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campbellsan edited this page Feb 5, 2015 · 33 revisions

Welcome to the Guzunty Pi Github Community

NEWS! Support for Raspberry Pi 2

Get yourself a kit here!

The purpose of the Guzunty Pi input/output expander is two-fold:-

  1. Protect the delicate GPIO pins of the Raspberry Pi computer and
  2. Provide up to a net 25 additional input/output expansion lines.

The objective is for it to do this at very low cost. To keep the cost down, it is designed for easy home assembly. Anyone should be able to build one of these for only about 15 bucks!

However, the Guzunty is much more than a simple I/O expander. It is programmable, so you can use it to do things that conventional line driver IC's could not achieve. Things which would otherwise use a lot of CPU time.

At the heart of the Guzunty is a Xilinx XC9500XL Complex Programmable Logic Device, or CPLD.

A CPLD is like several large breadboards laid out on your desk, full of every combination of logic devices you are ever going to need. It is waiting to be told what to do. It doesn't need a host of jumper wires like a breadboard would. It can be reprogrammed again and again (even at runtime), and it is small enough to fit on top of your Pi.

A CPLD program is often referred to as a ‘core’ to distinguish it from a regular computer program. Cores can do things thousands of times faster than an equivalent computer program.

This community has been started for Guzunty builders so that users can team up to create and share cores that work with the Raspberry Pi. We recommend you start with the FAQ's, then have a look at the cores available in the repository. You may well find a core already in there that does what you want (or maybe more than one).

Of course, even if you find what you are looking for, you can still learn to create your own cores if you want to. We guarantee you'll be glad you did, it will enable you to get even more out of this amazing, low cost device. Learn how to set up your computer to develop your own cores here.