Hi Christopher, The term "unique" will vary based on context. In the context of a Gatt Service and Characteristic, it is intended to uniquely identify the "contract" defined by the service/characteristics. For example a Temperature Service would have a UUID that universally defines the contract/interface defined by that service. So for your custom service, you'll need to define a set of 20 128 bit UUID (16 bit uuids are reserved for SIG defined uuids) that uniquely identify the contract that's defined by your service/characteristics. The devices can uniquely be identified/addressed by their respective addresses. I hope this is helpful. Thanks! Alain On Tue, May 26, 2020 at 10:38 AM Christopher de Vidal <cbdevidal.jk1@xxxxxxxxx> wrote: > > Help a newbie? I'm seeking to build a niche product for sale, a > Raspberry Pi-based device which during the initial setup acts a BLE > peripheral. (Python using dbus to Bluez.) It has a single service and > 19 characteristics. I get that the first "U" in UUID stands for > unique. Must that be unique among each physical product, or may it be > unique among the product line? > > So if I sell 1,000 units (which would be a success), would I need to > obtain 1,000 service UUIDs and 19,000 characteristic UUIDs? Or just 20 > total, for the entire product line? > > The goal is so that the iOS/Android app can have that pre-set in the > code and quickly discover the device, pair it automagically. > > I suppose the risk is of a conflict of two similar devices which are > in the same vicinity of the phone, and both set into peripheral mode > at the same time. But that would be a minimal risk which I could > accommodate for. > > Christopher de Vidal > > Would you consider yourself a good person? Have you ever taken the > 'Good Person' test? It's a fascinating five minute quiz. Google it.
