Setup a json message buffer with ArduinoJson

arduino_json.cpp

#include <Arduino.h>
#include <ArduinoJson.h>

void setup()
{
  Serial.begin(115200);
}

void loop(){
  const size_t bufferSize = JSON_OBJECT_SIZE(5);
  DynamicJsonBuffer jsonBuffer(bufferSize);

  JsonObject &root = jsonBuffer.createObject();
  root["temp"] = 23;
  root["humid"] = 44;
  root["temp_f"] = 78;
  root["loc"] = "bedroom;
  root["key"] = "key";

  char JSONmessageBuffer[300];
  root.prettyPrintTo(JSONmessageBuffer, sizeof(JSONmessageBuffer));
  Serial.println(JSONmessageBuffer);
}