It’s Bad Apple, But On A 32K EPROM

February 19, 2022 by Jenny List 12 Comments

The Bad Apple!! video with its silhouette animation style has long been a staple graphics demo for low-end hardware, a more stylish alternative to the question “Will it run DOOM?”. It’s normal for it to be rendered onto a screen by a small microcomputer or similar but as [Ian Ward] demonstrates in an unusual project, it’s possible to display the video without any processor being involved. Instead he’s used a clever arrangement involving a 32K byte EPROM driving a HD44780-compatible parallel alphanumeric LCD display.

While 32K bytes would have seemed enormous back in the days of 8-bit computing, even when driving only a small section of an alphanumeric LCD it’s still something of a struggle to express the required graphics characters. This feat is achieved by the use of a second EPROM, which carries a look-up table.

It’s fair to say that the result which can be seen in the video below the break isn’t the most accomplished rendition of Bad Apple!! that we’ve seen, but given the rudimentary hardware upon which it’s playing we think that shouldn’t matter. Why didn’t we think of doing this in 1988!

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Against The Cloud

February 19, 2022 by Elliot Williams 58 Comments

One of our writers is working on an article about hosting your own (project) website on your own iron, instead of doing it the modern, cloudy-servicey way. Already, this has caused quite a bit of hubbub in the Hackaday Headquarters. Who would run their own server in 2022, and why?

The arguments against DIY are all strong. If you just want to spin up a static website, you can do it for free in a bazillion different places. GitHub’s Pages is super convenient, and your content is version controlled as a side benefit. If you want an IoT-type data-logging and presentation service, there are tons of those as well — I don’t have a favorite. If you want e-mail, well, I don’t have to tell you that a large American search monopoly offers free accounts, for the low price of slurping up all of your behavioral data. Whatever your need, chances are very good that there’s a service for you out there somewhere in the cloud.

And that’s awesome if you only want the service provided. But what if you want to play around? Or learn how it all works under the hood? This is Hackaday!

For instance, you could run your own mail server just for your friends and family. The aforementioned search monopolist will probably flag all of your e-mail as spam, partly because they don’t trust small e-mail providers, and partly because that’s the “m” in monopoly. But if you can get folks to whitelist the addresses, you’ll be in business. And then you open up a world of fun and foolery. You can write hooks to automatically handle mail, or you can create an infinite number of mail accounts, even on the fly as per Spamgourmet, the most awesome anti-spam tool of the last 30 years. Or you can invent your own. Run a mailing list for your relatives. Or do something stupid.

I used to run a service where, when a particular account received an e-mail, the attached photo was pushed up to a website with the subject line as the caption. Instant photo-blog, of the strangest and least secure sort. Getting it running was a few lines of Bash scripting, and an afternoon of fun. Is there a service that does this, already existing in the cloud? Probably. One that allows you a little privacy and doesn’t track your every move? Maybe. But even if there is, would I have learned about sendmail by using this service? Nope!

I hear you saying “security” under your breath, and you’re right. This system was secured by lock made of purest obscurity. But still, in seven years of running the service, nobody guessed the magic e-mail address, not once. Knowledge of the e-mail address was essentially a password, but if I needed extra security I probably could have implemented it in a few lines of Bash anyway. The webpage itself was static HTML, so good luck with that, Hackerman! (The site’s been down for a while now, so you missed your chance.)

If you just want a service, you can be served. But if you want to be a server, a first-class Internet citizen, with your own cloud in the sky, nothing’s stopping you either. And in contrast to using someone else’s computers, running your own is an invitation to play. It’s a big, Internet-connected sandbox. There are an infinity of funny ideas out there that you can implement on your own box, and a lot to learn. If you hack on someone else’s box, it’s a crime. If you hack on your own, it’s a pleasure.

I know it’s anachronistic, but give it a try. (PDF, obscenity, uncorrected typos.) Be your own cloud.

Mon Dieu! French Parent Kills Cell Service For An Entire Town To Stop Kids Surfing

February 19, 2022 by Jenny List 34 Comments

It used to be that having technical skills meant that fixing the computer problems of elderly relatives was a regular occurrence. Over the last few years this has been joined by another request on our time; friends with teenage children requesting help configuring their routers such that Internet access is curtailed when the kids should sleeping. In France a desperate parent took more extreme measures, buying a wideband frequency jammer to ensure les petits anges can’t waste the night away on social media sites through their cellular connections. It had the intended effect, but sadly it also interrupted cellular coverage over a wide area The French spectrum regulator ANFR sent in their investigators (French, Google Translate link), and now the unfortunate parent faces the prospect of up to 6 months imprisonment and €30,000 fine for owning and using a device that’s illegal in France.

A cursory search of everybody’s favourite online electronics bazaars will find plenty of these devices, so perhaps what’s surprising is that we don’t see more of these devices even if it’s not the first tale of interference tracking that we’ve seen. Judging by the strategies our friends with kids take, we’d suggest meanwhile to the unfortunate French person, that they simply equip their kids with restricted data plans.

Mirror, Mirror On The Wall, Do My Eyes Deceive Me After All

February 19, 2022 by Matthew Carlson 4 Comments

Say what you will about illusions, [Create Inc] has some 3D prints that appear to change shape when viewed in a mirror. For example, circles transform into stars and vice versa. A similar trick was performed by [Kokichi Sugihara] in 2016, where he showed circles that appear as squares in the mirror. For the trick to work, the camera’s position (or your eye) is important as the shapes look different from different angles. The illusion comes in when your brain ignores any extra information and concludes that a much more complex shape is a simpler one. [Create Inc] walks you through the process of how the illusion works and how it was created in Blender.

When he posted the video on Reddit, most seemed to think that it wasn’t a mirror and there was some camera trickery. At its heart, this is reverse-engineering a magic trick, and we think it’s an impressive one. STL files are on Thingiverse or Etsy if you want to print your own. We covered a second illusion that [Kokichi] did that relies on a similar trick.

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Homemade Toy Wind Tunnel Blows (Really Well)

February 18, 2022 by Adam Zeloof 6 Comments

Sometimes a kid wakes up on Christmas morning and runs downstairs, only hoping to see one thing: a shiny new wind tunnel. This past December, that’s exactly what [SparksAndCode]’s son found ~~under~~ beside the tree, complete with a bag of scarves, ping-pong balls, and other fun things to launch through it (in the name of physics, of course).

The real story here starts about a week before Christmas, when [SparksAndCode]’s son was enthralled by a similar device at a science museum. At his wife’s suggestion, [SparksAndCode] got to work designing a and building a wind tunnel with hardware-store parts, his deadline looming ahead. The basic structure of the tunnel is three rods which support plywood collars. The walls are formed by plastic sheets rolled inside the collars to make a tube. Underneath, a Harbor Freight fan supplies a nice, steady stream of air for endless entertainment.

After finding a few bugs during his son’s initial beta testing on Christmas morning, [SparksAndCode] brought the wind tunnel back into the shop for a few tweaks and upgrades, including a mesh cover on the air intake to stop things from getting sucked into the fan. The final result was a very functional (and fun!) column of air. Looking for even more function (but not necessarily less fun)? We’ve got you covered too with this home-built research wind tunnel from a few years back.

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Open Source LXI Tools Free Us From Vendor Bloat

February 18, 2022 by Dave Rowntree 8 Comments

LXI, or LAN eXtensions for Instrumentation is a modern control standard for connecting electronics instrumentation which supports ethernet. It replaces the older GPIB standard, giving much better performance and lower cost of implementation. This is a good thing. [Martin Lund] has created the open source lxi-tools project which enables us to detach ourselves from the often bloated vendor tools usually required for talking LXI to your bench equipment. This is a partial rewrite of an earlier version of the tool, and now sports some rather nice features such as mDNS for instrument discovery, support for screen grabbing, and a LUA-based scripting backend. (API Link)

SCPI or Standard Commands for Programmable Instruments is the text-based language spoken by many instruments, allowing control and querying of an instrument. Just to be clear, SCPI is not at all a new thing, and older instruments that have GPIB or RS232 connectors, still could talk SCPI. lxi-tools is not for those. Some instruments can also be very picky about the formatting of commands, especially if they’re buggy, so the ability to interactively debug commands is very desirable. It is quite possible to make poor use of SCPI commands in your test script and end up with tests that just take far longer to execute that they need to. lxi-tools has a benchmarking tool too, which helps you to dig in and find out where all the time is going and make suitable adjustments.

We’ve not seen much about LXI on Hackaday, but we did cover using PyVISA for dealing with SCPI-over-GPIB in python. If you have an older instrument with GPIB and you don’t want to sell a internal organ to pay for a USB adaptor, here’s one you can make yourself.

RC Snowmobile Makes Tracks On Ice

February 18, 2022 by Bryan Cockfield 7 Comments

With all the futuristic technology currently at our disposal, it seems a little bizarre that most passenger vehicles are essentially the same thing that they were a century ago. Four wheels, a motor, and some seats would appear to be a difficult formula to beat. But in the 3D printing world where rapid prototyping is the name of the game, some unique vehicle designs have been pushed out especially in the RC world. One of the latest comes to us from [RCLifeOn] in the form of a single-wheeled RC snowmobile.

While not a traditional snowmobile with tracks, this one does share some similarities. It has one drive wheel in the back printed with TPR for flexibility and it also includes studs all along its entire circumference to give it better traction on ice. There are runners in the front made from old ice skates which the vehicle uses for steering, and it’s all tied together with an RC controller and some lithium batteries to handle steering and driving the electric motor.

There were some design flaws in the first iteration of this vehicle, including a very large turning radius, a gearing setup with an unnecessarily high torque, and a frame that was too flexible for the chain drive. [RCLifeOn] was also testing this on a lake which looked like it was just about to revert to a liquid state which made for some interesting video segments of him retrieving the stuck vehicle with a tree branch and string. All in all, we are hopeful for a second revision in the future when some of these issues are hammered out and this one-of-a-kind vehicle can really rip across the frozen wastes not unlike this other interesting snowmobile from a decade ago.

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