Design and Implementation of a Flexible Temperature and Humidity Control System

Abstract

This paper proposes the design and implementation of a flexible temperature and humidity (T&H) control system using an Arduino board, a T&H sensor module and a mobile app via Bluetooth module. The T&H control system is flexible in operation. It can automatically control the T&H of the environment under the predetermined thresholds, and can also manually control the T&H by a smart phone through Bluetooth technology. The Arduino has a connection with a module that uses an LCD to show the humidity and ambient temperature. A dehumidifier and a cooling device regulate the humidity and temperature, correspondingly. When the temperature (alternatively, humidity) exceeds a predefined threshold, the cooling device (alternatively, dehumidifier) will automatically turn on. The temperature and humidity can also be controlled manually anytime by a smart phone, regardless of the predefined thresholds. A mobile app graphical user interface (GUI) is developed to display and control the current temperature and humidity. The T&H system has been successfully implemented on a prototype board with the developed software program. The hardware and software co-design as well as the mobile app development methods can be a good paradigm of engineering education in embedded systems.