Study Hacker History, And Update It

March 18, 2023 by Elliot Williams 8 Comments

Looking through past hacks is a great source of inspiration. This week, we saw [Russ Maschmeyer] re-visiting a classic hack by [Jonny Lee] that made use of a Wiimote’s IR camera to fake 3D, or at least provide a compelling parallax effect that’ll fool your brain, without any expensive custom hardware.

[Lee]’s original demo was stunning, and that alone is reason to revisit it. Using the Wiimote as the webcam was inspired back in 2007, because it meant that there was no hard computer vision work to be done in estimating the viewer’s position – the camera only sees IR LEDs anyway. The tradeoff is that you had to wear two IR LEDs on your head, calibrate it just right, and that only the person with the headset on gets the illusion just right.

This is why re-visiting the past can be fruitful. As [Russ] discovered, computing power is so plentiful these days that you could do face/eye position estimation with a normal webcam easier than you could source an old Wiimote. Indeed, he’s getting the positioning so accurate that he’s worried about to which eye he’s projecting the illusion. Clearly, it’s time for a revamp.

So here’s the formula: find a brilliant old hack, and notice if it was hampered by the state of technology back when it was done. Update this using modern conveniences, and voila! You might just find that you can take the idea further, simply because you have more tools in your toolbox. Nothing wrong with standing on the shoulders of giants.

But beware! Time isn’t sitting still for you either. As soon as you make your killer 3D vision hack, VR goggles will become cheap and ubiquitous. So get it done today, before your hack becomes inspiration for the future.

Meet The New Moteus BLDC Controller Board, The N1

March 18, 2023 by Chris Lott 4 Comments

[Josh] over at mjbots just released a new version of the moteus controller board, dubbed the moteus-n1. One change is that the volume and footprint size has been reduced. Considering many people, [Josh] included, use these controllers to operate robotic dogs, smaller is better. The previous moteus controller maxed out at 44 V, but the n1 can run at up to 54 V, allowing use of 48 V power supplies. And [Josh] improved the interface circuitry, making it much more flexible than before. This comes at an increased price, but he sells both versions — parts availability permitting. And like the previous versions of the moteus controller, this is an open source project and you’re free to build it yourself. You can check out the complete design package at the project’s GitHub repository.

One helpful point is that the firmware for the n1 is the same, it simply enables new features related to the I/O ports. This means a user could swap in a new controller with no impact to their system. Maintaining firmware compatibility was just one of the challenges [Josh] faced along the way. Squeezing additional functionality into the small number of user-exposed I/O pins was a chore, but dealing with supply chain issues was a big headache:

…make a revision that leveraged the parts I had, along with ensuring that the parts I needed were achievable to purchase in a reasonable time frame. Some parts orders for this batch were placed nearly a year ago.

Check out moteus if you need a brushless servo controller. We covered the previous major upgrade last year, which was primarily firmware and interface focused.

DOOM Ported To A Single LEGO Brick

March 18, 2023 by Lewin Day 18 Comments

By now you’ve all seen the tiny LEGO brick with a working screen in it. The work of one [James “Ancient” Brown], it was truly a masterpiece of miniaturization and creativity. Since then, [James] hasn’t stopped innovating. Now, he’s demoing a playable version of DOOM running on a single plastic brick.

We’ve covered the construction of these astounding screen bricks before. Long story short, [James] designed a tiny PCB that hosts an RP2040 microcontroller which is then hooked up to a tiny OLED screen. The components are placed in a silicone mold, which is then filled with transparent resin to form the brick. The screen is then powered via contacts in the bottom, much like older-style LEGO motors.

Early experiments involved running various graphics to emulate a spaceship dashboard, but [James] has now gone much further. He’s implemented RP2040-doom to run the game. It uses tilt controls thanks to an accelerometer, combined with capacitive touch controls for shooting. The monochrome OLED is driven very fast with a special library of [James’] own creation to create three levels of grayscale to make the game actually visible and (just barely) playable.

It’s a hack, of course, and the controls are far from perfect. Nobody’s speed-running E1M1 on [James’s] LEGO brick, to be sure. Perchance. With that said, it’s still a glorious piece of work nonetheless. Just imagine, sitting with friends, and announcing you’re going to play some DOOM — only to pluck a piece of LEGO out of your pocket and start blasting away at demons.

Just because [James] doesn’t know when to quit, we’re going to lay down the gauntlet. Let’s get network play happening on these things, yeah?
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HP 3488A Teardown, Dismantled For Parts

March 17, 2023 by Chris Lott 10 Comments

[IMSAI Guy] has an old HP 3488A Switch Control Unit that he wants to dismantle for parts ( see video below the break ). The 3488A is pretty simple as far as HP test equipment goes — a chassis that can hold various types of relay cards and is programmable over GPIB. He notes up front that these are plentiful and inexpensive in the used test equipment market. Continue reading “HP 3488A Teardown, Dismantled For Parts” →

The Blue Soup Saga Is One Beefy Mystery

March 17, 2023 by Lewin Day 38 Comments

Beef soup! You’d normally expect it to be somewhere from reddish-brown to grey, depending on how well it was cooked and prepared. However, strangely, an assistant professor found the beef soup in their fridge had mysteriously turned blue. That spawned an investigation into the cause which is still ongoing.

[Dr. Elinne Becket] has earned her stripes in microbiology, but the blue soup astounded her. Despite her years of experience, she was unable to guess at the process or a source of contamination that could turn the soup blue. Indeed, very few natural foods are blue at all. Even blueberries themselves are more of a purple color. The case sparked enough interest that [Elinne] went back to the trash to collect photos and sample for research at the request of others.

Thus far, metagenomic DNA analysis is ongoing and samples of the soup have been cultivated in petri dishes. Early analysis shows that some of the microbes form iridescent colonies, Another researcher is trying to determine if the bugs from the soup can make blue color appear on soft cheese. There’s some suspicion that a bacteria known as pseudomonas aeruginosa could be the cause of the blue color, but that presents its own problems. P. aeruginosa is classified as a Biosafety Level 2 pathogen which would require some researchers to abandon work on the project for safety reasons.

The jury’s still out on this microbiological mystery. If you’ve got some ideas on what could be going on, let us know in the comments!

Broken Pocket Watch Becomes Pocket Sundial

March 17, 2023 by Lewin Day 9 Comments

Pocket watches are all well and good, but they have some caveats. They either need regular rewinding, or they need batteries. Sundials on the other hand need only the light from our One True Sun. [JGJMatt] has just the project to convert your broken or disused pocket watches to the solar way of telling the time.

The key is to replace the clockwork internals and face of the pocket watch with a sundial instead. The first step is to create a face for the watch marked out for sundial use. [JGJMatt] explains how to do this with a variety of CNC, painting, or etching methods. He also explains how to use simple tools to generate a sundial design that’s ideally suited to your geographical location. This includes methods for aligning the sundial to True North or True South with an offset compared to Magnetic North or Magnetic South. This allows the sundial to be as accurate as possible. [JGJMatt] describes the general techniques while also building a sundial of his very own. The resulting piece is a handsome bit of brass with a lovely gnomon standing tall to cast a shadow on the dial.

It’s not a quick way to tell the time, by any means. However, the next time your friends ask you what time it is, and you whip out a compass to line up your sundial, they’re sure to be impressed. We’ve seen some creative sundial designs before, too, and if you’ve been creating your own fancy timepieces, don’t hesitate to let us know on the tipsline!

Finessing A Soldering Iron To Remove Large Connectors

March 17, 2023 by Bryan Cockfield 32 Comments

One of the first tools that is added to a toolbox when working on electronics, perhaps besides a multimeter, is a soldering iron. From there, soldering tools can be added as needed such as a hot air gun, reflow oven, soldering gun, or desoldering pump. But often a soldering iron is all that’s needed even for some specialized tasks as [Mr SolderFix] demonstrates.

This specific technique involves removing a large connector from a PCB. Typically either a heat gun would be used, which might damage the PCB, or a tedious process involving a desoldering tool or braided wick might be tried. But with just a soldering iron, a few pieces of wire can be soldered around each of the pins to create a massive solder blob which connects all the pins of the connector to this wire. With everything connected to solder and wire, the soldering iron is simply pressed into this amalgamation and the connector will fall right out of the board, and the wire can simply be dropped away from the PCB along with most of the solder.

There is some cleanup work to do afterwards, especially removing excess solder in the holes in the PCB, but it’s nothing a little wick and effort can’t take care of. Compared to other methods which might require specialized tools or a lot more time, this is quite the technique to add to one’s soldering repertoire. For some more advanced desoldering techniques, take a look at this method for saving PCBs from some thermal stresses.

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