Some custom characteristic cannot be found

[jorenaku]

I am trying to using nRF52833 and nRF52840 as a BLE central to connect customer's BLE peripheral.

The attached screenshot is the service discovered by nRF connect Android App.

There are two characteristics in the service dc03900d-7c54-44fa-bca6-c61732a248ef

1. Uuid: b77acfa5-8f26-4af6-815b-74d03b4542c5
2. Uuid: 6dfe5997-fd7b-4e31-a609-c2af9cba78cf

However, nRF52833 and nRF52840 can only fond one characteristic b77acfa5-8f26-4af6-815b-74d03b4542c5.
I used the cli command on the ble_app_interactive example to check the characteristic result.
The result shows that it cannot find the characteristic 6dfe5997-fd7b-4e31-a609-c2af9cba78cf.

 

Why the characteristic 6dfe5997-fd7b-4e31-a609-c2af9cba78cf cannot be discovered by nRF52833/nRF52840?

Thanks a lot

[Einar Thorsrud]

Hi,

jorenaku said:

But since I’m not so familiar with BLE spec, I’m not sure if this modify may cause any other side effect.
Could you help double confirm this solution for me?

I do not immediately see that it is a problem, but I also am not sure why you need to do this. I am wondering if the problem here is how you configure the discovery module rather than the discovery module itself. Can you share your code so that I see how you have done this? (please du not use images but rather share the code as text using either Insert -> Image/Video/File or by copy pasting into Insert -> Code, as that makes it easier to read and search.)

jorenaku said:

And according to the BLE spec, should the characteristic discovery should found the next attribute value or next characteristic value? 

I am not sure what you refer to by attribute value in this context? Everything are attributes, both services, characteristics and descriptors. But there is a hierarchy, so you will have services, and under each service you have one or more characteristics, which has zero or more descriptors. And that is the order you will discover them as well. See A Developer’s Guide To Bluetooth.