Characteristics are the lowest and the most important echelon of the Bluetooth Low Energy technology. Encapsulated by a related service, these are the actual state variables, each of which stores a single piece of relevant measurement and information data:

Figure 14: Relationship of Characteristics, Service, and Profile

Just like services, these have a UUID, which can be 16-bit or 128-bit based, depending on whether a characteristic has a standard or custom definition. For example, the blood glucose measurement characteristic has a UUID of 0x2A35. Also, just like services, a manufacturer is free to define custom characteristics ...

Get IoT Projects with Bluetooth Low Energy now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.