Low-Cost Software Defined Radio Transmitter using Raspberry Pi and HackRF One

Abstract

Software Defined Radio (SDR) enables flexible and reconfigurable wireless communication by replacing most hardware-based signal processing with software, reducing cost and complexity. This paper aims to design and implement a low-cost SDR transmitter for short-range FM audio broadcasting using a Raspberry Pi 4 and HackRF One module. The system operates within the 1 MHz to 500 MHz range and utilizes GNU Radio for real-time modulation, filtering, and transmission control, adopting a homodyne architecture for simplicity, compactness, and energy efficiency. Hardware components, software configuration, and signal processing flowgraphs were developed and integrated into a functional prototype. Experimental results demonstrated stable FM transmission over distances up to 50 meters, delivering clear audio at short range and acceptable quality at maximum distance. These findings highlight the system’s potential as an affordable platform for education, experimentation, and rapid prototyping in wireless communications.