HIGROTERM: An Open-Source and Low-Cost Temperature and Humidity Monitoring System for Laboratory Applications

Renan Rocha Ribeiro,Rodrigo Lameiras,Elton Bauer

doi:10.3390/inventions6040084

Abstract

Low-cost electronics developed on easy-to-use prototyping platforms, such as Arduino, are becoming increasingly popular in various fields of science. This article presents an open-source and low-cost eight-channel data-logging system for temperature and humidity monitoring based on DHT22 (AM2302) sensors, named HIGROTERM. The system was designed to solve real needs of the Laboratory of Material Testing of the Department of Civil and Environmental Engineering at the University of Brasília. The system design, functionalities, hardware components, source code, bill of materials, assemblage and enclosure are thoroughly described to enable complete reproduction by the interested reader. The terminologies and instructions presented were simplified as much as possible to make it accessible to the greatest extent to researchers from different areas, especially those without electronics background. The data-acquisition system has an estimated total cost of USD 96.00, or USD 136.00 if eight sensor nodes are included, with a considerable margin for cost reduction. The authors expect that the HIGROTERM system may both be a valuable low-cost and customizable tool for the readers, as well a source of innovation and interest in low-cost electronics for real problem-solving in various fields of science.

Highlights

The use of low-cost, open-source electronics prototyping, and do-it-yourself (DIY) platforms, has become increasingly common across all fields of science, in which needs for tailor-made solutions in budget-tight situations are recurrent
The Arduino platform [1] is among the most popular electronics prototyping platforms, with myriad applications reported in the literature, such as smartphone-integrated systems for environmental measurement [2], agricultural applications [3,4,5], landslide monitoring [6], meteorological applications [7], systems for indoor environmental monitoring and control with various types of sensors [8,9,10,11], Internet-of-Things (IoT) temperature and humidity systems [12], temperature and humidity measurements inside concrete structures [13], air quality monitoring [14], and custom-made printed circuit boards (PCBs) for various laboratorial automation [15]
At least eight simultaneous sensors’ channels were to be supported by the system, because it was deemed sufficient for the current needs at the Laboratory of Material Testing at the University of Brasília, but its design should enable the easy addition of more channels; 4

Summary

Introduction

The use of low-cost, open-source electronics prototyping, and do-it-yourself (DIY) platforms, has become increasingly common across all fields of science, in which needs for tailor-made solutions in budget-tight situations are recurrent. The need to monitor the temperature and humidity, two of the main environmental variables in building material studies, at many points in several environments simultaneously was common in many research projects conducted at the laboratory, being requirements of many standardized tests [17,18,19,20]. The environments varied in size and location: it could be the monitorization of several points across an entire room or many small experimental chambers or boxes located in a workbench. In this way, a multichannel sensor data logger system, capable of measuring temperature and humidity from small sensor nodes, with flexible deployment, seemed to be the appropriate solution to these problems

Methods

Results

Conclusion