Electronic Design¶
A designer won’t use Mecrisp-Stellaris in isolation, he may initially use a cheap and easily available device such as a ST Discovery Board to try out the MCU and coding ideas but these boards are just educational, they’re not suited for an actual device in the field, be it a industrial process controller or a weather station.
Main Components¶
I make extensive use of Open Source programs and use the gEDA family of design components for all my work. http://wiki.geda-project.org/geda:gaf.
All things have a beginning and an end, and our beggining is the Circuit Diagram. Everything starts here.
gSchem¶
Schematic Capture¶
Schematic Capture is the part that draws the circuit diagram.
Schematic Capture has a rich history, and it’s worth knowing how we came to be where we are today, and why.
Like everything else, Schematic Capture started with a pen and paper, straight from the designers mind to paper and from there to the circuit board. In time, computers and computer programs became available to do most of the work, they had libraries of components that knew the available package types and the functions of the pins, be they inputs, outputs or analog.
Initially these programs ran on massive mainframes, and small mainframes all under Unix and they were massively expensive.
Eventually they ran on the ubiquitous IBM PC. One fine example is ORCAD for DOS ($180 AUD) which I owned in the late 1970’s. Later examples ran on Microsoft Windows such as “Protel” (Now Altium) which cost $5000 AUD and was very slow at the time.
The Golden Age of Computing came with the General Purpose License and the age of Free Schematic Capture had arrived!
Note
There are many fine Open Source programs such as Kicad, but as I only use gEDA, that’s all I’m qualified to discuss here.
gSchem¶
To me, the first decent Open Source Schematic Capture was the GPL’d gSchem by Ales Hvezda and written using a LISP variant “Guile” in 1998. gSchem reminds me of Orcad for DOS every time I use it on Unix and I have used gSchem now for almost a quarter of a century !
gSchem is used for¶
Schematic capture
Creating library parts
Generating netlists
Creating library parts¶
gEDA has a massive library, see http://www.gedasymbols.org/ which is maintained by DJ Delorie.
Generating netlists¶
This is a massive area as netlists are a intermediate form which is input into other programs to complete a design.
