Multifunctional USB controlled PCB on blue background

How A Tiny Relay Became A USB Swiss Army Knife

April 5, 2025 by 2 Comments

Meet the little board that could: [alcor6502]’s tiny USB relay controller, now evolved into a multifunction marvel. Originally built as a simple USB relay to probe the boundaries of JLCPCB’s production chops, it has become a compact utility belt for any hacker’s desk drawer. Not only has [alcor6502] actually built the thing, he even provided intstructions. If you happened to be at Hackaday in Berlin, you now might even own one, as he handed out twenty of them during his visit. If not, read on and build it yourself.

This thing is not just a relay, and that is what makes it special. Depending on a few solder bridges and minimal components, it shape-shifts into six different tools: a fan controller (both 3- and 4-pin!), servo driver, UART interface, and of course, the classic relay. It even swaps out a crystal oscillator for USB self-sync using STM32F042‘s internal RC – no quartz, less cost, same precision. A dual-purpose BOOT0 button lets you flash firmware and toggle outputs, depending on timing. Clever reuse, just like our mothers taught us.

It’s the kind of design that makes you want to tinker again. Fewer parts. More function. And that little smile when it just works. If this kind of clever compactness excites you too, read [alcor6502]’s build log and instructions here.

If You’re 3D Scanning, You’ll Want A Way To Work With Point Clouds

April 5, 2025 by 4 Comments

3D scanning is becoming much more accessible, which means it’s more likely that the average hacker will use it to solve problems — possibly odd ones. That being the case, a handy tool to have in one’s repertoire is a way to work with point clouds. We’ll explain why in a moment, but that’s where CloudCompare comes in (GitHub).

Not all point clouds are destined to be 3D models. A project may call for watching for changes in a surface, for example.

CloudCompare is an open source tool with which one can load up and do various operations on point clouds, including generating mesh models from them. Point clouds are what 3D scanners create when an object is scanned, and to become useful, those point clouds are usually post-processed into 3D models (specifically, meshes) like an .obj or .stl file.

We’ve gone into detail in the past about how 3D scanning works, what to expect from it, and taken a hands-on tour of what an all-in-one wireless scanner can do. But what do point clouds have to do with getting the most out of 3D scanning? Well, if one starts to push the boundaries of how and to what purposes 3D scanning can be applied, it sometimes makes more sense to work with point clouds directly instead of the generated meshes, and CloudCompare is an open-source tool for doing exactly that.

For example, one may wish to align and merge two or more different clouds, such as from two different (possibly incomplete) scans. Or, you might want to conduct a deviation analysis of how those different scans have changed. Alternately, if one is into designing wearable items, it can be invaluable to be able to align something to a 3D scan of a body part.

It’s a versatile tool with numerous tutorials, so if you find yourself into 3D scanning but yearning for more flexibility than you can get by working with the mesh models — or want an alternative to modeling-focused software like Blender — maybe it’s time to work with the point clouds directly.

A Look Inside MacPaint

April 5, 2025 by 12 Comments

Usually when we talk about retrocomputing, we want to look at — and in — some old hardware. But [Z→Z] has a different approach: dissecting MacPaint, the Apple drawing program from the 1980s.

While the program looks antiquated by today’s standards, it was pretty hot stuff back in the day. Things we take for granted today were big deals at the time. For example, being able to erase a part of something you drew prompted applause at an early public demo.

We enjoyed the way the program was tested, too. A software “monkey” was made to type keys, move things, and click menus randomly. The teardown continues with a look inside the Pascal and assembly code with interesting algorithms like how the code would fill an area with color.

The program has been called “beautifully organized,” and [Z→Z] examines that assertion. Maybe the brilliance of it has been overstated, but it did work and it did influence many computer graphics programs over the years.

We love digging through old source code. Even old games. If you do your own teardowns, be sure to send us a tip.

Disney’s Bipedal, BDX-Series Droid Gets The DIY Treatment

April 5, 2025 by No comments

[Antoine Pirrone] and [Grégoire Passault] are making a DIY miniature re-imagining of Disney’s BDX droid design, and while it’s still early, there is definitely a lot of progress to see. Known as the Open Duck Mini v2 and coming in at a little over 40 cm tall, the project is expected to have a total cost of around 400 USD.

The inner workings of Open Duck Mini use a Raspberry Pi Zero 2W, hobby servos, and an absolute-orientation IMU.

Bipedal robots are uncommon, and back in the day they were downright rare. One reason is that the state of controlled falling that makes up a walking gait isn’t exactly a plug-and-play feature.

Walking robots are much more common now, but gait control for legged robots is still a big design hurdle. This goes double for bipeds. That brings us to one of the interesting things about the Open Duck Mini v2: computer simulation of the design is playing a big role in bringing the project into reality.

It’s a work in progress but the repository collects all the design details and resources you could want, including CAD files, code, current bill of materials, and links to a Discord community. Hardware-wise, the main work is being done with very accessible parts: Raspberry Pi Zero 2W, fairly ordinary hobby servos, and an BNO055-based absolute orientation IMU.

So, how far along is the project? Open Duck Mini v2 is already waddling nicely and can remain impressively stable when shoved! (A “testing purposes” shove, anyway. Not a “kid being kinda mean to your robot” shove.)

Check out the videos to see it in action, and if you end up making your own, we want to hear about it, so remember to send us a tip!

8 Pins For Linux

April 5, 2025 by 18 Comments

We’ve seen a Linux-based operating system made to run on some widely varying pieces of hardware over the years, but [Dimity Grinberg]’s latest project may be one of the most unusual. It’s a PCB with 3 integrated circuits on it which doesn’t seem too interesting at first, but what makes it special is that all three of those chips are in 8-pin SOIC packages. How on earth can Linux run on 8-pin devices? The answer lies as you might expect, in emulation.

Two of the chips are easy to spot, a USB-to-serial chip and an SPI RAM chip. The processor is an STM32G0 series device, which packs a pretty fast ARM Cortex M0+ core. This runs a MIPS emulator that we’ve seen on a previous project, which is ripe for overclocking. At a 148 MHz clock it’s equivalent to a MIPS running at about 1.4 MHz, which is just about usable. Given that the OS in question is a full-featured Debian, it’s not running some special take on Linux for speed, either.

We like some of the hardware hacks needed to get serial, memory, and SD card, onto so few pins. The SD and serial share the same pins, with a filter in place to remove the high-frequency SPI traffic from the low-frequency serial traffic. We’re not entirely sure what use this machine could be put to, but it remains an impressive piece of work.

Lockdown Remote Control Project Is Free And Open

April 4, 2025 by 5 Comments

If you flew or drove anything remote controlled until the last few years, chances are very good that you’d be using some faceless corporation’s equipment and radio protocols. But recently, open-source options have taken over the market, at least among the enthusiast core who are into squeezing every last bit of performance out of their gear. So why not take it one step further and roll your own complete system?

Apparently, that’s what [Malcolm Messiter] was thinking when, during the COVID lockdowns, he started his own RC project that he’s calling LockDownRadioControl. The result covers the entire stack, from the protocol to the transmitter and receiver hardware, even to the software that runs it all. The 3D-printed remote sports a Teensy 4.1 and off-the-shelf radio modules on the inside, and premium FrSky hardware on the outside. He’s even got an extensive folder of sound effects that the controller can play to alert you. It’s very complete. Heck, the transmitter even has a game of Pong implemented so that you can keep yourself amused when it’s too rainy to go flying.

Of course, as we alluded to in the beginning, there is a healthy commercial infrastructure and community around other open-source RC projects, namely ExpressLRS and OpenTX, and you can buy gear that runs those software straight out of the box, but it never hurts to have alternatives. And nothing is easier to customize and start hacking on than something you built yourself, so maybe [Malcolm]’s full-stack RC solution is right for you? Either way, it’s certainly impressive for a lockdown project, and evidence of time well spent.

Thanks [Malcolm] for sending that one in!

The Transputer In Your Browser

April 4, 2025 by 9 Comments

We remember when the transputer first appeared. Everyone “knew” that it was going to take over everything. Of course, it didn’t. But [Oscar Toledo G.] gives us a taste of what life could have been like with a JavaScript emulator for the transputer, you can try in your browser.

If you don’t recall, the transputer was a groundbreaking CPU architecture made for parallel processing. Instead of giant, powerful CPUs, the transputer had many simple CPUs and a way to chain them all together. Sounds great, but didn’t quite make it. However, you can see the transputer’s influence on CPUs even today.

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