The Generic Attribute Profile (GATT) defines a service framework using the Attribute Protocol. This framework defines procedures and formats of services and their characteristics. The procedures defined include discovering, reading, writing, notifying, and indicating characteristics, as well as configuring the broadcast of characteristics. In GATT, the Server and Client are two different kinds of GATT roles, it's useful to separate.

What is GATT Server?

A service is a collection of data and associated behaviors to accomplish a particular function or feature. In GATT, a service is defined by its service definition. A service definition may contain referenced services, mandatory characteristics and optional characteristics. A GATT Server is a device that stores attribute data locally and provides data access methods to a remote GATT Client paired via BLE.

What is GATT Client?

A GATT Client is a device that accesses data on a remote GATT Server, paired via BLE, using read, write, notify, or indicate operations. Once two devices are paired, each device can act as both a GATT Server and a GATT Client.

Currently, Feasycom Bluetooth Low Energy modules could support GATT Server and Client. In regards to different customers' requirements, Feasycom designed a variety of BLE modules, e.g. the small size Nordic nRF52832 module FSC-BT630, TI CC2640 module FSC-BT616. For more information, welcome to visit the link: