Introduction

This document specifies the API for developing BLE Applications and other Applications.

GR551x provides three classes of APIs for developer:

- The BLE API to develop various BLE Applications using the BLE interfaces.

​ Please refer to Definitions and Prototypes for BLE SDK

- The Peripheral API to access the various peripherals of MCU.

​ Please refer to Definitions and Prototypes for Peripheral

- The System API to acquire and utilize system resources, such as software timer.

​ Please refer to Definitions and Prototypes for System API

> Note: The latest API version number for SDK Developer Guide is 1.6.10.