Year: 2020

Overclocking And Watercooling The TI-84, Just Cause

June 16, 2020 by 23 Comments

The TI-84 is an enduring classic – the calculator that took many through high school, college and beyond. A hacker’s favorite, it’s been pushed to the limits in all sorts of ways. The crew at [Linus Tech Tips] decided to join in the fun, overclocking a TI-84 Plus and adding water cooling to boot. 

The TI-84 uses a simple resistor capacitor circuit to generate its clock, making it overclocking it a cinch. By changing the resistor value in the circuit, the clock can be made to run faster. The team have some issues with pads delaminating from the PCB, but manage to sub in a trimpot which lets the clock be changed on the fly. A boost of 10MHz over stock gets the calculator operating at 26MHz, with notably quicker performance in the TI port of Doom 2. Without accurate measurement of CPU temps, it’s hard to say whether watercooling the calculator is justified. However, the team do a great job of entirely overengineering the solution, with a custom-made cooling block hooked up to a massive spherical reservoir.

With the stability issues inherent in overclocking, and the unwieldy watercooling tubes, it’s not a good hack in the practicality sense. It is, however, quite amusing, and that’s always worth something. TI calculators have long been targets for hackers, and you can even get them online if you so desire. Video after the break.

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Hackaday Prize: Cal-Earth Is Digging Deep To Shelter Those In Need

June 16, 2020 by 41 Comments

For the average person, a government order to shelter in place or stay at home comes with some adjustments. Many changes are cerebral: we navigate vast expanses of togetherness with our families while figuring out how to balance work, life, and newfound teaching roles. Other changes are physical, like giving each other enough space to be successful. A lucky few can say that not much has changed for them personally. No matter what your position is in this thing, if you have a place to shelter, you’re doing better than 20% of the world’s population.

CalEarth founder Nader Khalili leads from the top of a dome in progress.

An estimated 1.6 billion people, including those who are homeless and those who are refugees, are living without adequate shelter. The need for shelter is a cornerstone of human well-being, and yet building a home for oneself can seem totally out of reach. After all, most people aren’t qualified to build a habitable structure without an architect, an engineer or two, and a team of construction workers with heavy equipment. Or are they?

It all depends on the design and materials. Dome structures have been around for centuries, and the idea of using packed earth to build walls is a tried and true concept. Architect Nader Khalili perfected a blend of the two concepts with his SuperAdobe construction system, which employs long sandbags filled with moistened earth. Khalili opened the California Institute of Earth Architecture (CalEarth) in 1991 to explore the possibilities of SuperAdobe and to educate others in the building process.

I grew up among the poor. I am one of nine children, and constantly knew need. I never forgot, so now I’m responding.    — Nader Khalili

This year, the Hackaday Prize is teaming up with CalEarth to push their widely accessible concept of sustainable living into the future. As with our other three non-profits, this effort is twofold. The open call challenge invites you to design sustainable add-ons for SuperAdobe homes that expand their livability and are simple to build and use. Throughout June and July, our CalEarth Dream Team members are working to find ways to automate the process so that these homes can be built much faster, and in turn help more people.

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Lonnie Johnson, Prolific Engineer And Hero To Millions Of Kids (Even If They Don’t Know It)

June 16, 2020 by 29 Comments
The current generation Super Soaker XP30. (Hasbro)
The current generation Super Soaker XP30. (Hasbro)

To be a child in the 1970s and 1980s was to be of the first generations to benefit from electronic technologies in your toys. As those lucky kids battled blocky 8-bit digital foes, the adults used to fret that it would rot their brains. Kids didn’t play outside nearly as much as generations past, because modern toys were seducing them to the small screen. Truth be told, when you could battle aliens with a virtual weapon that was in your imagination HUGE, how do you compete with that.

How those ’80s kids must have envied their younger siblings then when in 1990 one of the best toys ever was launched, a stored-pressure water gun which we know as the Super Soaker. Made of plastic, and not requiring batteries, it far outperformed all squirt guns that had come before it, rapidly becoming the hit toy of every sweltering summer day. The Super Soaker line of water pistols and guns redefined how much fun kids could have while getting each other drenched. No longer were the best water pistols the electric models which cost a fortune in batteries that your parents would surely refuse to replace — these did it better.

You likely know all about the Super Soaker, but you might not know it was invented by an aerospace engineer named Lonnie Johnson whose career included working on stealth technology and numerous projects with NASA.

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A Properly Engineered UV Chamber For PPE Sanitization

June 16, 2020 by 49 Comments

Designed to be used once and then disposed of, personal protective equipment (PPE) such as N95 face masks proved to be in such short supply during the early days of the COVID-19 pandemic that getting a few extra uses out of them by sanitizing them after a shift seemed smart. And so we saw a bunch of designs for sanitizing chambers, mostly based on UV-C light and mostly, sad to say, somewhat dodgy looking. This UV-C disinfection chamber, though, looks like a much better bet.

The link above is to the final installment of a nine-part series by [Jim] from Grass Roots Engineering. The final article has links to all the earlier posts, which go back [Jim]’s early research on UV-C sanitization methods back in March. This led him to settle on an aquarium sanitizer as his UV-C source. A second-hand ultraviolet meter allowed him to quantify the lamp’s output and plan how best to use it, which he did using virtual models of various styles of masks.  Knowing that getting light on every surface of the mask is important, he designed a mechanism to move the mask around inside a reflective chamber. The finished chamber, which can be seen in the video below, is 3D-printed and looks like it means business, with an interlock for safety and a Trinket for control.

We love the level of detail [Jim] put into these posts and the thoughtful engineering approach he took toward this project. And we appreciate his careful testing, too — after all, it wouldn’t do to use a germicidal lamp that actually doesn’t emit UV-C.

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Why You (Probably) Won’t Be Building A Replica Amiga Anytime Soon

June 16, 2020 by 68 Comments

Early in 2019, it  became apparent that the retro-industrial complex had reached new highs of innovation and productivity. It was now possible to create entirely new Commdore 64s from scratch, thanks to the combined efforts of a series of disparate projects. It seems as if the best selling computer of all time may indeed live forever.

Naturally, this raises questions as to the C64’s proud successor, the Amiga. Due to a variety of reasons, it’s less likely we’ll see scratch-build Amiga 500s popping out of the woodwork anytime soon. Let’s look at what it would take, and maybe, just maybe, in a few years you’ll be firing up Lotus II (or, ideally, Jaguar XJ220: The Game) on your brand new rig running Workbench 1.3. Continue reading “Why You (Probably) Won’t Be Building A Replica Amiga Anytime Soon” →

Tackling Trunked Radio With Software

June 16, 2020 by 12 Comments

For those starting to wade into radio as a hobby, one of the first real technical challenges is understanding trunked radio systems. On the surface, it seems straightforward: A control channel allows users to share a section of bandwidth rather than take up one complete channel, allowing for greater usage of the frequency range. In practice though it can be difficult to follow along, but now it’s slightly easier thanks to software defined radio.

This guide comes to us from [AndrewNohawk], who is located in San Francisco and is using his system to monitor police, fire, and EMS activity. These groups typically used trunked radio systems due to the large number of users. For listening in, nothing more than an RTL-SDR setup is needed, and the guide walks us through using this setup to find the control channels, the center frequency, and then identifying the “talk groups” for whichever organization you want to listen in on.

The guide goes into great detail, including lists of software needed to get a system like this started up, and since [AndrewNohawk] is a self-identified “radio noob” the guide is perfectly accessible to people who are new to radio and specifically new to trunked systems like these. Once you get the hang of it, it’s not too hard to scale up, either.

Retrotechtacular: The Nernst Lamp

June 16, 2020 by 56 Comments

After dominating the illumination market for more than a century, it’s easy to think of the glowing filament of the standard incandescent lamp as the only way people found to turn electricity into light. But plenty of fertile minds turned out alternative designs, one of which is the fascinating Nernst lamp, which we’d previously never heard of.

If the name sounds familiar, it’s likely through exposure to [Walther Nernst]’s equation for electrochemistry, or for his “New Heat Theorem” which eventually became the Third Law of Thermodynamics. Pal of [Einstein] and eventual Nobel laureate, [Nernst] was also a bit of a tinkerer, and he came up with a design for an incandescent lamp in 1897 that was twice as efficient as carbon-filament lamps. The video below, from the Edison Tech Center, details the design, which used a ceramic “glower rod” that would incandesce when current flowed through it. The glower, though, was not conductive until it was quite hot, so separate heater coils that gave the glower a start on the process were included; these were switched off by a relay built into the base of the lamp once the glower started conducting.

It’s a complicated design, but its efficiency, coupled with a better light spectrum and the fact that it didn’t need a vacuum bulb since the glower wouldn’t oxidize like a carbon or tungsten filament, gave it certain advantages that let it stake out a decent share of the early market for electric illumination. It was even the light source for one of the first facsimile machines. We find it a very clever use of what were at the time exotic materials, and wonder if this could have lead to something like vacuum tubes without the vacuum.

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