ArduinoJson

Arduino JSON library

An elegant and efficient JSON library for embedded systems.

It's design to have the most intuitive API, the smallest footprint and works without any allocation on the heap (no malloc).

It has been written with Arduino in mind, but it isn't linked to Arduino libraries so you can use this library in any other C++ project.

Features

• JSON decoding
• JSON encoding (with optional indentation)
• Elegant API, very easy to use
• Fixed memory allocation (no malloc)
• Small footprint
• MIT License

Quick start

Decoding / Parsing

char json[] = "{\"sensor\":\"gps\",\"time\":1351824120,\"data\":[48.756080,2.302038]}";

StaticJsonBuffer<200> jsonBuffer;

JsonObject& root = jsonBuffer.parseObject(json);

const char* sensor = root["sensor"];
long time          = root["time"];
double latitude    = root["data"][0];
double longitude   = root["data"][1];

See complete guide

Encoding / Generating

StaticJsonBuffer<200> jsonBuffer;

JsonObject& root = jsonBuffer.createObject();
root["sensor"] = "gps";
root["time"] = 1351824120;

JsonArray& data = root.createNestedArray("data");
data.add(48.756080, 6);  // 6 is the number of decimals to print
data.add(2.302038, 6);   // if not specified, 2 digits are printed

root.printTo(Serial);
// This prints:
// {"sensor":"gps","time":1351824120,"data":[48.756080,2.302038]}

See complete guide

Testimonials

From Arduino's Forum user jflaplante:

I tried the [aJson and json-arduino] before trying your library. I always ran into memory problem after a while. I have no such problem so far with your library. It is working perfectly with my web services.

From Arduino's Forum user gbathree:

Thanks so much - this is an awesome library! If you want to see what we're doing with it - the project is located at www.photosynq.org.

From StackOverflow user thegreendroid:

It has a really elegant, simple API and it works like a charm on embedded and Windows/Linux platforms. We recently started using this on an embedded project and I can vouch for its quality.