ArduinoJson

ArduinoJson
Name	ArduinoJson
Developer	Benoît Blanchon
Initial release	2014
Latest release	6.x
Repository	GitHub
Programming language	C++
License	MIT

ArduinoJson

ArduinoJson is a C++ library for parsing, generating, and manipulating JSON on embedded systems and microcontrollers. It targets constrained hardware such as boards from Arduino, ESP8266, and ESP32, and is used in projects involving Raspberry Pi, BeagleBone Black, STM32, and Particle devices. The library integrates with ecosystems including PlatformIO, Arduino IDE, Visual Studio Code, and Eclipse for embedded development.

Overview

ArduinoJson was created to provide a compact, efficient JSON solution for resource-limited devices produced by organizations such as Arduino SA, Espressif Systems, STMicroelectronics, and NXP Semiconductors. It competes with parsing libraries used in larger projects like RapidJSON, nlohmann/json, Boost.JSON, and jansson while remaining suitable for single-board microcontrollers found in projects promoted by Maker Faire, Adafruit Industries, and SparkFun Electronics. The library has been cited in tutorials and books from publishers like O'Reilly Media, No Starch Press, and Packt Publishing and appears in community forums hosted by Stack Overflow, Hackster.io, and GitHub discussions.

Features and Architecture

ArduinoJson's architecture emphasizes zero-allocation parsing alternatives and manual memory management strategies akin to approaches in Embedded Systems Programming and projects from ARM Holdings and Atmel (Microchip Technology). It offers a DOM-like API and stream-based processing similar to models used by SAX parsers in projects influenced by Apache Software Foundation libraries. Core features include serialization compatible with implementations from Mozilla and Google projects, support for unicode handling used in ICU-based systems, and integrations enabling communication with cloud services such as AWS IoT, Microsoft Azure, and Google Cloud Platform.

API and Usage

The API exposes types and methods that mirror patterns in C++ libraries by maintainers at Herb Sutter-influenced communities, and follows idioms familiar to developers who use STL-like containers from libstdc++ and LLVM libc++. Typical usage covers parsing JSON payloads received via transports from MQTT brokers like Mosquitto or HTTP interactions using stacks from lwIP and Mbed TLS. The library is often employed in projects integrating with services such as IFTTT, Home Assistant, Node-RED, and InfluxDB where small-message serialization is critical. Examples in documentation reference interoperability patterns found in ArduinoJson's author projects and community codebases on GitHub and GitLab.

Performance and Memory Considerations

ArduinoJson emphasizes predictable memory usage through a StaticJsonDocument and DynamicJsonDocument model, paralleling memory strategies seen in FreeRTOS and Zephyr Project applications. Benchmarks compare favorably when juxtaposed with parsers like RapidJSON and cJSON on devices based on processors from ARM Cortex-M families, ESP32-S2 variants, and RISC-V microcontrollers supported by vendors like SiFive. Memory-constrained designs often pair the library with optimization tools from GCC and Clang toolchains and profiling utilities such as Valgrind (where applicable) and vendor-specific debuggers like OpenOCD and Segger J-Link.

Supported Platforms and Compatibility

ArduinoJson supports a wide range of platforms including boards from Arduino, Adafruit Industries Feather series, Raspberry Pi Pico, ESP8266, ESP32, and microcontroller families from STMicroelectronics and Texas Instruments. It compiles with toolchains maintained by projects like GCC, Clang, and ARM Compiler and integrates into build systems including CMake, Make (software), PlatformIO, and Arduino CLI. Community ports and examples extend to environments such as MicroPython and CircuitPython workflows where C/C++ bindings are relevant.

Development, Maintenance, and Licensing

ArduinoJson is primarily developed by Benoît Blanchon and maintained via a public repository on GitHub, with contributions and issue reports coming from users across communities like Stack Overflow, Reddit, and Hackster.io. The project follows contribution practices inspired by governance models from Linux Foundation projects and uses continuous integration services comparable to Travis CI, GitHub Actions, and CircleCI. It is distributed under the MIT License, aligning with permissive licensing used by libraries such as zlib and SDL, facilitating inclusion in both open-source and commercial products developed by companies like Bosch, Siemens, and Schneider Electric.

Category:Embedded systems