Hardware
This page provides the necessary information to build a simple working prototype.
The following diagram gives an overview of the device components and their interactions.
The bzzzbz prototype (v1.0) uses a Raspberry Pi 3B+ as core of the system to exploit the capabilities of a Linux system with direct access to hardware. Custom electronics circuits are connected to the Pi's GPIOs in order to interface the Pi with the external analogue inputs: audio input and control surface. The following sections will outline each subsystem in detail.
The audio interface uses the WM8731 audio CODEC to perform analogue to digital conversion to the incoming audio signal (line input). The chip also provides headphones/line outputs that allow our prototype to have an audio output together with the generated visuals. Furthermore, the Linux kernel (v4.19) in the Raspbian OS comes with an integrated driver for the WM8731 so that the chip can be configured and used directly from the Raspberry Pi.
The chip is mounted on a breakout board in order to be connected to the Raspberry Pi header pins. The schematic for the breakout board is shown in the figure below:
The schematic and PCB files can be found in the hardware folder in the main repository under wm8731-breakout.
(say that a finished prototyped box and compact surface-mount pi-hat will be developed when the current restriction mesures are over).