Open Hardware Open Source

This is a slight digression from the technical details of the camera itself, and into matters of infrastructure. Specifically, I'd like to spell out my choices for development and sharing tools. A goal of this project is to share the source code (i.e. design files) openly; but rather then complete the project and release only the final result, I intend to make the design files available as I work on them. That obviously means that the tools I use to manipulate the source files need to be tools available to potential users. The easiest way to manage that is to user open source tools wherever possible. And for electronics design and embedded programming, open source tools get me pretty far.

Schematics and PCB Layouts

This suite of tools is going to be the first to be put to use, as I'm going to be drawing at least partial schematics before anything else. There are a few open source schematic editors available: KiCAD, Electric and GEDA/gschem are common examples. Personally, I choose GEDA/gschem because that's what I'm most comfortable with. I also know that the integration with PCB, the circuit board layout editor, is thorough and advanced. So I see no reason to change my habits.

Logic Design

The camera system as a whole will have at least 2 FPGA devices: one in the camera module and one in the processor module. The design that goes into these devices will be described in Verilog, with the designs simulated by Icarus Verilog and synthesized by the vendor tools for the chosen device. Since the chosen devices are likely to be Xilinx parts, the vendor synthesizer is likely to be WebPACK. (Altera does not support Linux with its web edition software. Big strike against Altera.)

Embedded Systems/Software

As I mentioned back in an earlier blog entry, the processor module will likely be built around a Gumstix single board computer. That right there implies the embedded runtime operation system is Linux. The tools and techniques for programming embedded Linux are well known and mature. There is no need right now to pin it down any further then that.

Source Code Control/Distribution

The source code control system will need to carry schematics, printed circuit board layouts, Verilog design files, and C/C++ source code for the processor module, as well as assorted text files for various other purposes. The source code control should also act as a repository, that helps make all these files available to interested users. There is a convenient hosting service at GitHub that I've used in the past for other purposes. This service (and others like it) offer storage and services for public "git" repositories. GitHub in particular has far better performance then sourceforce.net, and has been reliable for other projects that I've hosted there.

The git URL for the astrocam project is "git://github.com/steveicarus/astrocam.git". The quick way to get the current sources, then, is:

git clone git://github.com/steveicarus/astrocam.git

For now, that is where the source lives. There is very little there now, but that is where it will go. Text files within the distribution directory will describe the finer details of how to view/compile the source files.