Telink TLSR8232 BLE SDK Developer Handbook
AN-19112700-E1
91
Ver.1.0.0
Figure 3-29 GATT Service Containing Attribute Group
The basic contents and properties of an Attribute are shown as below:
1) Attribute Type: UUID
The UUID is used to identify Attribute type, and its total length is 16 bytes. In BLE
standard protocol, the UUID length is defined as two bytes, since Master devices
follow the same method to transform 2-byte UUID into 16 bytes.
When standard 2-byte UUID is directly used, Master should know device types
indicated by various UUIDs. 5316 BLE stack defines some standard UUIDs in
“stack/ble/service/hids.h” and “stack/ble/uuid.h”.
Telink proprietary profiles (OTA, etc.) are not supported in standard Bluetooth. The
16-
byte proprietary device UUIDs are defined in “stack/ble/uuid.h”.
2) Attribute Handle
Slave supports multiple Attributes which compose an Attribute Table. In Attribute
Table, each Attribute is identified by an Attribute Handle value. After connection is
established, Master will analyze and obtain the Attribute Table of Slave via “Service
Discovery
” process, then it can identify Attribute data via the Attribute Handle during
data transfer.
3) Attribute Value
Attribute Value corresponding to each Attribute is used as data of request, response,
notification indication and confirm. In 5316 BLE stack, Attribute Value is indicated by
one pointer and the length of the area pointed by the pointer.