This Vintage Phone Goes Cellular

Way back in the good old days, life ran at a slower pace. It took us almost a decade to get to the moon, and dialling the phone was a lazy affair which required the user to wait for the rotary mechanism to rewind after selecting each digit. Eager to bring a taste of retro telephony into the modern era, [Marek] retrofitted this vintage Polish telephone with a GSM upgrade.

The phone [Marek] salvaged had already been largely gutted, so there was little to lose in the transformation. A Motorola D15 GSM module was sourced from an alarm system to provide a network connection to the project. An Atmega328 was then used to translate the rotary dial mechanics into something more usable by the cellular module.

Attention to detail can really make a project shine, and [Marek] didn’t skimp in this area. The original ringer was rewound to operate with a half H-bridge at a lower voltage more suitable to the modern electronics inside. The microcontroller also helped out by using its PWM hardware to simulate a dialtone and the characteristic sound of pulse dialling.

It’s always nice to see retro hardware given a new lease on life. Unfortunately, GSM networks aren’t long for this world, so a further update may be required before long. These old phones have plenty of potential, as we’ve seen before.

The Design And Construction Of A Tribute To A Bomber Pilot

Decades ago, [wilmracer]’s grandfather was piloting a B-17 over the Rhine, and as it goes, aviation runs in families. Now, more than 70 years later [wilmracer] is deep, deep into remote controlled aircraft, and he’s building an exacting scale model of the B-17G his grandfather flew on his last bombing mission over Europe.

This is a scratch build, with the design taken directly from the plans and schematics of a B-17. [wilmracer] has already paid the money to go up in the preserved B-17 Aluminum Overcast to get a better idea of the layout, and now he’s deep into cutting foam and bending balsa sheets. The first part of the build was arguably the hardest, and the main landing gear was expertly constructed out of aluminum tube and linear servos. The horizontal stab follows traditional building techniques of foam and carefully sanded balsa sheets. The fuselage is impressive, with the formers built out of foam, and eventually covered in 1/16″ balsa and wrapped in fiberglass.

If you’re going to do a large-scale model airplane, that also means you’ve got to do detailing. That means steam gauges rendered in 3D printed parts. [wilmracer] is modeling the cockpit and the machine guns in 1:9 scale. This is going to be an awesome build, and yes, there will eventually be plans.

Of course, this isn’t the biggest small B-17 ever built. That record goes to the 1:3 scale Bally Bomber, a real, not remote controlled plane built over the course of two decades by [ Jack Bally]. This is a real plane with a 34 foot wingspan that weighs 1800 pounds. Yes, it flies, and it went to Oshkosh last summer. Remote control really is the way to go with something like this, though: you can appease the rivet counters, put more power on the props, and you don’t need to worry too much about pesky things like regulations and laws. We’re looking forward to see where this project goes, and to the sound of a great PLA overcast thundering over the treetops.

A Lemon Battery Via 3D Printing

There are a whole bunch of high school science experiments out there that are useful for teaching students the basics of biology, physics, and chemistry. One of the classics is the lemon battery. [iqless] decided to have a play with the idea, and whipped up a little something for his students.

The basic lemon battery is remarkably simple. Lemon juice provides the electrolyte, while copper and and zinc act as electrodes. This battery won’t have a hope of charging your Tesla, but you might get enough juice to light an LED or small bulb (pun intended).

[iqless] considered jamming electrodes directly into lemons to be rather unsophisticated. Instead, an electrolyte tray was 3D printed. The tray can be filled with lemon juice (either hand-squeezed or straight from a bottle) and the tray has fixtures to hold copper pennies and zinc-plated machine screws to act as the electrodes. The tray allows several cells to be constructed and connected in series or parallel, giving yet further teaching opportunities.

It’s a fun twist on a classroom staple, and we think there are great possibilities here for further experimentation with alternative electrolytes and electrode materials. We’d also love to see a grown-up version with a large cascade of cells in series for lemon-based high voltage experiments, but that might be too much to ask. There’s great scope for using modern maker techniques in classroom science – we’ve discussed variations on the egg drop before. Video after the break.

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Cheap Power Over Ethernet For The ESP32

While most projects we see with the ESP32 make use of its considerable wireless capabilities, the chip can be connected to the wired network easily enough should you have the desire to do so. [Steve] liked the idea of putting his ESP32s on the wired network, but found the need for a secondary power connection burdensome. So he took it upon himself to modify some cheap Power Over Ethernet (PoE) hardware and create a single-cable solution (Google Translate).

[Steve] bought a PoE module intended for security cameras and ran a close eye over the board to figure out what kind of hardware it was using to generate the nominal 12 V output. He identified an MP2494 step-down converter, and with the datasheet in hand found how the output voltage is configured by changing the values of resistors in the circuit. Swapping out the stock 21.5 kΩ resistor for a 57.1 kΩ one changed the output of the converter to the 5 V necessary for his electronics.

But of course that was only half of the problem solved; he still had to connect the Ethernet side of the PoE device to the Waveshare LAN8720 board that’s providing Ethernet for the ESP32. So he removed the RJ45 jack from the LAN8720 completely, and wired that directly to the connector on the PoE board. Helpfully, the PoE board had all the pins labeled on the bottom side so this wasn’t nearly as tricky to figure out as you might expect (if only it was always that easy).

We’ve previously covered the Waveshare LAN8720 board for anyone who’s interested in the ins and outs of getting their ESP32 talking Ethernet. If you’re wondering how you can put PoE to work for you, our very own [Jonathan Bennett] has been showing off his home Raspberry Pi infrastructure which makes extensive use of the new PoE hat.

Modernizing a Soviet-era LED Matrix

Used in everything from calculators to military hardware, the 3LS363A is an interesting piece of vintage hardware. With a resolution of 5 x 7 (plus a decimal point), the Soviet-made displays contain no electronics and are simply an array of 36 green LEDs. It’s not hard to drive one of them in a pinch, but [Dmitry Grinberg] thought this classic device deserved a bit better than the minimum.

He’s developed a small board that sits behind the 3LS363A and allows you to control it over I2C for a much more modern experience when working with these vintage displays. Powered by the ATtiny406, his adapter board makes it easy to chain the modules together and even handles niceties like flipping the displayed image to account for different mounting positions. While most of us probably won’t have the chance to play around with these relatively rare displays, there’s still plenty of useful information here if you’re thinking of creating your own I2C gadgets.

In his write-up, [Dmitry] explains his rationale behind the design and some of the quirks of working with the display. For example he explains how he gave each column of the display its own FET, but to save space on the board ended up running the single decimal point (technically its own column) directly off of a spare GPIO pin. Relying on the low duty cycle, he even left current limiting resistors off the design. The end result is a tiny board that keeps the same footprint of the 3LS363A itself.

[Dmitry] went all out with developing the firmware for his new “smart” 3LS363A displays, and has written up documentation for the different commands he has implemented. From re-configuring the I2C address to updating the firmware, he’s made sure no stone was left unturned for this project. We’re not ones to shy away from a quick and dirty code, but it’s always nice to see when somebody has really put some thought into the software side of a project.

We’ve seen our fair share of oddball Soviet displays here at Hackaday, utilizing everything from heavy duty incandescent bulbs to remarkably tiny “intelligent” LEDs. While it’s unlikely any of them will dethrone the nixie as king of the retro display devices, it’s always interesting to see unusual hardware being used in the wild.

Operation Backfire: Witness to the Rocket Age

As the prospects for Germany during the Second World War began to look increasingly grim, the Nazi war machine largely pinned their hopes on a number of high-tech “superweapons” they had in development. Ranging from upgraded versions of their already devastatingly effective U-Boats to tanks large enough to rival small ships, the projects ran the gamut from practical to fanciful. After the fall of Berlin there was a mad scramble by the Allied forces to get into what was left of Germany’s secretive development facilities, with each country hoping to recover as much of this revolutionary technology for themselves as possible.

V-2 launch during Operation Backfire

One of the most coveted prizes was the Aggregat 4 (A4) rocket. Better known to the Allies as the V-2, it was the world’s first liquid fueled guided ballistic missile and the first man-made object to reach space. Most of this technology, and a large number of the engineers who designed it, ended up in the hands of the United States as part of Operation Paperclip. This influx of practical rocketry experience helped kick start the US space program, and its influence could be seen all the way up to the Apollo program. The Soviet Union also captured V-2 hardware and production facilities, which subsequently influenced the design of their early rocket designs as well. In many ways, the V-2 rocket was the spark that started the Space Race between the two countries.

With the United States and Soviet Union taking the majority of V-2 hardware and personnel, little was left for the British. Accordingly their program, known as Operation Backfire, ended up being much smaller in scope. Rather than trying to bring V-2 hardware back to Britain, they decided to learn as much as they could about it in Germany from the men who used it in combat. This study of the rocket and the soldiers who operated it remains the most detailed account of how the weapon functioned, and provides a fascinating look at the incredible effort Germany was willing to expend for just one of their “superweapons”.

In addition to a five volume written report on the V-2 rocket, the British Army Kinematograph Service produced “The German A.4 Rocket”, a 40 minute film which shows how a V-2 was assembled, transported, and ultimately launched. Though they are operating under the direction of the British government, the German soldiers appear in the film wearing their own uniforms, which gives the documentary a surreal feeling. It could easily be mistaken for actual wartime footage, but these rockets weren’t aimed at London. They were being fired to serve as a historical record of the birth of modern rocketry.

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Hardware Developers Didactic Galactic Call for Talks

Hackaday is known for having the best community around, and we prove this all the time. Every month, we hold meetups across the United States. This, in addition to conferences and mini-cons across the globe mean Hackaday is the premiere venue for technical talks on a wide variety of hardware creation. Everything from Design for Manufacturing, to the implementation of blinky bling is an open topic.

Now, we’re looking for the talk you can give. The Hardware Developers Didactic Galactic is a monthly gathering hosted by Supplyframe, the Overlords of Hackaday. It’s filled with the technical elite of San Francisco, usually held on the last Thursday of the month. We’re looking for a talk you can give, whether it’s about your IoT irrigation system, or that time you created something out of transistors and capacitors.  We’re looking for speakers for all of 2019, and if you have a tale of the trials and tribulations of injection molding or Bluetooth pairing, we want to hear from you.

We have a sign-up form for presenters, and if you have something to present to a group of fantastic, technical people, we want to hear from you. All these talks are streamed and recorded, so if you’d like an idea of what we’re going for, just check out some of the previous talks. We have talks on how to start a decentralized space agency, wearable technology and fashion, optics and FPGAs, and System-in-Package tech. We’ve got a speaker travel stipend of up to $300, so there’s no excuse for you not to present your latest work.

There are thousands of people in the Hackaday community that have tons to contribute, and this is your chance. You are the best of the best, and we want to hear what you have to teach the rest of the community.