This article presents the design of a complete radio system receiver to detect, in real time, the direction of arrival (DOA) of an incoming industrial, scientific, and medical (ISM)-band signal at 5.8 GHz. When a transmitter continuously sends a binary phase-shift keying (BPSK), modulated pseudo-noise (PN) code, the receiver estimates the DOA based on the received signal strength (RSS) and performs the channel sounding. The device that we describe includes a pattern-reconfigurable monopole antenna array, a front end, and a systemon-module (SOM). The SOM controls the antenna's main lobe direction by positive-intrinsic-negative (p-i-n) diode switching, configures the front-end modules, completes the data acquisition, and performs the digital signal processing (DSP) for the DOA estimation. The system has an average DOA resolution of 90° in the horizontal plane, with a success rate higher than 90%. It is presented as an educational platform for electrical engineering undergraduate and M.S. degree students.