A few years ago, I wrote a few columns titled Making A Thing. These columns were a tutorial of sorts for several different 3D modeling programs. This column wasn’t meant to be a complete guide to modeling an object in OpenSCAD or SolidWorks, it was just step-by-step instructions on how to make one specific thing with one specific piece of software.
More than a few people in the Hackaday community found this column useful or at the very least an interesting pedagogical device. When starting out with any kind of productivity software, you don’t need to know how to do everything, you just need to know how to do the most common tasks.
Since the Making A Thing column was so popular, I felt it was time to revive this idea with another design task we often face. As you have already guessed, we’re going to be making printed circuit boards. Continuing the unique tutorial format created in the previous iteration of this column, Making a PCB will build one specific circuit in multiple EDA suites.
The entire concept of demonstrating how to build one thing in a specific software package necessitates a model thing. Before I even begin writing the first Making A PCB column, I need to design something that’s sufficiently complex but still relatively simple, and something that’s hopefully somewhat useful. Breakout boards are extremely simple, perhaps too much. In the course of these programs, I’ll need to demonstrate how to make a part in each specific software suite, so fewer pins are better.
Lacking any creativity of my own, I’ve settled on a very small ATtiny85 Arduino derivative from Tim a.k.a. [cpldcpu]. Tim’s Nanite 85 is an exceptionally small Arduino-compatible board based on the ATtiny85, complete with a USB port, LED, and a few pins of I/O. It’s simple but sufficiently complex to give an introduction to a PCB design suite.
I’m not going to outright copy Tim’s Nanite 85, though. It’s much clearer if parts aren’t stacked on top of each other, and I’d like to give myself a little breathing room on the layout. I’ve redesigned the circuit of the Nanite 85 to use mostly through-hole parts on a slightly larger board. I’m calling my version the Nanite Wesley, and if you get that reference, thumbs up for you.
Is this how a board should be laid out? No, absolutely not. I could probably do this as a single-layer board. This is a very inefficient layout, and I like rounded corners on my boards. It’s good enough, though, and it works. This is meant to be a tutorial on how to use a PCB design package, not a tutorial on how to design a PCB. Your criticisms in this regard are noted and ignored.
What These Tutorials Will Consist Of
You cannot use a PCB design package until you know how to make a part. Yes, Eagle has wonderful libraries for almost everything you can imagine, KiCad has plenty of parts on the Internet, and if you’re using a cloud-based PCB software, almost everything will be provided for you. If you make a PCB, eventually you’ll have to make your own part, though, and each tutorial will begin with making a DIP-8 ATtiny85. Everything else on this board is a jellybean part. Either way, the process of making a part and package for a Zener is the same as making one for a microcontroller.
The next part of the tutorial will consist of schematic capture. This means placing the parts in the schematic, drawing wires between the pins and pads, and naming them. From there, it’s time to actually make a board, and this means dropping the parts down, putting traces between all the pins, doing the board outline, pouring copper, and mechanical considerations.
With the schematic and board designed, it will be time to send it off to a fab house. For Eagle and KiCad, this is easy; OSHpark accepts Eagle .brd and KiCad .pcb files, but this is cheating. We’re going to use CAM to generate real Gerber files. If you make enough PCBs, you’ll have to learn it eventually.
Caveats and Poor Design
There are a lot of things that go into making a ‘proper’ PCB, including isolation, direct traces to decoupling capacitors, making sure pixies don’t go around sharp corners and a thousand other items that won’t be discussed in these tutorials. There’s a reason I won’t be discussing this. This is a guide on how to use a PCB design tool, not how to design a PCB.
What else should I do?
As you can probably guess from the schematic above, the first PCB software I’m going to cover is Eagle. KiCad is on the list, as is Fritzing, Altium CircuitMaker, and OrCAD. In the interests of putting PCB design in a historical context, I have a copy of AutoTRAX and an old DOS machine. I’ll also be covering a few of the cloud-only design tools such as Upverter.
That’s enough software suites to get started, but as with the Making A Thing series, I’m going to be looking for suggestions from the peanut gallery. I can’t change the circuit I’m making, as that’s the entire point of this series, but I am looking for suggestions on other tools to cover. What else can I do? Want me to grab a piece of copper clad board, sticker overlays, and some photostatic film? I can do that. Are you at a web-based EDA startup, and want some free advertising? Leave a note in the comments.
Thanks to our efforts to slowly improve the backend of Hackaday, you’ll be able to access all the Making A PCB In Everything posts from the series list below.