Views:2337 Author:James Wu Publish Time: 2020-11-17 Origin:Site
In BLE applications, UUID (Universal Unique Identifier) is always used to identify Bluetooth services and communication access attributes. Different Bluetooth services and attributes use different access methods, just like people's language communication, only the same language can communicate normally.
The Bluetooth Special Interest Group (SIG) defines that: a UUID shares a basic UUID: 0x0000xxxx-0000-1000-8000-00805F9B34FB, totally 128 bits. To further simplify the basic UUID, each Bluetooth Special Interest Group defines a unique 16-bit UUID to replace the 'x' part of the basic UUID above. It uses 16-bit UUIDs for easy memory and operation, such as SIG which defines a 16-bit UUID of 0x180A for "Device Information" :
Different Bluetooth services have their own "Characteristic Code" defined for data access, allowing different attributes to be defined for read, write, notification, and for the corresponding channel, while the "Characteristic Code" also use UUID to uniquely identify, such as SIG's "Manufacture Name String" defined under the "Device Information" service implements the Read function with a 16-bit UUID of 0x2A29:
Obviously, the UUID of the Bluetooth service and the Characteristic Code play an important role in the interaction of the Bluetooth communication. The SIG standard allows users to customize the service, complete the Bluetooth service with 128 bits, and define the 128-bit Characteristic Code. In practice, Bluetooth modules from different manufacturers usually define their own Bluetooth services and signatures, which results in different manufacturers' Bluetooth modules on the market not communicating with each other.
In order to be better compatible with different manufacturer's Bluetooth service definitions, Bluetooth modules need to support service customization configuration function, which enables different manufacturer's Bluetooth modules to communicate with each other by supporting custom Bluetooth services and signature compatibility with different Bluetooth definitions. As a professional RF module supplier and one-stop IOT solution provider, DreamLnk offers various BLE modules, welcome to inquire!