BLE Central - The Service and Characteristics have different base UUID

RE: BLE Central - The Service and Characteristics have different base UUID

Marjeris Romero — Mon, 28 Oct 2019 14:22:42 GMT

Hi,

I am so sorry but can you please explain a bit better what are you trying to do and what the problem is? I don't quite understand what you want to achieve right now.

We have a tutorial about Bluetooth central devices, which is unfortunately a little updated but may still be helpful for you, I recommend you take a look at it.

Best regards,

Marjeris

RE: BLE Central - The Service and Characteristics have different base UUID

Gaht — Fri, 25 Oct 2019 12:45:46 GMT

I found the solution. In main.c, I changed the type
NUS_SERVICE_UUID_TYPE = BLE_UUID_TYPE_VENDOR_BEGIN + the number of base UUID that I wanna add)

And I can scan my BLE Peripheral.

For instance, I wanna add 3 UUID more. So I modified the the NUS_SERVICE_UUID_TYPE = BLE_UUID_TYPE_VENDOR_BEGIN +3;

But I am curious and have a question: Does the final base UUID that I add must belong to Service?
because when I add it first, It can not discover my characteristics. Is it relate to ble_db_discovery_evt_register() function?

Sorry for my English, it may be not clear :(

RE: BLE Central - The Service and Characteristics have different base UUID

Gaht — Fri, 25 Oct 2019 01:30:52 GMT

Hi Msromero,
Thanks for your comment and sorry for my question lack information and that causes you misunderstood my question.

Instead of coding the BLE Peripheral, I must code the BLE Central to take data from it.
You can see the picture I post above that its Service has differents base UUID from Characteristics ( I use nRF Connect app in my Smartphone connect to the BLE Peripheral).

My question is why I can not scan the BLE Peripheral when I add some base UUIDs in the BLE Central? ( I use NRF52832 board, SDK15.2, s132, and the ble_app_uart_c example).

RE: BLE Central - The Service and Characteristics have different base UUID

Marjeris Romero — Thu, 24 Oct 2019 10:59:25 GMT

Hi,

Do you have a requirement for different base UUIDs in your project? What is usually recommended is to use a 128-bit vendor specific UUID which will look something like this "4A98xxxx-1CC4-E7C1-C757-F1267DD021E8" as a “base UUID”. The four x’s represent a field where you will insert your own 16-bit IDs for your custom services and characteristics and use them just like a predefined UUID. You will have different customs UUID for each service and characteristic but only one "base UUID".

Take a look at our Service tutorial and also this Custom BLE service example if you want a step by step guide of how to make your own custom service including vendor specific UUIDs.

Best regards,

Marjeris