Accessing different services with pc-ble driver

[Kampino]

Hello,

I try to connect a BLE application with my PC by using an nRF52840 dongle and the PC-BLE driver. But I got stuck in the understanding of the driver, so I hope that someone can help me.

The ESP32 provides two additional services: 

• A device information service
• A battery service

I run a modified version of the BLE driver from a Qt application and the service discovery outputs three services

"Received service discovery response. Service count: 3"
" Service UUID: 0x1800"
" Service UUID: 0x1801"
" Service UUID: 0x180a"

But where is the fourth service? I only got the two common services and the device information service, but the battery service is missing.

How can I use multiple services with the BLE driver? I have figured out that I can store the handles of each service by looping through each service after the discovery. And I assume that I have to use each handle to access a discovered service?

And I´m looking for an example for reading / writing some values from the characteristics of a given service. Do you have an example?

Thank you for your help

[Kampino]

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?

[Hung Bui]

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. 

[Kampino]

Hi Hung Bui 

thank you. I´ve got it now