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Deja OS

📒 Overview

Introduction

dejaOS is a JavaScript runtime environment designed for embedded devices, enabling low-cost, low-spec smart devices to run JavaScript code. It uses JavaScript as the development language, reducing costs and simplifying development. It make embedded application development easier. It has already shown excellent performance in various IoT scenarios.

Technical Background

dejaOS is built on the foundations of Mip/ARMLinux, QuickJS, and LVGL, enhancing development efficiency while maintaining high runtime performance.

• Mip/ARMLinux：Embedded Linux with system processes, threads, and resource scheduling capabilities.
• Quickjs：A compact and fast JavaScript engine that supports the ES2020 standard.
• LVGL：The most popular free open-source embedded graphics library, allowing easy creation of beautiful UIs using C, while dejaOS enables development with JavaScript.

Rich Features

dejaOS provides a comprehensive set of JavaScript Module, including:

• Hardware Interface Module: GPIO, PWM, UART, RS-485, RS-232, USB, Wiegand, Watchdog, Capturer, ALSA, NFC, QRCode, BLE, Face Recognition, etc.
• Networking and Communication Protocol Module: Net, TCP, TCP Server, MQTT, UDP, HTTP, Web Server, OSDP, etc.
• Graphics Module: Supports drawing GUI screens using JavaScript, compatible with all LVGL native capabilities.
• Utility Module: Threads, encryption/decryption, logging, EventBus, NTP, SQLite, etc.
• Third-Party Module: Supports using pure JavaScript third-party module with import (ESM).
• Native C Library Support: Allows development through embedded native C libraries wrapped in JavaScript.

🚀 Development Process

The development process for dejaOS app is as follows:

Prepare Development Environment

• Software Environment: Install Node.js (20+), VSCode, and DXIDE (VSCode plugin) on your computer.
• Hardware Environment: Currently, dejaOS is compatible with various smart devices primarily based on Ingenic and EeasyTech chips, with more being added continuously.

Prepare the Device

1. Purchase a development device.
2. Connect the development device to VSCode using a USB cableConnect the development device to VSCode using a USB cable.

Quick Start

• Write your first application in JavaScript code on VSCode, sync to the device in real time to see the effect, and view the run log on VSCode.

Build and Publish

1. Purchase production devices.
2. Build a DPK installation package in VSCode.
3. Use the DPK installation tool to install it on the production devices via serial connection.

🤖 Project structure

The main body of the project consists of five parts, as follows:

File	Required	Function
.temp	NO	Store temporary files
dxmodules	NO	Store dependent files
src	YES	Project logic
main.js	YES	Project entry file
app.dxproj	YES	Project configuration file

For a complete description of the project structure, please refer to Introduction to dejaOS Project Structure

▶️ Learning dejaOS

This list will guide you step by step to get started with dejaOS.

Document Introduction

• Introduction to dejaOS
• How to Install dejaOS
• Introduction to dejaOS-Compatible Devices
• Introduction to dejaOS's JavaScript Engine
• Introduction to dejaOS's GUI Engine
• Introduction to dejaOS Modules
• Introduction to DXIDE
• Introduction to dejaOS Project Structure
• dxLogger and Debugging Introduction
• App Packaging、Installation、Upgrade
• dejaOS System Mode Overview

Multithreading (Worker)

• Concept of Workers
• Asynchronous Operations
• Introduction to EventBus
• Introduction to dxMap and dxQueue
• Introduction to Thread Pools

GUI Introduction

• Basic Concepts of GUI
• Communication between GUI and Other Threads
• Introduction to dxUI Components
• Several Basic UI Examples

File Operations

• File System on the Device
• Reading and Writing Text Files
• Reading and Writing Binary Files

Hardware Interfaces

• Introduction to GPIO
• Introduction to PWM
• Introduction to UART
• Introduction to QR Code
• Introduction to NFC
• Introduction to Bluetooth
• Introduction to Audio

Network Interfaces and Protocols

• Introduction to Network Types
• Introduction to TCP Module
• Introduction to UDP Module
• Introduction to HTTP Module
• Introduction to MQTT Module

Database and Miscellaneous

• Introduction to SQLite and Basic Usage
• Introduction to Watchdog
• Introduction to Time Synchronization

Module Development Introduction

🤝 Services If you have any questions,contact us [email protected] and let us know how we can help.