Discovering problem for different 128-bit service and characteristic uuid as a central device

[secondbest]

Hello;

I am using NRF51822 with SDK12.3 as a central device. I want to discover and connect a peripheral bluetooth device by using my NRF51822 central device.

If the service and characteristic is the same, for example service uuid is "00002234-b38d-4985-720e-0f993a68ee41" and characteristic uuid is "00002235-b38d-4985-720e-0f993a68ee41" , I can enable the notification of the characteristic and NRF51 get data from this peripheral device by using this characteristic.

However, If the service and characteristic is the different, for example service uuid is "680c21d9-c946-4c1f-9c11-baa1c21329e7" and characteristic uuid is "003bbdf2-c634-4b3d-ab56-7ec889b89a37", I can connect to this device but NRF51 discovers all characteristics as 0x00 and cannot enable the notification.

Is there a way to handle this problem?

Thanks.

[Jim_huan]

Hi,

Now I just doing the same project like this, and how about your progress now?And Can I  get some advices form you ?thx.

[secondbest]

Hello Jim_huan, in my experience, it is not possible to scan different service and characteristic addresses as a central device. On the other hand, it is possible to create different service and characteristic addresses as a peripheral device.

[Bjørn Kvaale]

Hi secondbest,

Could you please explain what you mean by it not being possible to scan different service & characteristic addresses as a central device?

I would recommend to take a close look at the ble_nus_c_init() function & the ble_db_discovery_evt_register() function from the uart central application in sdk 12.3.

[secondbest]

Hi Bjorn Kvaale. First of all, sorry for my bad english. I sometimes may not be able to say exactly what I mean. I try to explain again. In our exprience. We have an DWM1001 sensor. I did not create this sensor code. It comes with a ready code inside. In this DWM1001 module, there are service and characteristic like this:

Service: "680c21d9-c946-4c1f-9c11-baa1c21329e7"

Characteristic of this service: "003bbdf2-c634-4b3d-ab56-7ec889b89a37"

And, I create a central device with NRF51822 to connect this DWM1001 module. My NRF51822 code (central device) can connect to this DWM1001 sensor by using BLE without any error. However, my central device cannot get data from dwm1001 sensor characteristic ("003bbdf2-c634-4b3d-ab56-7ec889b89a37").

You can try this situation by creating a peripheral device that has different service and characteristic address. 

Also, we terminated this project and I write our own DWM1001 code. I just write this to help people who will searh it in later.

Thank you very much for your patience and your continued help.