Design and Implementation of a RF gateway for Monitoring Devices

Abstract

Several technologies employing sometimes opposite working principles are used for the Internet of Things scope. The first part of this work is dedicated to the study of the main technologies in order to choose which can be used now to send monitoring data coming from devices of a company. To implement a proof of concept of data sending with these technologies to the cloud, commercially existing boards are used and a software is created and loaded in a microcontroller. The role of this microcontroller is to collect the data with wired communication on the devices side and send it to the cloud with wireless communication by controlling a radio frequency daughterboard on the other side. As a company does not want to waste money by buying expensive boards that present useless functionality, custom boards which include only what is necessary for the company are designed and their size minimized. The main board and its wireless technology daughterboards form a modular radio frequency gateway whose technology can be easily changed. Radio frequency technologies are sensitive to attenuation through buildings, walls and objects as well as the location and orientation of their antennas. This is why tests are conducted to compare the power received in function of the antenna location and orientation as well as the presence or absence of physical barriers. These tests lead to the conclusion that the antenna must be placed outside or near windows without perturbing elements near it and vertically to maximize the quality of transmission.