Introduction

What is Nexus?

Nexus is a world-class embedded software development platform designed for building reliable, secure, and portable embedded applications. It provides a comprehensive set of abstraction layers and middleware components that enable developers to write code once and deploy across multiple MCU families.

Key Features

• Unified APIs: Consistent interfaces across different hardware platforms

• Portability: Write once, run on multiple MCU families (STM32, ESP32, nRF52)

• Quality: MISRA C compliant, thoroughly tested code with 90%+ coverage

• Security: Built-in security features for IoT applications

• Real-time: Support for FreeRTOS and bare-metal configurations

• Ecosystem: Rich middleware, cloud integration, and tooling

Why Nexus?

For Embedded Developers:

• Reduce time-to-market with ready-to-use components

• Focus on application logic instead of low-level drivers

• Easy migration between MCU platforms

For Teams:

• Consistent coding standards across projects

• Comprehensive documentation and examples

• Active community and support

Architecture Overview

Nexus follows a layered architecture that separates hardware-specific code from application logic:

┌─────────────────────────────────────────────────────────────┐
│                      Applications                            │
├─────────────────────────────────────────────────────────────┤
│                      Middleware                              │
│  ┌─────────┐ ┌─────────┐ ┌─────────┐ ┌─────────┐           │
│  │  Shell  │ │   Log   │ │  Config │ │  Event  │           │
│  └─────────┘ └─────────┘ └─────────┘ └─────────┘           │
├─────────────────────────────────────────────────────────────┤
│                         OSAL                                 │
│  ┌─────────┐ ┌─────────┐ ┌─────────┐ ┌─────────┐           │
│  │  Task   │ │  Mutex  │ │  Queue  │ │  Timer  │           │
│  └─────────┘ └─────────┘ └─────────┘ └─────────┘           │
├─────────────────────────────────────────────────────────────┤
│                          HAL                                 │
│  ┌─────────┐ ┌─────────┐ ┌─────────┐ ┌─────────┐           │
│  │  GPIO   │ │  UART   │ │   SPI   │ │   I2C   │           │
│  └─────────┘ └─────────┘ └─────────┘ └─────────┘           │
├─────────────────────────────────────────────────────────────┤
│                    Platform / Hardware                       │
│  ┌─────────┐ ┌─────────┐ ┌─────────┐ ┌─────────┐           │
│  │ STM32F4 │ │ STM32H7 │ │  ESP32  │ │  nRF52  │           │
│  └─────────┘ └─────────┘ └─────────┘ └─────────┘           │
└─────────────────────────────────────────────────────────────┘

Layer Descriptions

Application Layer

User applications built on top of Nexus platform.

Middleware Layer

Common services including logging, shell, configuration management, and event handling.

OSAL (OS Abstraction Layer)

Portable interface for RTOS primitives: tasks, mutexes, semaphores, queues, and timers. Supports FreeRTOS and bare-metal backends.

HAL (Hardware Abstraction Layer)

Unified API for hardware peripherals: GPIO, UART, SPI, I2C, Timer, ADC. Hides hardware differences from application code.

Platform Layer

MCU-specific implementations including startup code, linker scripts, and vendor SDK integration.

Supported Platforms

Platform	MCU	Status	RTOS Support
STM32F4	STM32F407VGT6	✅	FreeRTOS, Bare
STM32H7	STM32H743ZIT6	🚧	FreeRTOS, Bare
ESP32	ESP32-WROOM-32	🚧	FreeRTOS
nRF52	nRF52840	🚧	FreeRTOS, Zephyr
Native	x86/x64	✅	pthreads

Legend: ✅ Supported, 🚧 In Progress

Project Structure

nexus/
├── hal/                    # Hardware Abstraction Layer
│   ├── include/            # Public headers
│   └── src/                # Common HAL code
├── osal/                   # OS Abstraction Layer
│   ├── include/            # Public headers
│   └── adapters/           # RTOS adapters (FreeRTOS, native)
├── framework/              # Middleware components
│   └── log/                # Logging framework
├── platforms/              # Platform-specific code
│   ├── stm32f4/            # STM32F4 platform
│   └── native/             # Native (PC) platform
├── applications/           # Example applications
├── tests/                  # Unit tests
├── docs/                   # Documentation
└── cmake/                  # CMake modules and toolchains

License

Nexus is released under the MIT License. See the LICENSE file for details.

Getting Started

Ready to start? Follow these guides:

1. Installation - Set up your development environment

2. Quick Start - Build your first Nexus application

3. Architecture - Deep dive into the architecture