BLE Central access GATT service from another device

[Leo Yang]

I'm using  ble_app_uart_c project in nRF5 SDK 17.1 with SES.

I got 2 different devices, one is ARC EM9D AIoT DK(as Peripheral) and another is nRF52840(as Central).

I was confused about how to access the Read/Write service from the GATT table.

I checked the functionality of ARC EM9D AIoT DK with "BLE Scanner" in my phone, as below.

I thought the functionality was very similar to ble_app_uart & ble_app_uart_c, so I changed the NUS_BASE_UUID in ble_nus_c.h as below.

My problem is the UUID of the service and R/W characteristics are not continuous in ARC EM9D AIoT DK, but it is continuous in nRF52840 as below.

So what part should I edit in ble_app_uart_c? Or is there any project fit my case?

Any advices will be highly appreciated.

If you need any other information, please let me know.

Thank you so much.

[Kenneth]

Hi,

Please check outmy reply here:
https://devzone.nordicsemi.com/f/nordic-q-a/85327/changing-14-15-octet-of-custom-base-uuid-instead-of-12-13-octet-at-the-sd_ble_uuid_vs_add-ble_uuid128_t-const-p_vs_uuid-uint8_t-p_uuid_type-fucnction-call/355813#355813 

Kenneth

[Leo Yang]

Hi Kenneth, Thanks for your reply.

I've read the reply you mentioned. It's about how to add BLE service, but that's not my problem.

Maybe I'm not clear.

I need a nRF52840 as a BLE central to access the GATT service as below.

I want to do things very similar to ble_app_uart_c project, but connected with another device.(ARC EM9D AIoT DK)

Please see the red checks above, the UUID of "CUSTOM SERVICE and CUSTOM CHARACTERISTIC"  is not consecutive. So only changing the NUS_BASE_UUID in ble_nus_c.h won't work.

Can you show me more detail about how to access the GATT services? API or other documents I should read.

Many thanks!

[Kenneth]

You are assuming that the bytes in questions need to be consecutive, there is no such requirement, you can set both base uuid and the 16bit UUID to service/characteristic to whatever you like.

Kenneth