Design and Implementation of a LoRa-Based Drone Audio Message Broadcasting System

This paper presents the design and implementation of a drone-based audio message broadcasting system using LoRa (Long Range) wireless communication technology. The system addresses a communication gap observed in several localities in Benin, where public announcements are still delivered by traditional town criers prone to human error. The proposed system consists of two electronic blocks: a ground-based transmitter unit and an airborne receiver unit mounted on a DJI Mini 2 drone. The transmitter block, built around an ESP32 microcontroller and a LoRa SX1278 Ra-02 module, receives broadcast commands from a web-based frontend via a Node.js server. The receiver block, also based on an ESP32 and LoRa module, retrieves pre-recorded audio files from a micro SD card and plays them through MAX98357A digital audio amplifiers connected to 8Ω loudspeakers. Circuit design was performed using KiCad EDA and the system was validated through functional testing. Results confirm the feasibility of deploying UAV-based audio broadcasting systems for community communication in sub-Saharan Africa.