RE: Vendor Specific UUID Type/s

Einar Thorsrud — Tue, 08 Oct 2024 13:28:48 GMT

Hi,

[quote user=""]Who is deciding these TYPE values and how?[/quote]

This is a number assigned when you configure the base UUID as allready desscribed.

[quote user=""]If Central's SoftDevice is populating it, will those be same every time when we try to retrieve the services and characteristics from the same peripheral connects/reconnects?[/quote]

Yes. If the order where you confiugre the base UUID by calling sd_ble_uuid_vs_add() is the same, the type will always be the same. Note that the type is an internal reference to a base UUID. The type itself is not visible outside (to the peer).

[quote user=""]Is there any way to use only particular TYPE common across all our vendor specific services and characteristics?[/quote]

If all your vendor specific services has the same base UUID, then yes, you can use the same type. In that case you only need one call to sd_ble_uuid_vs_add() to confiugre the base UUID and get the type, and then refer to that type for adding all the services that use that base UUID in case of a GATT server or discoverying UUIDs using it in case of a GATT client (as in your case).

[quote user=""]Will those keep on incrementing if we add more peripherals or same for every peripheral identified by connection handle?[/quote]

This way of refering to a base UUID is the same regardless.

RE: Vendor Specific UUID Type/s

Turbo J — Tue, 08 Oct 2024 09:38:53 GMT

> Who is deciding these TYPE values and how?

Check softdevice specs/api, there is a call to add custom UUIDs to the softdevice memory. You will get new TYPE values when registering UUIDs - the only predefined one ist from the Bluetooth standard.

For your own devices you will need to register just one custom 128-bit UUID and then just change the 16 bits that correspond to the uuid part in ble_uuid_t when defining services and characteristics.

Not that this applies only to the old SDK thats no longer supported. Consider switching to the NRF connect SDK, which has a totally different handling of UUID values altogether.