Hackaday Links: April 7, 2019

April 7, 2019 by Brian Benchoff 5 Comments

It’s April, which means all the people responsible for doubling the number of badges at DEF CON are hard at work getting their prototypes ready and trying to fund the entire thing. The first one out of the gate is Da Bomb, by [netik] and his crew. This is the same team that brought you the Ides of DEF CON badge, a blinky wearable multiplayer game that’s SPQR AF. Da Bomb is now a Kickstarter campaign to get the funding for the run of 500, and you’re getting a wearable badge filled with puzzles, Easter eggs, and a radio-based sea battle game that obviously can’t be called Battleship, because the navy doesn’t have battleships anymore.

Speaking of badges and various badge paraphernalia, there’s a new standard for add-ons this year. The Shitty Add-On V.1.69bis standard adds two pins and a very secure shrouded connector that solves all the problems of last year’s standard. [AND!XOR] just released a Shitty Brooch that powers all Shitty Add-Ons with a CR2032 battery. All the files are up on the Gits, so have fun.

You can 3D print anything if you don’t mind dealing with supports. But how to remove supports? For that [CCecil] has a great tip: use Chap stick. This is a print that used supports and it’s perfectly clean, right off the bed. By inserting a suspend (M600) command at the z-height of the top of the interface layer, then adding Chap stick on the top layer, everything comes off clean. Neat.

Speaking of 3D printing, here’s a project for anyone with the patience to do some serious modeling. It’s a pocket Soviet record player, although I think it’s more properly called a gramophone. It’s crank powered, so there’s a spring in there somewhere, and it’s entirely acoustic with zero electronics. Yes, you’re going to need a needle, but I’d be very interested in seeing somebody remake this using modern tools and construction materials.

Make Your Own MIDI Controller With An Arduino

April 6, 2019 by Brian Benchoff 10 Comments

Engineers create something out of nothing, and no where is this more apparent than in the creation of customized computer hardware. To make a simple MIDI controller, you need knowledge of firmware design and computer architecture, you need knowledge of mechanical design, and you need to know electronic design. And then you need the actual working knowledge and experience to wield a tool, be it a hammer, laser cutter, or an IDE. [Mega Das] brought together all of these skill to build a MIDI controller. Sure, it’s for bleeps and bloops coming out of a speaker, but take a step back and realize just how awesome it is that any one person could imagine, then implement such a device.

The electronics for this build include a printed circuit board that serves to break out the connections on an Arduino nano to a dozen arcade push buttons, four slide pots, two rotary pots, and a handful of screw terminals to connect everything together. Mechanically, this is a laser-cut box engraved with some fancy graphics and sized perfectly to put everything inside.

Yes, we’ve seen a lot of MIDI controllers built around the Arduino over the years, but this one is in a class by itself. This is taking off-the-shelf parts and customizing them to exactly what you want, and a prodigious example of what is possible with DIY hardware creation. You can check out the build video below.

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Tomography Through An Infinite Grid Of Resistors

April 6, 2019 by Brian Benchoff 47 Comments

One of the vast untapped potentials of medicine is the access to imaging equipment. A billion people have difficulty getting access to an x-ray, and that says nothing about access to MRIs or CAT scans. Over the past few years, [Jean Rintoul] has been working on a low-cost way to image the inside of a human body using nothing more than a few electrodes. It can be done cheaply and easily, and it’s one of the most innovative ways of bringing medical imaging to the masses. Now, this is a crowdfunding project, aiming to provide safe, accessible medical imaging to everyone.

It’s called Spectra, and uses electrical impedance tomography to image the inside of a chest cavity, the dielectric spectrum of a bone, or the interior of a strawberry. Spectra does this by wrapping an electrode around a part of the body and sending out small AC currents. These small currents are reconstructed using tomographic techniques, imaging a cross-section of a body.

[Jean] gave a talk about Spectra at last year’s Hackaday Superconference, and if you want to look at the forefront of affordable medical technology, you needn’t look any further. Simply by sending an AC wave of around 10kHz through a body, software can reconstruct the internals. Everything from lung volume to muscle and fat mass to cancers can be detected with this equipment. You still need a tech or MD to interpret the data, but this is a great way to bring medical imaging technology to the people who need it.

Right now, the Spectra is up on Crowd Supply, with a board that can be configured to use 32 electrodes. Measurements are taken at 160,000 samples/sec, and these samples have 16-bit resolution. This is just the acquisition hardware, though, but the software to do tomographic reconstruction is open source and also readily available.

In terms of bringing medical imaging to the masses, this is a very impressive piece of work, and is probably the project from last year’s Hackaday Prize that has the best chance of changing the world.

CNC Your Own PCBs With A 3D Printed Mill

April 5, 2019 by Brian Benchoff 31 Comments

Yes, you can whip up a design for a printed circuit board, send it out to one of the many fab houses, and receive a finished, completed board in a week or two. There are quick-turn assembly houses that will manufacture a circuit board and populate it for you. But sometimes you need a board now, and that’s when we get into home PCB fabrication. You can do this with either etching or milling, but [Renzo] has a great solution. He built a 3D printed milling machine that will make a printed circuit board.

The design of this tiny micro mill is based on a handheld rotary tool, also called a Dremel, but that’s like Kleenex, so just buy a Proxxon. This mill is designed with 3D printed T-track and constructed with linear bearings on smooth rods with standard NEMA 17 stepper motors and herringbone gears for little to no backlash. There is quite a bit going on here, but lucky for us [Renzo] has a video tutorial of the entire build process available for viewing below.

We’ve previously seen some of [Renzo]’s previous efforts in homemade PCB fabrication, up to and including applying green soldermask with the help of Fritzing. This is good, very good, and the only thing that really separates this from manufactured PCBs is the lack of plated through holes. That’s just a bit of graphite and electroplating away, and we’re looking forward to [Renzo]’s further adventures in making PCBs at home.

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Print Your Own Large Format Camera

April 4, 2019 by Brian Benchoff 32 Comments

Just like how vinyl records are seeing a resurgence in an era of digital streaming music, we’re also seeing a lot of people interested in another technology that is as obsolete as it is perfected. The large format camera is back as a kit, it makes huge images, and there’s an Open Source version if you want to print your own.

The Standard 4×5 is a project to build an affordable, lightweight, 3D printed large format camera. It was a Kickstarter project last year, and after a lot of work the project has now been improved with better rails, better bellows, and a lot of refinements.

As an Open Source project, this camera has all the models available, dimensioned drawings for all the metal parts, and a lot of patience required to make your own bellows. With this, you can screw a lens on take a picture, just make sure you get the focus right with some ground glass beforehand.

As for why anyone would want a large format camera, there are a few things that big cameras with tiny apertures can do that nothing else can. Here’s the pinhole solution for the Standard 4×5 with a laser drilled hole, and with this camera you’re getting an f-stop between f/240 and f/520.

Phone For Hackers Launches A Crowdfunding Campaign

April 3, 2019 by Brian Benchoff 26 Comments

Based on the WiFi / Bluetooth wunderchip, clad in a polycarbonate frame, and looking like something that would be an amazing cell phone for 2005, the WiPhone is now available on Kickstarter.

We’ve seen the WiPhone before, and it’s an interesting set of features for what is effectively an ESP32 board with some buttons and a screen. It’s become something of a platform, with expansion daughterboards for LTE, LoRa, a camera, a Bus Pirate, and a programmable NFC/RFID doohickey. If you’ve longed for the day of big ‘ol Nokia brick phones, want to hack your phone, but don’t really care about actually having cellular connectivity, this is something that’s right up your alley.

Although the WiPhone looks like a usable product that was designed by someone with a sense of design, it still is Open Source. You can build your own, and there are dozens of expansion boards that will plug into the back of the WiPhone for prototyping, experimentation, and RGB Gaming LEDs. There’s no cellular modem on the WiPhone, though; for calls you’ll have to turn to SIP or VoIP apps.

Considering how difficult it is to source a cellular modem in small quantities and the desire for a cell phone that respects your Right to Repair, we’ve got to hand it to the WiPhone for creating something people want. It gets even better when you consider this looks more like a product than the 3D printed pieces of electronic cruft we usually see, and we’re happy to see this crowdfunding campaign just passed its goal and is completely funded.

The Repair And Refurbishment Of Silicone Keyboards

April 3, 2019 by Brian Benchoff 19 Comments

There are a lot of retrocomputers out there sitting in garages and attics, and most of them need work. After thirty or forty years, you’re looking at a lot of corrosion, leaking caps, and general wear and tear. When it comes to extreme refurbishment, we haven’t seen anyone better than [Drygol], and this time he’s back with an exceptional example of how far repair and refurbishment can go. He’s repairing the silicone keyboard of a Commodore 116 using some very interesting techniques, and something that opens up the door to anyone building their own silicone keypad.

This project comes from from a member of a demoscene group that found an old C116 that needed a lot of work. The C116 shipped with a silicone membrane keyboard instead of the mechanical keyswitches of the C64 and other, higher-end computers. Unfortunately, this silicone keypad had a few keys ripped out of it. No one, as far as we can tell, has ever figured out how to make these silicone keypads from scratch, but [Drygol] did come up with a way to replace the ripped and missing keys. The process starts with making a silicone mold of the existing keyboard, then casting silicone into the negative of that mold. After a few attempts , [Drygol] had a custom silicone button that matched the shape and color of the original C116 keyboard. The only thing left to do was to attach tiny conductive carbon pads to the bottom of the newly cast buttons and fit them into the existing keyboard.

This is an interesting refurbishment, because there are a lot of vintage computers that used silicone keyboards in the place of mechanical keyswitches. The Speccy, The Commodore TED machines, and a lot of vintage calculators all used silicone keyboards. Until now, no one has figured out how to make DIY silicone keypads, and repairing silicone was out of the question. [Drygol]’s attempt isn’t perfect — it needs key labels, but screen or pad printing will take care of that — but it’s the best we’ve seen yet and opens the doors to a lot of interesting projects in the world of vintage computer repair.