Breaking Changes in ArduinoJson 6.0

We have a quick update for you if you are handling JSON with any Arduino related project.

If you are using the library ArduinoJson to make your life easier, you may run into a problem with tutorials written prior to now (Including some of ours), where your code doesn't compile with errors related to the declaration of the jsonBuffer.

Don't worry, we have the solution for you.

ArduinoJson version 6.0 was recently released, and it included a breaking change which is most likely the cause to JSON related problems.

In the latest version, the concept of JsonBuffer has been replaced with the concept of JsonDocument.

Previously, you could create a JSON object like this:

StaticJsonBuffer<512> jsonBuffer;
JsonObject& root = jsonBuffer.createObject();

With the new changes, here's how you wpuld achieve the same thing:

StaticJsonDocument<512> jsonBuffer;
JsonObject& root = jsonBuffer.to<JsonObject>();

In the previous version of ArduinoJson, you would use the printTo() method to serialize json into a string, eg:

data.printTo(dataStr);

Now, you'll need to use the new serializeJson function:

serializeJson(data, dataStr);

For more information about other changes in ArduinoJson 6.0, check out this article.