So let me make sure I understand. The devices themselves have their own Bluetooth addresses (similar to MAC addresses, I don't know the proper term) which are unique among every physical device sold. And also there is one (and only one) service UUID which is shared among all 1,000+ peripherals which I sell, and 19 characteristic UUIDs that are shared among the physical peripherals. The devices come with their own Bluetooth "MAC" and I only need to obtain 20 UUIDs in total for the product line. Did I get that right? 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. On Tue, May 26, 2020 at 10:57 AM Alain Michaud <alainmichaud@xxxxxxxxxx> wrote: > > 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.