#ifndef DATAHANDLER_HPP #define DATAHANDLER_HPP #include class DataHandler { public: // Singleton static DataHandler& GetInstance() { static DataHandler instance; return instance; } // Public functions String getJsonData(); void updateTemperatureData(float temperature); void updateHumidityData(float humidity); private: // Singleton DataHandler(); ~DataHandler(); DataHandler(const DataHandler&) = delete; DataHandler& operator=(const DataHandler&) = delete; float temperature; float humidity; String buildJson(); }; #endif