Software Architecture

The software architecture of the GR551x SDK is shown in Figure 3.

• Bootloader

  It is a boot program used for GR551x software and hardware environment initialization, and to check and start applications.

• BLE Stack

  It is the implementation core of BLE protocol stacks. It consists of Controller, HCI, and Host protocols (including ATT, L2CAP, GAP, SM, and GATT), and supports roles of Broadcaster, Observer, Peripheral, and Central.

• Bluetooth LE SDK

  It refers to software development kit that provides easy-to-use SDK Bluetooth LE APIs and SDK System APIs.

  • SDK Bluetooth LE APIs: include L2CAP, GAP, SM, and GATT APIs.
  • SDK System APIs: provide API definitions for Non-volatile Data Storage (NVDS), Device Firmware Update (DFU), system power management, and generic system-level access interfaces.
• Application

  The SDK provides abundant Bluetooth and peripheral example projects. Each project contains compiled binary files; users can download these files to GR551x SoCs for operation and test. Android applications in the SDK also provide corresponding functions as most Bluetooth applications do, to help users with tests.

• Drivers

  API definitions and descriptions on peripheral drivers. For more information about drivers, see GR551x HAL and LL Drivers User Manual.