Chapter 2 Introduction

Figure 2.1: SDK Overview

INGCHIPS software development kit has following major components (see Figure 2.1):

1. Core Tools

   Provide project wizard, flash loader and other functionalities. These tools make BLE development easy and seamless.

2. Language & IDE Integration

   Support Keil μVision¹, IAR Embedded Workbench², Rowley Crossworks for ARM³, and SEGGER Embedded Studio for ARM⁴. All IDE/Toolchain settings are configured by core tools properly and automatically. GNU Arm Embedded Toolchain⁵ is also supported.

3. Platform Bundles

   Provide different bundles for different application scenarios (such as typical, and extension). Each bundle contains full stack & (optional) FreeRTOS binary, and C header files. Source codes for accessing peripherals are also provided.

4. Examples

   Provide a rich set of BLE device examples and corresponding Android and iOS referencing applications.

5. Documentation

   User guide (this document), API reference, and application notes are also provided.

2.1 Scope

This document covers platform overall architecture, core tools and platform APIs.

2.2 Architecture

There are two variants of bundles, one with built-in FreeRTOS (RTOS Bundles), and one without built-in RTOS (“NoOS” Bundles).

2.2.1 RTOS Bundles

ING918xx/ING9186xx software architecture is shown in Figure 2.2. Bootloader is stored in ROM and can’t be modified, while platform and app executable are stored in flash. Platform executable is provided for each bundle. BLE stack, FreeRTOS and some SoC functionality are compiled into this single platform executable. When system starts up, platform executable initializes, then loads the primary app executable.

Figure 2.2: Architecture

A secondary app can only be asked to execute programmaticly. It is possible to download several secondary apps, and to switch between them programmaticly. After reset, platform will load the primary app executable as usual. Entry address of the primary app is managed by SDK tools, while entry addresses of secondary apps can be configured manually.

2.2.1.1 Apps built with C

App executable’s main function is named app_main, where app gets initialized:

int app_main(void)
{
    ...
    return 0;
}

app_main should always return 0.

Platform, BLE stack and FreeRTOS APIs are all declared in corresponding C header files. To use these APIs, just include the necessary header files.

2.2.1.2 Other Languages

Languages can also be used to build apps, for example:

• Rust⁶

• Nim⁷

• Zig⁸

2.2.2 “NoOS” Bundles

When developers want to use other RTOS, or use features that are missing in those RTOS bundles, developers can choose the “NoOS” bundles.

A generic RTOS interface is defined, and developers should provide an implementation of this interface to platform binaries through the returning value of app_main:

uintptr_t app_main(void)
{
    ...
    return (uintptr_t)os_impl_get_driver();
}

2.3 Abbreviations & Terminology

Table 2.1: Abbreviations

Abbreviation	Notes
ATT	Attribute Protocol
BLE	Bluetooth Low Energy
FOTA	Firmware Over-The-Air
IRQ	Interrupt Request
GAP	Generic Access Profile
GATT	Generic Attribute Profile
RAM	Random Access Memory
ROM	Read Only Memory
SDK	Software Development Kit

Table 2.2: Terminology

Terminology	Notes
Flash Memory	An electronic non-volatile computer storage medium
FreeRTOS	A real-time operating system kernel

2.4 References

1. Host API Reference

2. Bluetooth SIG⁹

3. FreeRTOS¹⁰

4. Mastering the FreeRTOS™ Real Time Kernel¹¹

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1. https://www.keil.com/↩︎

2. https://www.iar.com/iar-embedded-workbench/↩︎

3. https://www.crossworks.com/index.htm/↩︎

4. https://www.segger.com/products/development-tools/embedded-studio/↩︎

5. https://developer.arm.com/open-source/gnu-toolchain/gnu-rm↩︎

6. https://ingchips.github.io/blog/2022-09-24-use-rust/↩︎

7. SDK example: Smart Home Hub.↩︎

8. SDK example: Central FOTA.↩︎

9. https://www.bluetooth.com/↩︎

10. https://freertos.org↩︎

11. https://www.freertos.org/Documentation/161204_Mastering_the_FreeRTOS_Real_Time_Kernel-A_Hands-On_Tutorial_Guide.pdf↩︎