Author: Lewin Day

3208 Articles

Quantum Random Number Generator Squirts Out Numbers Via MQTT

April 26, 2025 by 23 Comments

Sometimes you need random numbers — and properly random ones, at that. Hackaday Alum [Sean Boyce] whipped up a rig that serves up just that, tasty random bytes delivered fresh over MQTT.

[Sean] tells us he’s been “designing various quantum TRNGs for nearly 15 years as part of an elaborate practical joke” without further explanation. We won’t query as to why, and just examine the project itself. The main source of randomness — entropy, if you will — is a pair of transistors hooked up to create a bunch of avalanche noise that is apparently truly random, much like the zener diode method.

In any case, the noise from the transistors is then passed through a bunch of hex inverters and other supporting parts to shape the noise into a nicely random square wave. This is sampled by an ATtiny261A acting as a Von Neumann extractor, which converts the wave into individual bits of lovely random entropy. These are read by a Pi Pico W, which then assembles random bytes and pushes them out over MQTT.

Did that sound like a lot? If you’re not in the habit of building random number generators, it probably did. Nevertheless, we’ve heard from [Sean] on this topic before. Feel free to share your theories on the best random number generator designs below, or send your best builds straight to the tipsline. Randomly, of course!

Amazing Oscilloscope Demo Scores The Win At Revision 2025

April 26, 2025 by 34 Comments

Classic demos from the demoscene are all about showing off one’s technical prowess, with a common side order of a slick banging soundtrack. That’s precisely what [BUS ERROR Collective] members [DJ_Level_3] and [Marv1994] delivered with their prize-winning Primer demo this week.

This demo is a grand example of so-called “oscilloscope music”—where two channels of audio are used to control an oscilloscope in X-Y mode. The sounds played determine the graphics on the screen, as we’ve explored previously.

The real magic is when you create very cool sounds that also draw very cool graphics on the oscilloscope. The Primer demo achieves this goal perfectly. Indeed, it’s intended as a “primer” on the very artform itself, starting out with some simple waveforms and quickly spiraling into a graphical wonderland of spinning shapes and morphing patterns, all to a sweet electronic soundtrack. It was created with a range of tools, including Osci-Render and apparently Ableton 11, and the recording performed on a gorgeous BK Precision Model 2120 oscilloscope in a nice shade of green.

If you think this demo is fully sick, you’re not alone. It took out first place in the Wild category at the Revision 2025 demo party, as well as the Crowd Favorite award. High praise indeed.

We love a good bit of demoscene magic around these parts.

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Robot Gets A DIY Pneumatic Gripper Upgrade

April 25, 2025 by 2 Comments

[Tazer] built a small desktop-sized robotic arm, and it was more or less functional. However, he wanted to improve its ability to pick things up, and attaching a pneumatic gripper seemed like the perfect way to achieve that. Thus began the build!

The concept of [Tazer]’s pneumatic gripper is simple enough. When the pliable silicone gripper is filled with air, the back half is free to expand, while the inner section is limited in its expansion thanks to fabric included in the structure. This causes the gripper to deform in such a way that it folds around as it fills with air, which lets it pick up objects. [Tazer] designed the gripper so that that could be cast in silicone using 3D printed molds. It’s paired with a 3D printed manifold which delivers air to open and close the gripper as needed. Mounted on the end of [Tazer]’s robotic arm, it’s capable of lifting small objects quite well.

It’s a fun build, particularly for the lovely sounds of silicone parts being ripped out of their 3D printed molds. Proper ASMR grade stuff, here. We’ve also seen some other great work on pneumatic robot grippers over the years.

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Adding An Atari Joystick Port To TheC64 USB Joystick

April 24, 2025 by 1 Comment

“TheC64” is a popular recreation of the best selling computer of all time, the original Commodore 64. [10p6] enjoys hacking on this platform, and recently whipped up a new mod — adding a 9-pin Atari joystick connector for convenience.

When it comes to TheC64 units, they ship with joysticks that look retro, but aren’t. These joysticks actually communicate with the hardware over USB. [10p6]’s hack was to add an additional 9-pin Atari joystick connector into the joystick itself. It’s a popular mod amongst owners of TheC64 and the C64 Mini. All one needs to do is hook up a 9-pin connector to the right points on the joystick’s PCB. Then, it effectively acts as a pass-through adapter for hooking up other joysticks to the system.

While this hack could have been achieved by simply chopping away at the plastic housing of the original joystick, [10p6] went a tidier route. Instead, the joystick was granted a new 3D printed base that had a perfect mounting spot for the 9-pin connector. Clean!

We’ve seen some great hacks from [10p6] lately, like the neat reimagined “C64C” build that actually appears in this project video, too.

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3D Printing A Useful Fixturing Tool

April 24, 2025 by 14 Comments

When you start building lots of something, you’ll know the value of accurate fixturing. [Chris Borge] learned this the hard way on a recent mass-production project, and decided to solve the problem. How? With a custom fixturing tool! A 3D printed one, of course.

Chris’s build is simple enough. He created 3D-printed workplates covered in a grid of specially-shaped apertures, each of which can hold a single bolt. Plastic fixtures can then be slotted into the grid, and fastened in place with nuts that thread onto the bolts inserted in the base. [Chris] can 3D print all kinds of different plastic fixtures to mount on to the grid, so it’s an incredibly flexible system.

3D printing fixtures might not sound the stoutest way to go, but it’s perfectly cromulent for some tasks. Indeed, for [Chris]’s use case of laser cutting, the 3D printed fixtures are more than strong enough, since the forces involved are minimal. Furthermore, [Chris] aided the stability of the 3D-printed workplate by mounting it on a laser-cut wooden frame filled with concrete. How’s that for completeness?

We’ve seen some other great fixturing tools before, too. Video after the break.

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Onkyo Receiver Saved With An ESP32

April 24, 2025 by 23 Comments

[Bill Dudley] had a problem. He had an Onkyo AV receiver that did a great job… until it didn’t. A DSP inside failed. When that happened, the main microprocessor running the show decided it wouldn’t play ball without the DSP operational. [Bill] knew the bulk of the audio hardware was still good, it was just the brains that were faulty. Thus started a 4-month operation to resurrect the Onkyo receiver with new intelligence instead.

[Bill’s] concept was simple. Yank the dead DSP, and the useless microprocessor as well. In their place, an ESP32 would be tasked with running things. [Bill] no longer cared if the receiver had DSP abilities or even the ability to pass video—he just wanted to use it as the quality audio receiver that it was.

His project report steps through all the hard work he went through to get things operational again. He had to teach the ESP32 to talk to the front panel display, the keys, and the radio tuner. More challenging was the core audio processor—the obscure Renaisys R2A15218FP. However, by persevering, [Bill] was able to get everything up and running, and even added some new functionality—including Internet radio and Bluetooth streaming.

It’s a heck of a build, and [Bill] ended up with an even more functional audio receiver at the end of it all. Bravo, we say. We love to see older audio gear brought back to life, particularly in creative ways. Meanwhile, if you’ve found your own way to save a piece of vintage audio hardware, don’t hesitate to let us know!

Making Parts Feeders Work Where They Weren’t Supposed To

April 15, 2025 by 21 Comments

[Chris Cecil] had a problem. He had a Manncorp/Autotronik MC384V2 pick and place, and needed more feeders. The company was reluctant to support an older machine and wanted over $32,000 to supply [Chris] with more feeders. He contemplated the expenditure… but then came across another project which gave him pause. Could he make Siemens feeders work with his machine?

It’s one of those “standing on the shoulders of giants” stories, with [Chris] building on the work from [Bilsef] and the OpenPNP project. He came across SchultzController, which could be used to work with Siemens Siplace feeders for pick-and-place machines. They were never supposed to work with his Manncorp machine, but it seemed possible to knit them together in some kind of unholy production-focused marriage. [Chris] explains how he hooked up the Manncorp hardware to a Smoothieboard and then Bilsef’s controller boards to get everything working, along with all the nitty gritty details on the software hacks required to get everything playing nice.

For an investment of just $2,500, [Chris] has been able to massively expand the number of feeders on his machine. Now, he’s got his pick and place building more Smoothieboards faster than ever, with less manual work on his part.

We feature a lot of one-off projects and home production methods, but it’s nice to also get a look at methods of more serious production in bigger numbers, too. It’s a topic we follow with interest. Video after the break.

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