Teaching Digital Signal Processing Course with a Real Time Digital Crossover System for Electrical and Computer Engineering Technology Students

This paper presents pedagogies and experiences for teaching digital signal processing (DSP) with real-time processing experiences in the electrical and computer engineering technology (ECET) program using a digital crossover system. In our ECET curriculum, the engineering technology students often face their challenging in studying the signal processing related courses due to the use of heavy mathematics. Although adopting MATLAB as an analysis and simulation tool is a great help, the engineering technology students are especially motivated by their real-time processing learning experiences. To accommodate such a learning environment, our DSP course with laboratories has been improved, in which each lab concurrently requires MATLAB simulations as well as real-time processing coding with a digital signal processor such as Texas Instruments' TMS320C6713 DSK. This DSP course is the second signal processing course in electrical and computer engineering technology (ECET) program. The pre-requisite includes student working knowledge and skills of Laplace transform, Fourier series, Fourier transform, and different types of analog active filter design. After completing the course, students not only become familiar with MATLAB software development tools, but also gain the real-time analog signal processing experience. In this class, they learn to design digital low-pass, high-pass and band-pass filters and then program them using MATLAB and C, and apply the software and hardware interface for real speech applications such as in a crossover system. Comparing with the traditional DSP course which mainly focus on heavy mathematical development in sampling and recovering, spectrum analysis, FIR or IIR filter design with the limited computer simulations, our real-time crossover project allows students easily understand how a speech signal or music being processed and separated by a bass (woofer) and a tweeter after they design the proper low-pass and high-pass filters and apply two DSP boards (TI TMS320C6713 DSK). Therefore, in this paper, we first present a complete digital crossover platform, MATLAB design and simulations, developed C code inserted in both of DSP boards, crossover outputs and test results. Secondly, we address the outcomes of students learning achievement including continuous applications of their acquired DSP skills in other related courses and their motivations for continuing to pursue the upper-level signal processing related courses such as the advanced digital signal processing with multimedia applications. More importantly, we examine the course assessment according to analysis of the collected data from students' learning outcome survey, project evaluation, and further address the possible improvements of the course content based on our assessment.