The laboratory has been used in several ways since the fall of 1994. More than 200 students from all engineering disciplines and the liberal arts have been introduced to basic concepts of signal analysis and digital signal processing in the ``Exploring Engineering'' course [6]. The laboratory is also used for classroom demonstrations in several courses to illustrate sampling, aliasing, digital filtering, and modulation.
Electrical engineering students in the junior year at Bucknell University have used the laboratory to develop design projects in the ``Signals and Systems'' course during 1994 and 1995. The project spans the final four to five weeks of the semester. Students are expected to choose a topic for the project, design an appropriate system model or algorithm, simulate the design, and implement the system in real-time to process actual signals or control a real system.
During 1994, the real-time implementations were programmed in C language, since the graphical programming interface was not yet available. Most projects in that year were limited to one or more digital filters with some simple logic. The digital filters were designed with Matlab and manually implemented in C. Example projects included a digital crossover network for audio speakers, digital bandpass filters to isolate harmonics in a signal, a detector for a subset of telephone touch-tones (DTMF), digital demodulation of AM signals, and a digital guitar tuner.
During 1995, the availability of the graphical programming interface produced a considerable improvement in the level of the projects. The freedom from C programming allowed students to focus more attention on system design and signal processing issues. The following subsections describe selected design projects from the 1995 course.