Author: Arya Voronova

495 Articles

FreeCAD Foray: Good Practices

September 11, 2025 by 26 Comments

Last time, we built a case for a PCB that handles 100 W of USB-C power, an old project that I’ve long been aiming to revive. It went well, and I’d like to believe you that the article will give you a much-needed easy-to-grasp FreeCAD introduction, Matrix knowledge upload style, having you designing stuff in no time.

Apart from my firm belief in the power of open-source software, I also do believe in social responsibilities, and I think I have a responsibility to teach you some decent FreeCAD design practices I’ve learned along the way. Some of them are going to protect your behind from mistakes, and some of them will do that while also making your project way easier to work with, for you and others.

You might not think the last part about “others” matters, but for a start, it matters in the ideal world that we’re collectively striving towards, and also, let’s be real, things like documentation are half intended for external contributors, half for you a year later. So, here’s the first FreeCAD tip that will unquestionably protect you while helping whoever else might work with the model later.

Okay, we’re all hackers, so I’ll start with zero-th FreeCAD tip – press Ctrl+S often. That’ll help a ton. Thankfully, FreeCAD’s autorecovery system has made big leaps, and it’s pretty great in case FreeCAD does crash, but the less you have to recover, the better. Now, onto the first tip.

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FreeCAD Foray: From Brick To Shell

September 9, 2025 by 18 Comments

Over a year ago, we took a look at importing a .step file of a KiCad PCB into FreeCAD, then placing a sketch and extruding it. It was a small step, but I know it’s enough for most of you all, and that brings me joy. Today, we continue building a case for that PCB – the delay is because I stopped my USB-C work for a fair bit, and lost interest in the case accordingly, but I’m reviving it now.

Since then, FreeCAD has seen its v 1.0 release come to fruition, in particular getting a fair bit of work done to alleviate one of major problems for CAD packages, the “topological naming problem”; we will talk about it later on. The good news is, none of my tutorial appears to have been invalidated by version 1.0 changes. Another good news: since version 1.0, FreeCAD has definitely become a fair bit more stable, and that’s not even including some much-needed major features.

High time to pick the work back up, then! Let’s take a look at what’s in store for today: finishing the case in just a few more extrusions, explaining a few FreeCAD failure modes you might encounter, and giving some advice on how to make FreeCAD for you with minimum effort from your side.

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GPS And Its Little Modules

September 8, 2025 by 17 Comments

Ever want to find your device on the map? Think we all do sometimes. The technology you’ll generally use for that is called Global Positioning System (GPS) – listening to a flock of satellites flying in the orbit, and comparing their chirps to triangulate your position.

The GPS system, built by the United States, was the first to achieve this kind of feat. Since then, new flocks have appeared in the orbit, like the Galileo system from the European Union, GLONASS from Russia, and BeiDou from China. People refer to the concept of global positioning systems and any generic implementation as Global Navigation Satellite System (GNSS), but I’ll call it GPS for the purposes of this article, and most if not all advice here will apply no matter which one you end up relying on. After all, modern GPS modules overwhelmingly support most if not all of these systems!

We’ve had our writers like [Lewin Day] talk in-depth about GPS on our pages before, and we’ve featured a fair few projects showing and shining light on the technology. I’d like to put my own spin on it, and give you a very hands-on introduction to the main way your projects interface with GPS.

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Design Review: LattePanda Mu NAS Carrier

August 12, 2025 by 17 Comments

It is a good day for design review! Today’s board is the MuBook, a Lattepanda Mu SoM (System-on-Module) carrier from [LtBrain], optimized for a NAS with 4 SATA and 2 NVMe ports. It is cheap to manufacture and put together, the changes are non-extensive but do make the board easier to assemble, and, it results in a decent footprint x86 NAS board you can even order assembled at somewhere like JLCPCB.

This board is based on the Lite Carrier KiCad project that the LattePanda team open-sourced to promote their Mu boards. I enjoy seeing people start their project from a known-working open-source design – they can save themselves lots of work, avoid reinventing the wheel and whole categories of mistakes, and they can learn a bunch of design techniques/tips through osmosis, too. This is a large part of why I argue everyone should open-source their projects to the highest extent possible, and why I try my best to open-source all the PCBs I design.

Let’s get into it! The board’s on GitHub as linked, already containing the latest changes.

Git’ting Better

I found the very first review item when downloading the repo onto my computer. It took a surprising amount of time, which led me to believe the repo contains a fair bit of binary files – something quite counterproductive to keep in Git. My first guess was that the repo had no .gitignore for KiCad, and indeed – it had the backups/ directory with a heap of hefty .zips, as well as a fair bit of stuff like gerbers and footprint/symbol cache files. I checked in with [LtBrain] that these won’t be an issue to delete, and then added a .gitignore from the Blepis project.

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Smartphone Hackability, Or, A Pocket Computer That Isn’t

August 11, 2025 by 86 Comments

Smartphones boggle my mind a whole lot – they’re pocket computers, with heaps of power to spare, and yet they feel like the furthest from it. As far as personal computers go, smartphones are surprisingly user-hostile.

In the last year’s time, even my YouTube recommendations are full of people, mostly millennials, talking about technology these days being uninspiring. In many of those videos, people will talk about phones and the ecosystems that they create, and even if they mostly talk about the symptoms rather than root causes, the overall mood is pretty clear – tech got bland, even the kinds of pocket tech you’d consider marvellous in abstract. It goes deeper than cell phones all looking alike, though. They all behave alike, to our detriment.

A thought-provoking exercise is to try to compare smartphone development timelines to those of home PCs, and see just in which ways the timelines diverged, which forces acted upon which aspect of the tech at what points, and how that impacted the alienation people feel when interacting with either of these devices long-term. You’ll see some major trends – lack of standardization through proprietary technology calling the shots, stifling of innovation both knowingly and unknowingly, and finance-first development as opposed to long-term investments.

Let’s start with a fun aspect, and that is hackability. It’s not perceived to be a significant driver of change, but I do believe it to be severely decreasing chances of regular people tinkering with their phones to any amount of success. In other words, if you can’t hack it in small ways, you can’t really make it yours.

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Hacker Tactic: ESD Diodes

June 19, 2025 by 24 Comments

A hacker’s view on ESD protection can tell you a lot about them. I’ve seen a good few categories of hackers neglecting ESD protection – there’s the yet-inexperienced ones, ones with a devil-may-care attitude, or simply those of us lucky to live in a reasonably humid climate. But until we’re able to control the global weather, your best bet is to befriend some ESD diodes before you get stuck having to replace a microcontroller board firmly soldered into your PCB with help of 40 through-hole pin headers.

Humans are pretty good at generating electric shocks, and oftentimes, you’ll shock your hardware without even feeling the shock yourself. Your GPIOs will feel it, though, and it can propagate beyond just the input/output pins inside your chip. ESD events can be a cause of “weird malfunctions”, sudden hardware latchups, chips dying out of nowhere mid-work – nothing to wish for.

Worry not, though. Want to build hardware that survives? Take a look at ESD diodes, where and how to add them, where to avoid them, and the parameters you want to keep in mind. Oh and, I’ll also talk about all the fancy ways you can mis-use ESD diodes, for good and bad alike!

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ZPUI Could Be Your Tiny Embedded GUI

June 18, 2025 by 17 Comments

One of the most frustrating things to me is looking at a freshly-flashed and just powered up single board computer. My goal with them is always getting to a shell – installing packages, driving GPIOs, testing my proof of concept code, adjusting the device tree to load peripheral drivers. Before I can do any of that, I need shell access, and getting there can be a real hassle.

Time after time, I’ve struggled trying to get to a shell on an SBC. For best results, you’d want to get yourself a keyboard, monitor, and an Ethernet cable. Don’t have those, or there’s no space to place them? Maybe a UART connection will work for you – unless it’s broken or misconfigured. Check your pinouts twice. Sure, nowadays you can put WiFi credentials into a text file in /boot/ – but good luck figuring out the IP address, or debugging any mistakes you might make formatting the file. Nowadays, Pi 4 and 5 expose a USB gadget connection on the USB-C port, and that helps… unless you’re already powering the Pi from that port. There’s really no shortage of failure modes here.

If you put a Pi on your network and it goes offline, you generally just don’t know what happened unless you reboot it, which can make debugging into a living hell. I’ve dealt with single-board computers mounted above fiberglass lifted ceilings, fleets of Pi boards at workshops I organized, pocket-carried Pi boards, and at some point, I got tired of it all. A hacker-aimed computer is meant to be accessible, not painful.

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