A French Minitel terminal becomes a Raspberry Pi-powered mini laptop.

Minitel Terminal Becomes Mini Laptop

In 1980, France took a step into the future when the telecom companies introduced the Minitel system — a precursor to the Web where users could shop, buy train tickets, check stocks, and send and receive electronic mail through a small terminal. Minitel still had 10 million monthly connections in 2009, but the service was discontinued in 2012.

The keyboard of a French Minitel terminal is wired up to an Arduino Pro Micro.So, you can imagine how many Minitel terminals must be floating around at this point. [Gautchh] picked one up at a garage sale a while back and converted it into a battery-powered laptop for taking notes in class. Luckily for us, [Gautchh] recently open-sourced this project and has given us a wiring diagram, STLs, BOM, and a good look into the build process.

[Gautchh] started by gutting the Minitel, but saved the power button and the très chic power indicator that looks like a AA cell. The new 10.4″ LCD screen is held in place with four 3D-printed corner blocks and a bit of hot glue, and the original keyboard (which we’d love to clack on) is now wired up to an Arduino Pro Micro. The main brain — a Raspberry Pi 3B — is easily accessible through a handy little hatch in the back. Well, it looks like we’ve got a new ebay alert to set up.

In the mood for more AZERTY goodness? Check out this gallery of French computers, or a more traditional take on a Minitel with a Raspberry Pi.

Successive approximation register ADC

Homebrew Circuit Explores The Mysteries Of Analog-to-Digital Conversion

When it comes to getting signals from an analog world into our computers, most of us don’t give much thought to how the hardware that does the job works. But as it turns out, there are a number of ways to skin the analog to digital conversion cat, and building your own homebrew successive approximation register ADC is a great way to dispel some of the mystery.

From his description of the project, it’s clear that [Mitsuru Yamada] wasn’t looking to build a practical ADC, but was more interested in what he could learn by rolling his own. A successive approximation register ADC works by quickly cycling through all possible voltage levels in its input range, eventually zeroing in on the voltage of the input signal at that moment and outputting its digital representation. The video below shows how the SAR ADC works visually, using an oscilloscope to show both the input voltage and the output of the internal R-2R DAC. The ADC has an input range of 0 V to 5 V and seven bits of resolution and uses nothing but commonly available 74xx series logic chips and a couple of easily sourced analogs for the sample-hold and comparator section. And as usual with one of his projects, the build quality and workmanship are impeccable.

We love these sorts of projects, which are undertaken simply for the joy of building something and learning how it works. For more of [Yamada-san]’s projects, check out his 6502-based RPN calculator, or the serial terminal that should have been.

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Can We Repurpose Old Wind Turbine Blades?

Wind turbines are a fantastic, cheap, renewable source of energy. However, nothing lasts forever, and over time, the blades of wind turbines fatigue and must be replaced. This then raises the question of what to do with these giant waste blades. Thankfully, a variety of projects are exploring just those possibilities.

A Difficult Recycling Problem

Around 85% of a modern wind turbine is recyclable. The problem is that wind turbine blades currently aren’t. The blades last around 20 to 25 years, and are typically made of fiberglass or carbon fiber. Consisting of high-strength fibers set in a resin matrix, these composite materials are incredibly difficult to recycle, as we’ve discussed previously. Unlike metals or plastics, they can’t just be melted down to be recast as fresh material. Couple this with the fact that wind turbine blades are huge, often spanning up to 300 feet long, and the problem gets harder. They’re difficult and expensive to transport and tough to chop up as well.

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Hackaday Podcast 139: Furter Burner, Glowing Potato Peeler, Hacked Smartwatch, And The Last Atlas

Hackaday editors Tom Nardi and Elliot Williams bring you up to speed on the most interesting stories of the week. Hackaday’s Remoticon and Germany’s Chaos Communication Congress are virtual again this year, but the Vintage Computer Festival will be live. We’ll also talk about ocean-going drones, the recreation of an old-school light bulb with a potato peeler, cheap smart watches with hidden potential, and sanding down shady modules to figure out just how you’ve been scammed. Stick around for some thoughts on turning real-estate signs into a handy prototyping material, and to find out why some very impressive Soviet tech is getting the boot from America’s space program.

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (52.775158 MB)

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Nicolas Bras and his homemade musical instruments

Hacked Set Of Instruments Saves Musician’s Gigs

Most of the horror stories you hear about air travel seem to center around luggage. Airlines do an admirable job of getting people safely to their destinations, but checked baggage is a bit of a crapshoot — it could be there when you land, it could end up taking the scenic route, or it could just plain disappear. That’s bad enough when it contains your clothes, but when it contains your livelihood? Talk about stress!

This was the position musician [Nicolas Bras] found himself in after a recent trip. [Nicolas] was heading for a gig, but thanks to Brussels Airlines, his collection of musical instruments went somewhere else. There was nothing he could do to salvage that evening’s gig, but he needed to think about later engagements. Thankfully, [Nicolas] specializes in DIY musical instruments, made mostly with PVC tubes and salvaged parts from commercial instruments, so the solution to his problem was completely in his hands.

Fair warning to musical instrument aficionados — harvest the neck from a broken ukelele is pretty gruesome stuff. Attached to a piece of pallet wood and equipped with piezo pickups, the neck became part of a bizarre yet fascinating hybrid string instrument. A selection of improvised wind instruments came next, made from PVC pipes and sounding equally amazing; we especially liked the bass chromojara, sort of a flute with a didgeridoo sound to it. The bicycle pump beatbox was genius too, and really showed that music is less about the fanciness of your gear and more about the desire — and talent — to make it with whatever comes to hand.

Here’s hoping that [Nicolas] is eventually reunited with his gear, but hats off to him in the meantime for hacking up replacements. And if he looks familiar, that’s because we’ve seen some of his work before, like his sympathetic nail violin and “Popcorn” played on PVC pipes.

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This Week In Security: Apache Nightmare, REvil Arrests? And The Ultimate RickRoll

The Apache HTTP Server version 2.4.49 has a blistering vulnerability, and it’s already being leveraged in attacks. CVE-2021-41773 is a simple path traversal flaw, where the %2e encoding is used to bypass filtering. Thankfully the bug was introduced in 2.4.49, the latest release, and a hotfix has already been released, 2.4.50.

curl --data "echo;id" 'http://127.0.0.1:80/cgi-bin/.%2e/.%2e/.%2e/.%2e/bin/sh'

If that returns anything other than a 403 error, your server may be vulnerable. It’s worth pointing out that Apache is shipped with a configuration block that mitigates this vulnerability.

# Deny access to the entirety of your server's filesystem. You must
# explicitly permit access to web content directories in other
# blocks below.
#
<Directory />
AllowOverride none
Require all denied
</Directory>

The Day The Internet Stood Still

You might have noticed a bit of a kerfluffel on the Internet on Monday. Facebook dropped out for nearly six hours. While the break was nice for some, it was a major problem for others. What exactly happened? The most apparent cause was that the Facebook.com domain was returning nxdomain to DNS lookups. This led to some fun tweets, with screen caps showing Facebook.com for sale.
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Quint explaining his water turbine

Power Your Home With A Water Battery

I’ve stated it before on Hackaday but one of the most interesting engineering challenges posed to me this year was “how could you store enough energy to power a decent portion of a home for several hours without using batteries, all while staying within the size of a typical suburban plot?” [Quint Builds] attempts something up that alley by using solar power to pump water up onto his roof and later releasing it for power generation. (Video, embedded below.)

Earlier [Quint] had built a water collecting system using his gutters and a bell siphon but wasn’t satisfied with the overall power output. Using the turbine he had created for that system, he put a 55-gallon drum on top of his roof with the help of some supporting structures. We’d like to advise the public to consult a professional before adding a large heavy weight on top of your roof, but [Quint] forges ahead after studying his trusses and determining it to be a risk he is willing to take. A solar panel runs a small pump that pumps water from a reservoir up to the top of the roof when the sun shines with a float switch in the roof barrel stopping the motor once it’s full. A valve at the bottom allows water to spin the turbine and fill back into the bottom reservoir, forming a closed loop. There were a few snags along the way with prototype circuits not being fully contacted and the motor needing water cooling, an issue fixed by a custom CNC’d heat sink. The fixes for the various issues are almost as entertaining to see as the actual system itself.

It’s incredible to see lights come on powered by water alone but also sobering to realize just how much water you’d need to power a typical home. Perhaps if [Quint] upgrades, he can swap out the small motor for a larger 3D printed water pump.

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