Machining With Electricity Explored In The Hack Chat

January 20, 2023 by Tom Nardi 16 Comments

As a Hackaday reader, it’s safe to assume you’ve got a better than average understanding of electricity. There’s also an excellent chance you’re familiar with machining, and may even have a lathe or old mill in the workshop. But combining the two, and actually machining a piece of metal with electricity, isn’t something that many home gamers can boast first-hand experience with.

Of course, that doesn’t mean there isn’t an interest. To help answer the burning (or at least, sparking) questions from the community, CEO and founder of Voxel Innovations Daniel Herrington stopped by this week’s Hack Chat to talk about the cutting edge of both electric discharge machining (EDM) and the closely related field of electrochemical machining (ECM). While his company uses the technology to produce components at incredible scales, Daniel got his start tinkering in the garage like so many of us, enabling him to provide both a professional and hobbyist prospective on the technologies.

Naturally, the first big question to be addressed was the difference between EDM and ECM. Put simply, electric discharge machining uses high-voltage to literally blast away material from the workpiece. The resulting finish is generally rough, and progress through the material tends to be slow, but it’s relatively simple to implement.

In contrast electrochemical machining could be thought of as a sort of reverse electroplating process, as the material being removed from the workpiece is dissolved and transferred to the cathode — though in practice the flow of pressurized electrolyte keeps it from actually plating the negatively charged tool. ECM is a faster process than EDM and allows for an exceptionally smooth surface finish, but is considerably more challenging from a technical perspective. Continue reading “Machining With Electricity Explored In The Hack Chat” →

Resurrecting PONG, One Jumper Wire At A Time

December 14, 2022 by Ryan Flowers 18 Comments

Between 1976 and 1978, over one million Coleco Telstar video game consoles were sold. The Killer App that made them so desirable? PONG. Yep, those two paddles bouncing a ball around a blocky tennis court were all the rage and helped usher in a new era. And as [Dave] of Dave’s Garage shows us in the video below the break, the bringing the old console back to life proved simpler than expected!

Thankfully, the console is built around what [Dave] quite aptly calls “PONG on a chip”, the General Instrument AY-3-8500 which was designed to make mass production of consoles possible. The chip actually contains several games, although PONG was the only one in use on the Coleco.

After removing the CPU from the non-functional console, [Dave] breathed life into it by providing a 2 MHz clock signal that was generated by an Arduino, of all things. A typical 2N2222 amplifies the audio, and a quick power up showed that the chip was working and generating audio.

Video is smartly taken care of just as it was in the original design, by combining various signals with a 4072 OR gate. With various video elements and synchronization patterns combined into a composite video signal, [Dave] was able to see the game on screen, but then realized that he’d need to design some “paddles”. We’ll leave that up to you to watch in the video, but make sure to check the comments section for more information on the design.

Is a breadboarded PONG console not retro enough for you? Then check out this old school mechanical version that was found languishing in a thrift store.

Continue reading “Resurrecting PONG, One Jumper Wire At A Time” →

The Seven-Segment Display That’s Also An Input Device

November 5, 2022 by Dan Maloney 1 Comment

We’re used to seeing all manner of seven-segment displays, be they mechanical, electronic, or something in between. But what all these displays have in common is that they’re, you know, displays. Using them as inputs would just be crazy talk, right?

Perhaps, but we like where [Dave Ehnebuske] is going with “InSlide,” the seven-segment input device. The idea for this comes from the “DigiTag” display, which we covered back in October, and divides a standard seven-segment character into three vertical strips — two skinny ones for the outside vertical segments, and one wide strip holding the horizontal elements. By sliding these strips up and down relative to each other, the standard nine digits, plus a few other characters, can be composed.

[Dave]’s take on this theme started by building his display from laser-cut plywood pieces, which is a nice choice because of the good contrast between the white wood and the engraver segments. Next, he embedded rare earth magnets in the slides and installed seven Hall effect sensors in the frame. The sensors are connected to an Arduino Nano via a 74HC165 parallel-load shift register, which lets multiple modules be daisy-chained together. He also built an Arduino library to read the current state of the segments; it supports the full hexadecimal character set, or even duodecimal if you like.

[Dave] has shared the library, and it looks like you can get the build files for the mechanism from the original project. That’s good, because this looks ripe for hacking. It looks like it would be pretty easy to motorize a display like this by adding rack-and-pinion gearing and steppers — something like that could make an interesting clock.

Walnut Case Sets This Custom Arduino-Powered RPN Calculator Apart From The Crowd

November 3, 2022 by Dan Maloney 12 Comments

How many of us have an everyday tool that’s truly unique? Likely not many of us; take a look around your desk and turn out your pockets, but more often than not, what you’ll find is that everything you have is something that pretty much everyone else on the planet could have bought too. But not so if you’ve got this beautiful custom RPN calculator in a wooden case.

This one comes to us from [Shinsaku Hiura], who generally dazzles us with unique mechanical clocks and displays. This calculator solves a more practical problem — the dearth of RPN calculators on the market with the correct keyboard feel, specifically with the large keys and light touch he desired. Appropriately, the build started with a numeric keypad, which once liberated of its USB interface was reverse-engineered to figure out how the matrix was wired. Next up, a custom PCB to connect the keypad to an Arduino and a 20×4 LCD display was milled up, while a test case was designed and printed to check fitment. The final case was milled from a block of solid walnut and fitted with an acrylic window, for a sharp look with clean lines and pleasing colors.

As for the calculator itself, the demo below shows it going through its paces. The code is clever because it leverages the minimal number of keys available by hiding all the scientific and engineering functions behind a “secret silver key” that was once the equals key and obviously not needed in RPN. Hats off to [Shinsaku] for a handsome and unique addition to his desk.

Continue reading “Walnut Case Sets This Custom Arduino-Powered RPN Calculator Apart From The Crowd” →

M.2 For Hackers – Connectors

November 3, 2022 by Arya Voronova 9 Comments

In the first M.2 article, I’ve described real-world types and usecases of M.2 devices, so that you don’t get confused when dealing with various cards and ports available out there. I’ve also designed quite a few M.2 cards and card-accepting adapters myself. And today, I’d like to tell you everything you need to know in order to build M.2 tech on your own.

There’s two sides to building with M.2 – adding M.2 sockets onto your PCBs, and building the PCBs that are M.2 cards. I’ll cover both of these, starting with the former, and knowing how to deal with M.2 sockets might be the only thing you ever need. Apart from what I’ll be describing, there’s some decent guides you can learn bits and pieces from, like the Sparkfun MicroMod design guide, most of which is MicroMod-specific but includes quite a few M.2 tips and tricks too.

First, Let’s Talk About The Y-Key

What could you do with a M.2 socket on your PCB? For a start, many tasty hobbyist-friendly SoMs and CPUs now have a PCIe interface accessible, and if you’re building a development board or a simple breakout, an M.2 socket will let you connect an NVMe SSD for all your high-speed low-power storage needs – many Raspberry Pi Compute Module mainboards have M.2 M-key sockets specifically for that, and there’s NVMe support in the RPi firmware to boot. Plus, you can always plug a full-sized PCIe adapter or an extender into such a socket and connect a PCIe network card or other much-needed device – even perhaps, an external GPU! However, as much as PCIe-equipped SoMs are tasty, they’re far from the only reason to use M.2 sockets.

Continue reading “M.2 For Hackers – Connectors” →

A digital caliper connected to a tablet computer

Custom Interface Adds USB And Wi-Fi To Digital Calipers

October 17, 2022 by Robin Kearey 25 Comments

Although old-school machinists typically prefer the mechanical vernier scale on their trusty calipers, many users nowadays buy calipers with a digital readout. These models often come with additional features like differential measurements, or a “hold” function for those situations where you have to maneuver the instrument somewhere deep inside a machine. Another useful feature is a data link that lets you log your measurements on a computer directly instead of manually entering all the values.

The VINCA-branded caliper that [Liba2k] bought has such a data link feature, which requires a USB adapter that’s sold separately. There is a micro-USB connector on the tool itself, but instead of implementing a USB interface, this is used to carry a proprietary serial protocol — a design decision that ought to be classified as a felony if you ask us. Rather than buying the official USB adapter, [Liba2k] decoded the protocol and built his own interface called VINCA Reader that can connect through either USB or Wi-Fi.

The serial format turned out to be a simple serial bus that clocks out 24 bits at a time. In order to adapt its 1.2 V signal level to the 3.3 V used by an ESP32, [Liba2k] designed a simple level shifter circuit using a handful of discrete components. The ESP can communicate with the computer through its Wi-Fi interface, for which [Liba2k] wrote a spreadsheet-like application; alternatively, an ordinary USB cable can be connected to emulate a keyboard for use with any other software.

With its added Wi-Fi feature, the VINCA Reader is actually more complete than the official USB adapter, and will probably be cheaper as well. The serial interface appears to be common to all caliper manufacturers, although many went for a more sensible connector than micro-USB. An automated readout system is particularly handy if you have to make thousands of similar measurements.

Hackaday Podcast 189: Seven Segments Three Ways, Candle Code, DIY E-Readers, And The Badge Reveal

October 14, 2022 by Tom Nardi 4 Comments

This week Hackaday Editor-in-Chief Elliot Williams and Managing Editor Tom Nardi will discuss the return of the East Coast RepRap Festival, the scientific application of slices of baloney, and the state of the art in homebrew e-readers. The discussion weaves its way through various reimaginings of the seven (or more) segment display, an impressive illuminated headboard that comes with its own science-fiction film, and the surprising difficulty of getting a blinking LED to actually look like a flame. Stick around to the end to find out why iPhones are freaking out on amusement park rides, and to hear all the details about this year’s Supercon badge.

Direct download your own!