how-to

864 Articles

Hardware hacking how-tos

GPS And Its Little Modules

September 8, 2025 by 4 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.

Continue reading “GPS And Its Little Modules” →

Debugging The Instant Macropad

August 25, 2025 by No comments

Last time, I showed you how to throw together a few modules and make a working macropad that could act like a keyboard or a mouse. My prototype was very simple, so there wasn’t much to debug. But what happens if you want to do something more complex? In this installment, I’ll show you how to add the obligatory blinking LED and, just to make it interesting, a custom macro key.

There is a way to print data from the keyboard, through the USB port, and into a program that knows how to listen for it. There are a few choices, but the qmk software can do it if you run it with the console argument.

The Plan

In theory, it is fairly easy to just add the console feature to the keyboard.json file:

{
...
    "features": {
        "mousekey": true,
        "extrakey": true,
        "nkro": false,
        "bootmagic": false,
        "console": true
    },
...

That allows the console to attach, but now you have to print.

Continue reading “Debugging The Instant Macropad” →

Instant Macropad: Just Add QMK

August 20, 2025 by 2 Comments

I recently picked up one of those cheap macropads (and wrote about it, of course). It is surprisingly handy and quite inexpensive. But I felt bad about buying it. Something like that should be easy to build yourself. People build keyboards all the time now, and with a small number of keys, you don’t even have to scan a matrix. Just use an I/O pin per switch.

The macropad had some wacky software on it that, luckily, people have replaced with open-source alternatives. But if I were going to roll my own, it would be smart to use something like QMK, just like a big keyboard. But that made me wonder, how much trouble it would be to set up QMK for a simple project. Spoiler: It was pretty easy.

The Hardware

Simple badge or prototype macropad? Why not both?

Since I just wanted to experiment, I was tempted to jam some switches in a breadboard along with a Raspberry Pi Pico. But then I remembered the “simple badge” project I had up on a nearby shelf. It is simplicity itself: an RP2040-Plus (you could just use a regular Pi Pico) and a small add-on board with a switch “joystick,” four buttons, and a small display. You don’t really need the Plus for this project since, unlike the badge, it doesn’t need a battery. The USB cable will power the device and carry keyboard (or even mouse) commands back to the computer.

Practical? No. But it would be easy enough to wire up any kind of switches you like. I didn’t use the display, so there would be no reason to wire one up if you were trying to make a useful copy of this project.

Continue reading “Instant Macropad: Just Add QMK” →

Zine Printing Tips From A Solopreneur

July 25, 2025 by 28 Comments

Zines (self-produced, small-circulation publications) are extremely DIY, and therefore punk- and hacker-adjacent by nature. While they can be made with nothing more than a home printer or photocopier, some might benefit from professional production while losing none of their core appeal. However, the professional print world has a few gotchas, and in true hacker spirit [Mabel Wynne] shares things she learned the hard way when printing her solo art zine.

As with assembling hardware kits, assembling a zine can take up a lot of physical table space.

[Mabel] says the most useful detail to nail down before even speaking to printers is the zine’s binding, because binding type can impact layout and design of an entire document. Her advice? Nail it down early, whether it’s a simple saddlestitch (staples through a v-shaped fold of sheets), spiral binding (which allows a document to lay flat), or something else.

Aside from paper and print method (which may be more or less important depending on the zine’s content) the other thing that’s important to consider is the finishing. Finishing consists of things like cutting, folding, and binding of the raw printed sheets. A printer will help arrange these, but it’s possible to do some or even all of these steps for oneself, which is not only more hands-on but reduces costs.

Do test runs, and prototype the end result in order to force unknown problems to the surface before they become design issues. Really, the fundamentals have a lot in common with designing and building kits or hardware. Check out [Mabel]’s article for the full details; she even talks a little about managing money and getting a zine onto shelves.

Zine making is the DIYer’s way to give ideas physical form and put them into peoples’ hands more or less directly, and there’s something wonderfully and inherently subversive about that concept. 2600 has its roots in print, but oddball disk magazines prove one doesn’t need paper to make a zine.

Mini Car Racing Game Really Shows Off Multicolor Printing

July 16, 2025 by 12 Comments

Quality 3D printing is a common hobbyist tool nowadays, and [wontonnn]’s mini arcade car racing game really shows off how 3D printing can bring parts from functional to fantastic. There are quite a few details we like in [wontonn]’s design, so let’s take a closer look.

The mini mechanical game is one of those treadmill-based car racing games in which the player navigates a little car between an onslaught of belt-borne obstacles. A little DC motor spins things up in a modular side assembly, and a hand-cranked option is available. The player’s car attaches via a magnet to a steering arm; if the player’s car gets knocked off the magnet, game over.

Treadmill belt segments print as large pre-assembled pieces, with ends that snap together without connectors. Belts like this are sometimes tricky, so this is worth keeping in mind should one ever need a similar part. Since there are no external fasteners or hardware to depend on, one could resize it easily to suit their own project purposes.

The finishing touches on the whole assembly look great. It used to be that the sort of colors and lettering seen here would come from a sticker or label, but [wontonn] gets clean lines and colors by raising (or sinking) different parts of the design. The checkerboard pattern, for example, has the light squares raised for printing in a different color.

Electromechanical arcade games have an appeal all their own, being a fusion of both mechanical and electric design that comes together in a special way. Want to make your own? Get inspired by the classic Lunar Lander reimagined, or check out this LEGO treadmill racer that takes an entirely different approach to the concept.

Continue reading “Mini Car Racing Game Really Shows Off Multicolor Printing” →

Wire Like A Pro: Peeking Into Wire Harness Mastery

July 12, 2025 by 26 Comments

There are many ways to learn, but few to none of them compare to that of spending time standing over the shoulder of a master of the craft. This awesome page sent in by [JohnU] is a fantastic corner of the internet that lets us all peek over that shoulder to see someone who’s not only spent decades learning the art of of creating cable harnesses, but has taken the time to distill some of that vast experience for the rest of us to benefit from.

Wire bundle

This page is focused on custom automotive and motorcycle modifications, but it’s absolutely jam-packed with things applicable in so many areas. It points out how often automotive wiring is somewhat taken for granted, but it shouldn’t be; there are hundreds of lines, all of which need to work for your car to run in hot and cold, wet and dry. The reliability of wiring is crucial not just for your car, but much larger things such as the 530 km (330 mi) of wiring inside an Airbus A380 which, while a large plane, is still well under 100 m in length.

This page doesn’t just talk about cable harnessing in the abstract; in fact, the overwhelming majority of it revolves around the practical and applicable. There is a deep dive into wiring selection, tubing and sealing selection, epoxy to stop corrosion, and more. It touches on many of the most common connectors used in vehicles, as well as connectors not commonly used in the automotive industry but that possess many of the same qualities. There are some real hidden gems in the midst of the 20,000+ word compendium, such as thermocouple wiring and some budget environmental sealing options.

There is far more to making a thing beyond selecting the right parts; how it’s assembled and the tools used are just as important. This page touches on tooling, technique, and planning for a wire harness build-up. While there are some highly specialized tools identified, there are also things such as re-purposed knitting needles. Once a harness is fully assembled it’s not complete, as there is also a need for testing that must take place which is also touched on here.

Thanks to [JohnU] for sending in this incredible learning resource. If this has captured your attention like it has ours, be sure to check out some of the other wire harness tips we’ve featured!

Fingers installing a service loop in a wire in a connector

Are Service Loops A Good Idea?

July 1, 2025 by 23 Comments

Well, here’s an interesting idea: the service loop. Ever heard of it? We haven’t!

In the video, the presenter explains the service loop serves two purposes: on the one hand it may provide strain relief, but chiefly these loops are installed so there will be extra available slack in the cable if you need to rewire it some day to change the configuration of your pinout.

One major problem with the service loop may be that the single turn is enough to create an inductor which will then induce noise and cross-talk all over the place. Our rule of thumb is always to completely unroll wires and cables before using them. Do you have a theory about the benefits or problems with service loops? If you do, we’d love to hear what you think in the comments!

If you’re interested in strain relief, we’ve covered that before, and you don’t need a service loop to do it! Check out Cheap Strain Relief By Casting Hot Glue In A 3D Print and Arduino Uno Strain Relief.

Continue reading “Are Service Loops A Good Idea?” →