2022 Sci-Fi Contest: Schrödinger’s Trigger Is Trained On Electrons, Not Cats

While it’s true that Hackaday scribes and their families are sadly unable to compete in our contests, Hackaday alum are more than welcome to throw their hat in the ring. [Legionlabs] even made a game of it — they used only parts from the scrap heap, and even played beat the clock to build a real, science-fictiony, working thing in eight hours or less.

Okay, cool, but what does it do? Well, put simply, a rising edge on the input drives one of two outputs, lighting one of two drool-worthy flanged LEDs. Which output will [alight] is unknowable until observed, thus the Schrodinger’s aspect. In practice, the output is determined by sampling. In this case, the sampling is of the time difference between three electron-tunneling events.

Stage one of Schrodinger’s Trigger is a pair of inputs — one variable 10-15 VDC input and 5 VDC input. Then comes the electron-tunneling event generator. [Legionlabs] is reverse-biasing a semiconductor junction (a 2N551 transistor). What does that mean? If we consider the junction as a diode and apply voltage in the wrong direction, what happens? At best, nothing; at worst, the smoke monster appears to admonish us.

But with a semiconductor acting as a diode, some electrons are bound to jump across the junction. This is known as tunneling, and is a useful phenomenon as it is purely random.

Stage three consists of amplifying the signal from these rebel electrons via hex inverters. Why not op-amps? The CD4069s were cheaper and within reach. Finally, the amplified signals are sampled with an ATtiny12, and some assembly logic figures out which LED to light.

It’s nice to see an entry that leans more toward the science side of things while winning aesthetically. We dig the nice ABS enclosure, and are totally envious of [Legionlabs]’ access to flanged LEDs and those glass table top mounting point discs in the corners.

An HP9830A opened up and running

The Epic Journey Of Repairing An HP 9830A Desktop Computer From The 1970s

We love our retrocomputers here at Hackaday, and we’re always delighted to see someone rescue an historic artefact from the landfill. Sometimes, all it takes is replacing a broken power switch or leaky capacitor; other times you need to bring out the oscilloscope and dig deeper into internal circuitry. But the huge amount of work [Jerry Walker] put into bringing an HP 9830A back on its feet is something you don’t see very often.

If you’re not familiar with the HP 9830A, it’s a desktop computer from the early 1970s, fully built from discrete logic gates. The machine on [Jerry]’s desk turned out to be completely dead, with not even the fan spinning up. This was caused by a dodgy power switch, but replacing that switch was just the beginning: there were several bad components inside the power supply as well as a huge amount of moist dirt on the back of the motherboard. After a thorough cleaning and the replacement of several failed components, all four power rails were running within spec again.

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PicoCat, printed in yellow filament, looking at you with its ultrasonic sensor eyes

Build Your Own Cat – Some Assembly Required

Robotic pets are sci-fi material, and [Kevin McAleer] from [Kev’s Robots] is moving us all ever so closer towards a brighter, happier, more robotic future. One of his latest robot builds, PicoCat, is a robot cat with servo-driven paws. It follows in the footsteps of the OpenCat project made by Dr. Rongzhong Li back in 2016, and we’re always happy seeing someone pick up where another hacker left off. [Kevin] took heavy inspiration from the OpenCat design – rebuilding it with hardware more friendly and accessible for makers today.

Projects like these, involving data processing and calculations to get the servos moving just right, stand to benefit from the computing power of recently released RP2040 MCU. As such, the Pimoroni Servo 2040 board is a crucial component of this build, being both the brains of the project and also a PIO-boosted driver for the eleven servos helping this robot come alive. This cat’s eyes are an ultrasonic sensor, and you can add a whole lot more sensors for any robotic intention of yours. Don’t expect this kitty to jump one meter high or scratch your favourite couch to death just yet, but there’s already a lot of potential, especially coupled with a small speaker.

A PicoCat with a non-robotic kitten in the backgroundDoes this robotic cat interest you, whether it’d be due to your sci-fi propensity or a cat hair allergy? You’re in luck, because [Kevin] is keeping things firmly in the “open-source everything” realm. MicroPython code is stored in a GitHub repo, STLs are in a .zip linked on the page, and there’s plenty of renders to never leave you confused on what goes where. With all these resources, you can source the servos and the boards, fire up your 3D printer and sit down to assemble your own PicoCat. But not just that, [Kevin] also recorded three whole streams with insights, giving us over four hours of how-it-came-to-be video material for us to learn from. First, two streams of him designing the PicoCat in Fusion360, and then, him talking about the way he creates unit tests in MicroPython to improve his robots’ reliability and significantly reduce the amount of bugs cropping up.

This is not the last we will hear from [Kevin]’s robot-filled workshop, and previously, we’ve covered his Cray-1-shaped Pi Zero cluster system and a Raspberry Pi theremin, both as open and reproducible as this kitty! As you assemble yourself a PicoCat, or perhaps a Stanford Pupper or any of the other lovely quadru-pets we’ve previously featured, you might wonder how to properly move the servos, and we’ve covered a project that teaches you specifically that.

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Ask Hackaday: Would A Scooter Get You Back To The Office?

So we’re two plus years into the pandemic at this point. Are you still working from home in the most comfortable clothes ever sewn? We figure that of the lot of you who said goodbye to that drab, tiled carpet in 2020, most have probably heard rumblings about returning to the office. And probably a good portion have at least been forced into a hybrid schedule.

Lots of companies would love to see their employees once again milling about all those glass and steel observation tanks office buildings they pay so much for. And while some are likely just forcing employees to come back, others are offering incentives, such as Google. The tech giant recently partnered with electric scooter manufacturer Unagi to provide a “Ride Scoot” program designed to lure many of Google’s US-based employees back to those brightly-colored code playgrounds they call offices with a fun mode of private transportation. The plan is to offer a full reimbursement of the monthly subscription fee for Unagi’s Model One folding scooter, which retails for $990.

The subscription is normally $49 a month plus a one-time $50 sign-up fee, but this amount will be slightly discounted (and waived) for eligible Google employees. There is one caveat to the system: an employee must use the scooter for a minimum of nine commutes to the office per month, although Google says they’re gonna be a bro about it and use the honor system.

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Movie Prop Electronics Hack Chat

Join us on Wednesday, April 20 at noon Pacific for the Movie Prop Electronics Hack Chat with Ben Eadie!

It wasn’t too long after the invention of cinema that the need for special effects became apparent. If you want to tell stories, especially the science fiction type of story, you need to build a plausible universe, including all the gadgets and gizmos within it. And so right from the start, propmakers and set designers have had the challenge of making things look futuristic using the technology of the present day.

join-hack-chatAll too often, the realities of budgets and time constraints have reduced this crucial world-building to an exercise in blinkenlights. But not always. Ben Eadie is a maker and inventor who works in the world of movie magic, specializing in props and practical effects. While he’s certainly as much in love with blinkenlights as any of us, there’s more than that to making a movie look good. He’ll stop by the Hack Chat to talk about how he incorporates electronics into his practical effect builds, and perhaps even reveal some of the movie magic for us.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, April 20 at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter.

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A flat LiIon battery shown attached inside the gun safe, wired to the original control board

Gun Safe Made Safer With Lithium Battery Upgrade

A proper gun safe should be difficult to open, but critically, allow instant access by the authorized party.[Dr. Gerg] got a SnapSafe and discovered that, while it was quite easy to use, it would also lock the owner out easily whenever the batteries would run out. Meant to be used with four AAA batteries and no way to recharge them externally, this could leave you royally screwed in the exact kind of situation where you need the gun safe to open. This, of course, meant that the AAA batteries had to go.

Having torn a few laptop batteries apart previously, [Dr. Gerg] had a small collection of Li-ion cells on hand – cylindrical and pouch cells alike. Swapping the AAA battery holder for one of these was no problem voltage-wise, and testing showed it working without a hitch! However, replacing one non-chargeable battery with another one wasn’t a viable way forward, so he also added charging using an Adafruit LiPo charger board. One 3D printed OpenSCAD-designed bracket later, he fit the board inside the safe’s frame – and then pulled out a USB cable for charging, turning the battery into a backup option and essentially creating an UPS for this safe. Nowadays, the safe sits constantly plugged into a wall socket, and [Dr. Gerg] estimates it should last for a few weeks even in case of USB power loss.

When you read about hacking gun safes, it’s usually because of their poor security, with even biometric models occasionally falling victim to prying fingers. There’s talk about moving the locking features into the guns themselves, but we remain skeptical. “Powering an electronically locked box with internal batteries” is a fun problem, and just recently, we’ve seen it solved in a different way in this intricate voice-activated lockbox.

Mercury Thrusters: A Worldwide Disaster Averted Just In Time

The field of space vehicle design is obsessed with efficiency by necessity. The cost to do anything in space is astronomical, and also heavily tied to launch weight. Thus, any technology or technique that can bring those figures down is prime for exploitation.

In recent years, mercury thrusters promised to be one such technology. The only catch was the potentially-ruinous environmental cost. Today, we’ll look at the benefits of mercury thrusters, and how they came to be outlawed in short order.

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