Volume 16, Number 2
Low-Cost Digital Data Transmission Technique using FM-RDS Protocol for the Agricultural Sector in Developing Countries
Authors
Ndangoh Dam Arantes and Michael Ekonde Sone, University of Buea, Cameroon
Abstract
Existing monitoring systems in developing countries are deficient in detecting diseases and other factors that adversely affect agricultural productivity. This paper presents a low-cost method of disseminating information to farmers by transmitting digital data over an FM channel. The low-cost method is employed in a poultry pen where temperature variations are broadcasted using the radio-text field of the FM-RDS protocol. The system uses a FLIR Lepton 3.5 sensor embedded in a tCam-Mini Rev4 thermal camera to capture temperature values. The FM-RDS transmitter program reads the temperature file every 60 seconds and displays the temperature in the radio-text field of the RDS protocol on an FM station. Differential BPSK is applied to the output of the subband encoder to place the text file on the 57 kHz subcarrier on the FM spectrum. The SDR Touch app decodes the FM-RDS signal using a combination of hardware and software processing. Experimental results show that using the RDS protocol, temperature values could be reliably transmitted with 100% signal quality in a noise-free environment as shown on the advanced RDS features of the SDR Touch app. A signal quality of 95% or more is deemed adequate.
Keywords
Sub band coding, Software-defined radio, FM-RDS, Pi FM transmitter, Thermal imaging.