How could I use NUS without service discover?

RE: How could I use NUS without service discover?

FormerMember — Wed, 04 May 2016 10:58:02 GMT

Great.

I will not change the sd_ble_gatts_service_add() sequence in my project. In this case, the handle value will be always the same.

And I will try to add bonding and caching scenario to follow proper way.

Thanks

RE: How could I use NUS without service discover?

Petter Myhre — Wed, 04 May 2016 10:45:01 GMT

Searching and connection is done within 2 second. but Service Discover is too long, it takes a over 5 seconds. I think,I need not discover the service because I already know the service which I use - NUS. And Service Discover tell me only the cccd, rx, tx handle.

The proper way to avoid doing service discovery on every connection is to cache attributes, but then you should be bonded. If you are using the Device Manager please see this for more information. If you are using the Peer Manager, you can see from the documentation that it is capable of caching GATT attributes.

But I cannot find where this value is made? Is this value is fixed for all device ?

The server on the peripheral has an attribute table with attribute handles. What attibute handle an attribute (service/characteristic/descriptor) is assigned depends on the order it is added to the attribute table. So if you for example add hrs and nus, nus will get different attribute handles depending if you add it before or after hrs. When you add nus the attribute handle is returned sd_ble_gatts_service_add(BLE_GATTS_SRVC_TYPE_PRIMARY, &ble_uuid, &p_nus->service_handle);

RE: How could I use NUS without service discover?

FormerMember — Wed, 04 May 2016 07:58:49 GMT

Thanks for your help.

Actually I have test as your suggest. fixed hanlde. it works. I want to know how could I get the fixed handle. I can get it by some test, but I can't findout why this handle is fixed. Could you tell me where I can find out NUS's rx,tx,cccd?

RE: How could I use NUS without service discover?

Milan — Wed, 04 May 2016 05:07:48 GMT

Hi,

I think this will help.

Regards,

Milan Joshi