Embedded demonstrator for audio manipulation

Abstract

Demonstration of embedded systems is a good way to motivate and recruit students to a future career in electronics. For Department of Electronics and Telecommunication at the Norwegian University of Science and Technology (NTNU), it is thus desirable to have an embedded demonstrator that gives the pupils an insight in what is actually possible when studying electronics at the university, a system that the department may present at different occasions. A good embedded demonstrator provides an interesting presentation of one or more topics related to electronics, and should be presented together with relevant theory in order to provide a level of education to the user.This report covers the implementation of an embedded demonstrator for audio manipulation on Altera's DE2 development and education board. The system is specified to demonstrate signal processing subjects like sampling and filtering through manipulation of analog audio signals. The main modules in the system are the Cyclone II 2C35 FPGA from Altera, running a Nios II soft-CPU, and a Wolfson WM8731 audio-codec. The specification of their operation is made with background in pedagogics theory in order to make the most interesting demonstration. To realize this specification, the system incorporates several design features for both activation and motivation of the user.The audio manipulator provides possibilities for comparison between different sample rates and filter characteristics in real-time operation. This makes the system well suited for practical demonstration of signal processing theory. Due to the presentation of perceivable results, in addition to the implementation of a user interface for interaction, the implemented audio demonstrator is considered to be a well suited platform for demonstration of topics related to electronics.