-ble driver

Hung Bui — Mon, 27 Jun 2022 15:10:18 GMT

Hi Daniel,
As mentioned here. If you haven't got all the primary service you need to call sd_ble_gattc_primary_services_discover() again. Have you tried that ?

RE: Accessing different services with pc-ble driver

Kampino — Mon, 20 Jun 2022 07:36:18 GMT

Hi Hung Bui ,

sorry for the late response. I didn´t have checked the update...

I don´t test the example, because I have to port the example to Qt and I don´t have the patience to do it till now. But I have checked the examples and tried to use them as a base for my code.

I have appended the BLE class file to my answer. Please take a look at it. It is based on the examples from the pc-ble-driver. The service discovery ends in on_Service_Discovery_Response.

devzone.nordicsemi.com/.../qt_5F00_ble.cpp

RE: Accessing different services with pc-ble driver

Hung Bui — Fri, 17 Jun 2022 11:42:13 GMT

Hi Daniel,

Could you let me know how did you do service discovery ?
Have you tried to test with our heart_rate_collector example in examples folder in pc-ble-driver?

Notice how the BLE_UUID_HEART_RATE_SERVICE is added to sd_ble_gattc_primary_services_discover() call inside service_discovery_start().