Vintage Telegraph Sounder Clicks Again

It’s sad, when you think about it: a retired railroad telegraph operator, who probably once pounded out code at 40 words per minute, with a collection of vintage sounders silently gathering dust on a shelf. [kthrace] decided to do something about that, and built this Morse sender to bring those old sounders back to life.

As archaic as Morse might seem, it’s a life skill, one the 92-year old former brass-pounder for whom this was built was eager to practice again. There are code practice oscillators, of course, but dits and dahs are no substitutes for the electromagnetic clicks and clacks that once filled this old fellow’s days. There’s not much information on the circuit, but it looks like [kthrace] chose a RedBoard to read Morse from an SD card and drive some relays to support up to four sounders; that’ll make a racket! The case is custom made and nicely complements the wood and brass of the J.H. Bunnell and Co. sounder, which still sounds great after all these years.

Test your Morse skills in the video below – copying code is a lot harder from a sounder than from an oscillator. Find yourself in need of practice? We’ve got you covered.

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That Sucks! Death of a Tesla Coil

[Electroboom] always has some entertaining videos. He recently tried to run his Tesla coil in a vacuum. The video shows some interesting results, along with his usual bleeped out expletives as he drills into his hand and suffers other indignities in the name of electronics.

Unfortunately, a bit of extra bolt caused the coil to arc internally, eventually leading to the impressive device shuffling off its mortal… um, well, let’s just say its untimely demise. Along the way, though, you get to see some interesting techniques for building a silicone seal for the vacuum chamber, and some neat Tesla coil tricks with a closed off syringe.

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Two-Piece Boxes Thanks to Laser-Cut Flex Hinges

It sounds like a challenge from a [Martin Gardner] math puzzle from the Scientific American of days gone by: is it possible to build a three-dimensional wooden box with only two surfaces? It turns out it is, if you bend the rules and bend the wood to make living hinge boxes with a laser cutter.

[Martin Raynsford] clearly wasn’t setting out to probe the limits of topology with these boxes, but they’re a pretty neat trick nonetheless. The key to these boxes is the narrow to non-existent kerf left by a laser cutter that makes interference fits with wood a reality. [Martin]’s design leverages the slot and tab connection we’re used to seeing in laser-cut boxes, but adds a living flex-hinge to curve each piece of plywood into a U-shape. The two pieces are then nested together like those old aluminum hobby enclosures from Radio Shack. His GitHub has OpenSCAD scripts to parametrically create two different styles of two-piece boxes so you can scale it up or (somewhat) down according to your needs. There’s also a more traditional three-piece box, and any of them might be a great choice for a control panel or small Arduino enclosure. And as a bonus, the flex-hinge provides ventilation.

Need slots and tabs for boxes but you’re more familiar with FreeCAD? These parametric scripts will get you started, and we’ll bet you can port the flex-hinge bit easily, too.

Remotely Get Root On Most Smart TVs With Radio Signals

[Rafael Scheel] a security consultant has found that hacking smart TVs takes nothing much more than an inexpensive DVB-T transmitter, The transmitter has to be in range of the target TV and some malicious signals. The hack works by exploiting hybrid broadcast broadband TV signals and widely known about bugs in web browsers commonly run on smart TVs, which seem run in the background almost all the time.

Scheel was commissioned by Cyber security company Oneconsult, to create the exploit which once deployed, gave full root privileges enabling the attacker to setup and SSH into the TV taking complete control of the device from anywhere in the world. Once exploited the rogue code is even unaffected by device reboots and factory resets.

Once a hacker has control over the TV of an end user, he can harm the user in a variety of ways, Among many others, the TV could be used to attack further devices in the home network or to spy on the user with the TV’s camera and microphone. – Rafael Scheel

Smart TV’s seem to be suffering from  IoT security problems. Turning your TV into an all-seeing, all-hearing surveillance device reporting back to it’s master is straight out of 1984.

A video of a talk about the exploit along with all the details is embedded below.
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Hackaday Prize Entry: Pocket Serial Terminal

When you have a microcontroller or other microcomputer on the bench in front of you and it lacks the familiar keyboard and display of a modern desktop computer, what do you do when you wish to program it or otherwise issue commands? Unless you are a retro computer enthusiast who longs for a set of Altair-style toggle switches, the chances are you’ll find its serial port and attach a terminal.

Serial terminals, devices containing a screen and keyboard hooked up to send and display text from a serial port, used to be a staple of computing, but as standalone devices, they’re now rather rare. In most cases nowadays using a serial terminal will mean opening up a terminal emulator in your modern OS, Linux, Windows, or MacOS, but there is still a use for standalone hardware. [Kuldeep Singh Dhaka] certainly thinks so, because he’s making an extremely nice portable terminal with an LCD screen.

The terminal emulates a venerable DEC VT-100 terminal, but since it’s built around an STM32F105 ARM microcontroller we’re sure it could emulate other models with appropriate software. It takes either a USB or a PS/2 keyboard, so we’d expect to see it paired with a suitably tiny portable keyboard when it in use. There is no source code available for it yet since this is very much still a project in development that we’re featuring now because it is a 2017 Hackaday Prize entry, but he assures us that code will be on its way and it will be GPL licenced.

He’s even posted a video that we’ve placed below the break of the device in operation, connected to a machine running MicroPython. We’d probably turn off that beep, though.

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The Best Of VCF East

Last weekend was the Vintage Computer Festival East in Wall, New Jersey. While this yearly gathering of nerds nerding out on old computers might be a bit too obscure for some, there are always amazing exhibits of actual historical importance. A few Enigma machines showed up, and the rarest Commodore goodies made an appearance. We saw the pre-history of Hackaday and ‘maker’ culture with Southwest Technical Products Corporation, and found out it was probably, possible to build a RepRap in the 80s. You can’t know where you’re going unless you know where you came from, and even though the old timers were a bit more grizzled than us the Vintage Computer Festival shows how little things have actually changed.

What was the coolest and weirdest stuff at VCF? What does the Silverball pinball museum look like? Check that out below.

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Hacking a Vintage TV into an Oscilloscope

Do you still have an old analog CRT  television lying around? With the advent of digital signals, analog TV´s are going to the dumpster or the recycling center. But you can still put them to good use, just as [GreatScott!] did, by converting the TV into a crude oscilloscope.

The trick is to take control of the two deflection coils that move the electron beam inside the CRT in the horizontal and vertical directions. The video describes in detail the process of identifying the coils and using an Arduino nano in combination with a DAC to amplify the input signal in order to get the waveform in the TV screen. Step by step explanations and great editing make this project delightful to watch.

Even if you do not follow [GreatScott!]´s steps to build a simple oscilloscope, don´t throw away that vintage TV!, it is a great source of analog parts. The flyback transformer can be used to make a high voltage power supply, and you also get some nice high voltage capacitors (both electrolytic and mylar ones), the horizontal output transistor which is a high voltage one, ferrite transformers, magnet wire, plus a lot of other small parts. Other uses for old TV sets that you may want to try is to convert your TV into a gaming console, or  an audio synthesizer controlled by drawing with a light-sensitive pen on a CRT television.

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