Our project consisted of several high level areas, seen on the block diagram below. The main component of the project is the effects processor segment. This segment takes an analog signal as input, processes it according to the user's specification, and then puts the modified audio signal as output to a speaker or amplifier.

In order to achive these modifications inside of a computer processor, we need to perform some Analog-to-Digital conversion. Ideally, this conversion would occur somewhere near the standard rate of 44.1 MHz, which is more than double what the human human ear can pick up. This is in accordance with the Nyquist rate, which says that you should sample at least two times faster than the highest frequency that you hope to obtain in sampling an analog signal. Once the data is quanitized and represented digitally, the effects algorithms will dictate how it is modified. Reference 1 is a link to a paper by Professors of Software Engineering in a Romanian University that describes the implementation of audio effects using DSP. Their block diagrams and code snippets guided our algorithm design. However, the effects processing basically boils down to an infinite loop where the data is grabbed, handed to the selected effects' algorithm, and then the modified signal is returned. Lastly, the signal is converted back to analog using an Analog-to-Digial converter and the modified signal is heard through a speaker.

The next component is the user interface section. The selection options are shown to the user through an Liquid Crystal Display (LCD), and the user is given a Nintendo 8 controller to navigate the menu and select the desired effect.

High Level Component Diagram

High Level Design

Hardware Design