Schematic-o-matic

Tricked-Out Breadboard Automatically Draws Schematics Of Whatever You Build

When it comes to electronic design, breadboarding a circuit is the fun part — the creative juices flow, parts come and go, jumpers build into a tangled mess, but it’s all worth it when the circuit finally comes to life. Then comes the “What have I done?” phase, where you’ve got to backtrack through the circuit to document exactly how you built it. If only there was a better way.

Thanks to [Nick Bild], there is, in the form of the “Schematic-o-matic”, which aims to automate the breadboard documentation process. The trick is using a breadboard where each bus bar is connected to an IO pin on an Arduino Due. A program runs through each point on the breadboard, running a continuity test to see if there’s a jumper connecting them. A Python program then uses the connection list, along with some basic information about where components are plugged into the board, to generate a KiCad schematic.

[Nick] admits the schematics are crude at this point, and that it’s a bit inconvenient to remove some components, like ICs, from the breadboard first to prevent false readings. But this seems like one of those things where getting 80% of the work done automatically and worrying about the rest later is a big win. Plus, we can see a path forward to automatic IC probing, and even measurement of passive components too. But even as it is, it’s a great tool.

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Slick Keyboard Built With PCB Magic

Sometimes a chance conversation leads you to discover something cool you’ve not seen before, and before you know it, you’re ordering parts for yet another hardware build. That’s what happened to this scribe the other day when chatting on some random discord, to QMK maintainer [Nick Brassel aka tzarc] about Djinn, a gorgeous 64-key split mechanical keyboard testbed. It’s a testbed because it uses the newest STM32G4x microcontroller family, and QMK currently does not have support for this in the mainline release. For the time being, [Nick] maintains a custom release, until it gets merged.

Hardware-wise, the design is fabulous, with a lot of attention to detail. We have individual per-key RGB LEDs, RGB underglow, a rotary encoder, a five-way tactile thumb switch, and a 240×320 LCD per half. The keyboard is based on a three PCB stack, two of which are there purely for structure. This slick design has enough features to keep a fair few of us happy.

Interestingly, when you look at the design files (KiCAD, naturally) [Nick] has chosen to take a mirrored approach to the PCB. That means the left and right sides are actually the same PCB layout. The components are populated on different sides of the PCB depending on which half you’re looking at! By mirroring footprints on both PCB sides, and hooking everything up in parallel, it’s possible to do it all with a single master layout.

This is a simple but genius idea that this scribe hadn’t come across before (the shame!) Secondarily it keeps costs down, as your typical Chinese prototyping house will not deal in PCB quantities below five, so you can make two complete keyboards on one order, rather than needing two orders to make five. (Yes, there are actually three unique PCBs, but we’re simplifying the situation, ok?)

Now, if only this pesky electronics shortage could abate a bit, and we could get the parts to build this beauty!

Obviously, we’ve covered many, many keyboards over the years. Here’s our own [Kristina’s] column all about the things. If you need a little help with your typing skills, this shocking example may be the one for you. If your taste is proper old-school clackers, there’s something for everyone.

Flip-Chip KiCad Templates

We like retro-computing and we like open source standards that allow easy project sharing. Vintage DEC computer enthusiast [Jay Logue] combines both of these in his recent project on GitHub, where he shares several KiCad templates for making your own Flip-Chip modules. Although named after the semiconductor packaging technique we are familiar with today, DEC Flip-Chips were introduced in 1964 as a modular electronics packaging system. These were used in many of DEC’s Programmable Data Processor (PDP) computers, beginning with the PDP-8 in 1965. DEC also had a Digital Laboratory Module family, which was a roll-your-own custom electronic system. The 1968 Digital Logic Handbook shows the available modules, and has the look and feel of the TTL Cookbook book which would come along six years later.

Flip-Chips came in a variety of sizes over the years: single-, double-, and quad-, and hex-height boards having standard- and extended-length. The PCB’s have 18 gold-plated fingers on one edge, later extended to 36 fingers double-sided, which plug into a backplane. Interconnections were typically wire-wrapped. A single height board is 127 x 62 mm (5 x 2-7/16 inches) with a labeled extractor bracket on one end. [Jay]’s repository has templates for five of the most popular variations, and making other sizes should be straightforward using these templates as a starting point.

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3D Printed Printing Plates Made Using Modern Tools

It’s widely accepted that the invention of the printing press by Gutenberg in the 15th Century was the event that essentially enabled the development of the modern world, allowing access to knowledge beyond anything that came before, even if the Chinese got in on the bookmaking act some 500 years previously. Fast-forward a few centuries more and we’ve got the ability to design electronics from our arm chairs, we can print 3D objects from a machine on the coffee table, and 3D modeling can be done by your kids on a tablet computer. What a time to be alive! So we think it’s perfectly fine that [Kris Slyka] has gone full circle and used all these tools to make printing plates for a small press, in order to produce cards for her Etsy business.

Now before you scoff, yes she admits quite quickly that KiCAD wasn’t the best choice for designing the images to print, since she needed to do a lot of post-processing in Inkscape, she could have just dropped the first step and started in Inkscape anyway. You live and learn. Once the desired image was fully vectorised, it was popped into OpenSCAD in order to extrude it into 3D, thickening the contact to the base to improve the strength a little.

[Kris] demonstrates using the registration marks to align the front and rear side plates, and even (mostly) manages adding a second colour infill for a bit more pizzazz. The results look a little bit wonky and imperfect, exactly what you want for something supposed to be handmade. We think it’s a nice result, even if designing it in KiCAD was a bit bonkers.

For those interested in the OpenSCAD code, have a butchers at this gist. This project is not the first 3D-printed printing press we’ve covered, checkout the Hi-Bred for an example, and here’s the Open Press Project if you’re still interested.

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an image of kicad's homepage

KiCad Team Releases Warning Regarding Domain Name

On October 19th, [Seth_h] from the KiCad Project posted on the KiCad forums that the project’s original domain name kicad-pcb.org has been unexpectedly sold to a third party, and urged members of the community to avoid any links to this old website.

KiCad has used the domain kicad-pcb.org since 2012 as the official source for information on and downloads of their popular open-source electronics design software. Unfortunately, the original domain name was purchased before KiCad was formalized as an organization, so it was not directly under their control. This all came to head when the old domain name was unexpectedly sold to an unnamed third party that was not affiliated with the project. Currently, the old domain is just a website covered in ads, but the KiCad team fears that it may be used maliciously in the future.

With KiCad’s popularity, thousands of tutorials, articles, and project guides over the years have included links to the old KiCad domain. A Google search in October 2021 found more than 19,000 instances of the old domain spread across the internet. [Seth_h] has called upon the community to make every effort possible to update old links, reducing the chance that people stumble across the wrong website.

[Editor’s Note: We think we got ’em all, let us know if we missed any.]

Luckily, Digikey has swooped in to help save the day. They purchased a new domain, kicad.org, from squatters and donated it to the KiCad Project. (Update: Digi-key donated the KiCad.org domain back in October of 2020 after noticing fishy squatters going back to at least 2016) [Seth_h] explains in his post that a number of safeguards have been put in place to prevent this from happening in the future, including not having the domain name owned by a single person, and having all KiCad trademarks registered to the Linux Foundation.

There’s a good reason why KiCad has gotten so popular, it is packed full of great features for PCB design. Check out our coverage of some of the new features we are most excited for in KiCad 6.0 here.

Highly Configurable Open Source Microscope Cooked Up In FreeCAD

What do you get when you cross a day job as a Medical Histopathologist with an interest in 3D printing and programming? You get a fully-baked Open Source microscope, specifically the Portable Upgradeable Modular Affordable (or PUMA), that’s what. And this is no toy microscope. By combining a sprinkle of off-the-shelf electronics available from pretty much anywhere, a pound or two of filament, and a dash of high quality optical parts, PUMA cooks up quite possibly one of the best open source microscopy experiences we’ve ever tasted.

GitHub user [TadPath] works as a medical pathologist and clearly knows a thing or two about what makes a great instrument, so it is a genuine joy for us to see this tasty project laid out in such a complete fashion. Many a time we’ve looked into an high-profile project, only to find a pile of STL files and some hard to source special parts. But not here. This is deliberately designed to be buildable by practically anyone with access to a 3D printer and an eBay account.

The project is not currently certified for medical diagnostics use, but that is likely only a matter of money and time. The value for education and research (especially in developing nations) cannot really be overstated.

A small selection of the fixed and active aperture choices

The modularity allows a wide range of configurations from simple ambient light illumination, with a single objective, great for using out in the field without electricity, right up to a trinocular setup with TFT-based spatial light modulator enabling advanced methods such as Schlieren phase contrast (which allows visualisation of fluid flow inside a live cell, for example) and a heads-up display for making measurements from the sample. Add into the mix that PUMA is specifically designed to be quickly and easily broken down in the field, that helps busy researchers on the go, out in the sticks.

The GitHub repo has all the details you could need to build your own configuration and appropriate add-ons, everything from CAD files (FreeCAD source, so you can remix it to your heart’s content) and a detailed Bill-of-Materials for sourcing parts.

We covered fluorescence microscopy before, as well as many many other microscope related stories over the years, because quite simply, microscopes are a very important topic. Heck, this humble scribe has a binocular and a trinocular microscope on the bench next to him, and doesn’t even consider that unusual. If you’re hungry for an easily hackable, extendable and cost-effective scope, then this may be just the dish you were looking for.

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Tool Generates Interactive PCB Diagrams From KiCAD

Nearly everyone likes nice pinout diagrams, but the more pins and functions are involved, the more cluttered and less useful the diagram becomes. To address this, [Jan Mrázek] created Pinion, a tool to help generate interactive diagrams from KiCad design files.

The result is an interactive diagram that can be viewed in any web browser. Hovering over a pin or pad highlights those signals with a callout for the name, and clicking makes it stay highlighted for easier reference. Further information can be as detailed or as brief as needed.

Interestingly, Pinion isn’t a web service that relies on any kind of backend. The diagrams are static HTML and JavaScript only, easily included in web pages or embedded in GitHub documentation.

If you think Pinion looks a bit familiar, you’re probably remembering that we covered [Jan]’s much earlier PcbDraw tool, which turned KiCad board files into SVG renderings but had no ability to add labels or interactivity. Pinion is an evolution of that earlier idea, and its diagrams are able to act as both documentation and interactive reference, with no reliance on any kind of external service.

Interested? Pinion has a full tutorial and demo and a growing library of parts, so check it out.