BT GATT Client provides the interfaces to use Bluetooth GATT client feature.
Before calling any GATT client function, the Generic Access Profile needs to be initialized (see bt_hal_manager.h and bt_hal_manager_adapter.h). After GAP has been initialized, the functions need to be called in the following order:
The BT-GATT client interface is represented by BTGattClientInterface_t
The BT-GATT client callbacks can be found here BT-GATT Client Callbacks