Tumblelog by Soup.io
Newer posts are loading.
You are at the newest post.
Click here to check if anything new just came in.

August 22 2018

Hardware Store White Balance Reference

We live in a time in which taking pictures is preposterously easy: take out your phone (assuming it wasn’t already in your hands), point it at something, and tap the screen. The camera hardware and software in even basic smartphones today is good enough that you don’t need to give it much more thought than that to get decent pictures. But what if you want to do better than just decent?

Ideally you’d take photos lit by high temperature lights, but failing that, you might need to compensate by adjusting the white balance during post-processing. But to accurately adjust white balance you need a pure white reference point in the image. Thanks to some diligent research by the folks at the FastRawViewer blog, we now have a cheap and widely available source for a pure white reference material: PTFE pipe tape.

Alright, we know what you’re thinking: how hard could it be to find a white object? Well, if you’re talking about really white, it can actually be quite difficult. Take a walk down the paint aisle of your local hardware store and see just how many “whites” there actually are. Think the shirt your subject is wearing is really white? Think you can use the glossy white smartphone in their hand as a reference? Think again.

By taking a rubber eraser and wrapping it with a few layers of the PTFE tape, you can create a white reference that’s so cheap it’s effectively disposable. Which is good, because protecting your white reference object and keeping it clean can be a challenge in itself. But with a PTFE tape reference, you can just chuck the thing when the photo shoot is done.

Combine this cheap white reference with some of the DIY photography lighting setups we’ve covered in the past, and you’ll be well on the way to getting better images to document all your projects. Just remember to submit them to us when you’re done.

[Thanks to Keith Olson for the tip.]

If You Are Planning On Building Your Own Space Shuttle…

One of the most complicated machines ever built was the US space shuttle (technically, the STS or Space Transportation System). Despite the title, we doubt anyone is going to duplicate it. However, one of the most interesting things about the shuttle’s avionics — the electronics that operate the machine — is that being a government project there is a ridiculous amount of material available about how it works. NASA has a page that gathers up a description of the vehicle’s avionics. If you are more interested in the actual rocket science, just back up a few levels.

We will warn you, though, that if you’ve never worked on space hardware, some of the design choices will seem strange. There are two reasons for that. First, the environment is very strange. You have to deal with high acceleration, shock, vibration, and radiation, among other things. The other reason is that the amount of time between design and deployment is so long due to testing and just plain red tape that you will almost certainly be deploying with technology that is nearly out of date if not obsolete.

A good example is the orbiter’s GPC or General Purpose Computers. There are five of them — at least three have to agree before they’ll do anything. Early versions of the GPC used magnetic core memory. That technology was old even when it was put in the design but it was the best way during the design phase to ensure the memory would not be upset by radiation effects. In 1991, a major upgrade did replace the core with semiconductor-based memory.

The information on the NASA site is a bit high-level but still detailed. If you want some real hardcore discussions about the shuttle’s avionics, the KLabs site lost NASA funding before moving to a private web server to remain operational. If you ever wanted to try your hand at programming in HAL/S as the shuttle programmers did, you can get the documentation there. There’s also a booklet with a lot of information that you can download from NASA and a video overview you might enjoy, below.

While we doubt anyone will be trying to build their own shuttle, this is still a great wealth of information. Of course, the Russians did try, back in the day and arguably made a better system. If you do build a copy, there’s already a shop manual from Haynes.

 

August 21 2018

Plasma Etching In A Microwave

Deep inside your smartphone are a handful of interesting miniature electromechanical devices. The accelerometer is a MEMS device, and was produced with some of the most impressive industrial processes on the planet. Sometimes, these nanoscale devices are produced with plasma etching, which sounds about as cool as it actually is. Once the domain of impossibly expensive industrial processes, you can now plasma etch materials in a microwave.

Of course, making plasma in this way is nothing new. If you cut a grape in half and plop it in a microwave, some really cool stuff happens. This is just the 6th grade science class demonstration of what a plasma is, and really it’s only a few dissociated water, oxygen, and nitrogen molecules poofing in a microwave. To do something useful with this plasma, you need a slightly more controlled environment.

The researchers behind this paper used a small flask with an evacuated atmosphere (about 300 mTorr) placed into a microwave for a few seconds. The experiments consisted of reducing graphene oxide to graphene, with the successful production of small squares of graphene bonded to PET film. Other experiments changed the optical properties of a zinc oxide film deposited onto a glass microscope slide and changing a PDMS film from being hydroscopic to hydrophobic.

While the results speak for themselves — you can use a microwave to generate plasma, and that plasma can change the properties of any exposed material — this is far from a real industrial process. That said, it’s good enough for an experiment and another neat technique in the home lab’s bag of tricks.

Automated Turntable For 3D Scanning

Those just starting out in 3D printing often believe that their next major purchase after the printer will be a 3D scanner. If you’re going to get something that can print a three dimensional model, why not get something that can create said models from real-world objects? But the reality is that only a small percentage ever follow through with buying the scanner; primarily because they are notoriously expensive, but also because the scanned models often require a lot of cleanup work to be usable anyway.

While this project by [Travis Antoniello] won’t make it any easier to utilize scanned 3D models, it definitely makes them cheaper to acquire. So at least that’s half the battle. Consisting primarily of a stepper motor, an Arduino, and a EasyDriver controller, this is a project you might be able to assemble from the parts bin. Assuming you’ve got a pretty decent camera in there, anyway…

The general idea is to place a platform on the stepper motor, and have the Arduino rotate it 10 degrees at a time in front of a camera on a tripod. The camera is triggered by an IR LED on one of the Arduino’s digital pins, so that it takes a picture each time the platform rotates. There are configurable values to give the object time to settle down after rotation, and a delay to give the camera time to take the picture and get ready for the next one.

Once all the pictures have been taken, they are loaded into special software to perform what’s known as photogrammetry. By compiling all of the images together, the software is able to generate a fairly accurate 3D image. It might not have the resolution to make a 1:1 copy of a broken part, but it can help shave some modeling time when working with complex objects.

We’ve previously covered the use of photogrammetry to design 3D printed accessories, as well as a slightly different take on an automated turntable a few years ago. The process is still not too common, but the barriers to giving it a try on your own are at least getting lower.

Turning Everything Into A Tap Controller

Our entire life is staring at glowing rectangles, and all our surroundings are hard, flat surfaces. [Ben] had the idea to turn those flat surfaces into a generic tap interface controller, and his project for the Hackaday Prize might just do that.

Some of the prior art that went into this project includes Ping Pong Plus Plus, an augmented-reality-ish implementation of ping pong that puts projected light wherever a ping pong ball hits the table. The game does this by mounting piezos to the bottom of a table and just a slight bit of math to determine where on the table the ball hit. There’s also MicLoc, a door lock that responds to knocking.

With this prior art, it’s all about microcontrollers and peripherals, and for that, [Ben] turned to the STM32F303RE, which sports four very fast ADCs and op-amps. There’s a lot of DMA usage on there, and the code is using a ton of signal processing. The important bit here is finding the difference between whatever the tabletop equivalent to an earthquake’s P-waves and S-waves are — [Ben] only wants the first bit of a waveform that travels through the table longitudinally, not the much louder vibrations of the entire table.

If [Ben] manages to put this together, an entire wall could be a light switch or a dimmer. You could add a secret knock to your door, and your desk could control your computer. It’s a promising idea, and the engineering that’s going into this project is just fantastic.

The HackadayPrize2018 is Sponsored by:

Microchip

Digi-Key

Supplyframe

All the Badges of DEF CON 26 (vol 2)

There were so many amazing unofficial badges at DEF CON this year that I can’t possibly cover them all in one shot. I tried to see every badge and speak with every badge maker — like a hardware safari. Join me after the jump for about fourteen more badges that I saw at DEF CON 26!

If you missed the first batch, check those badges out too — there’s even a Badgelife Documentary that you need to add to your watch list. Okay, let’s dig in.

DC Furs Badge

With so many creative hardware badges it’s pretty impossible to narrow it down to a favorite, but the DCFurs badge is pretty close to the best this year. One of the things I like about it is the art that gives it the iconic look. As far as I know this is original and not borrowed from pop culture. The combination of gold-plated copper, matte black solder mask, and white silk screen is used in a lot of badges but it really pops with this design. Finally, the simple yet interesting design of the display made for some really interesting patterns, and it’s still dense enough to scroll text really well.

The group made 600 of these badges, building on an STM32F411 because it runs MicroPython. This is used for the visualizations shown on the screen, while the puzzles and hardware abstraction layers are written in C.

Amulet Clock

The amulet clock isn’t quite a badge, but it’s cool enough (and close enough) to mention here. It uses a VFD display for the time, running at -30V. The power supply design and having it that close to your neck, are both a bit fascinating but too complicated to go into detail here. The creator of this clock is hoping to get the design into an article for POC||GTFO so hopefully we’ll get to read about before long.

Mr Robot Badge

The MrRobotBadge was once again a hot commodity at DEF CON 26. The art side of the badge is based on the mascot of anti-everything from the television show of the same name.

This year’s badge has greatly increased the size of the display. The ESP8266 driving the badge couldn’t possibly keep up with the display, but the use of the IS31FL3741 display driver makes it possible. It takes I2C commands and in turn handles the scanning of a matrix as large as 39×9. In this case the LED matrix on the badge is 18×18, with a d-pad to the left and two buttons to the right (classic NES style).

You can reprogram the badge using a serial to USB cable. One of the cooler hacks I’ve seen on the badge is this example of Conway’s Game of Life.

Dragonfly 2 Badge

The Dragonfly badge returned to DEF CON this year. You can hear the story of last year’s badge from Kerry’s talk on the topic. Having learned his lesson regarding hand assembly, this year he panelized the badges and had them professionally assembled.

In keeping with the original, the Dragonfly badges communicate with each other using IR, synchronizing when they’re in groups. (The concept comes from Neal Stephenson’s book The Diamond Age.) Although they have a lot more LEDs this year, the two versions are still compatible when it comes to those sync messages.

Kerry included add-on headers and the badge he was wearing around was sporting a taco, a squid face, a Santa hat and a small fries. Perhaps the award for best distribution of multiple add-ons should got to this design!

DEAUTH Badge

I think this is the only non-electronic badge I looked into covering this year. Sorry for failing to get it in focus, the bejeweled badge is giving the auto-focus a tough time. That’s because it’s super reflective. El Kentaro told me the badge itself is 3D printed, smoothed, and then covered in multiple coats of gold spray paint. The inset is not just large jewels, but hundreds of tiny glass beats to fill in the gaps between the larger stones.

Queercon 15 Badge

We already ran an in-depth teardown of the Queercon badge so I won’t go down that road again here. It was the most polished of all the designs I saw at DC26. If you made it to the Hardware Hacking Village, you may have seen MaraJade’s badge repair Kiosk set up with everything you’d need to repair untold numbers of badges. When I stopped by, she showed me an interesting tidbit I hadn’t yet seen: the cake recipe from Portal is part of the “LAB” faceplate design, in micro-lettering on the copper layer. neat!

There are all kinds of secrets about the Queercon 15 badge available now that the con has passed. It’s definitely worth a look.

Blinky Ball (RGB) Badge

Just thinking about the power supply requirements of this giant RGB LED ball makes my head hurt. The product of hackers from LA’s Null Space Labs, I think this is the 320 LED version (16 slices with 20 RGB LEDS per slice) but they have a 384 LED version in the works too. Check out their Hackaday.io project for more info — it seems they’re in the middle of Crowdfunding a production run of these.

Viking Ship Badge

This badge again makes use of the matte-black/gold/white very well but adds to it one additional color of red. The design uses it all in perfect proportion, and adds in white LEDs to make up the constellations. This is the work of Thomas Flummer who designed the BornHack badges for last year and this year (wrapping up later this week). This badge looks spectacular so it’s no surprise this isn’t his first rodeo.

Most interesting to me is the inspiration Thomas pulled from other badgemakers. In his writeup he mentions the inspiration he drew from Kerry Scharfglass’ Dragonfly badges which “didn’t focus on skulls” — focusing instead on something that is beautiful and not a play on black T-shirts and the accoutrement that go with them. He also took Joe Grand’s Optical Spy idea and ran with it… there’s data hidden in those LEDs!

0x0G Badge

Apparently Google has an event at Blackhat/DEF CON each year that I had never heard of it until I ran into TwitchyLiquid64. The badge is designed to look like a casino chip, with LEDs lining the circumference. 520 of them were made and each has an IR receiver and LED, letting the badges change one another’s patterns. I thought it was neat that TwitchyLiquid was using a remote control like you’d see with an LED strip to easily control the badges. Check out more details on the badge’s repository.

Crazy Name-Tag Badge

No time to spin boards for your custom badge? #Badgelife finds a way. I loved seeing this custom name tag badge from Gigs. He said he decided about a week before the con to build something and this is what came out. It’s a hunk of protoboard, four batteries, two supercaps for smoothing the load, and 67 LEDs in parallel. Oh yeah, and no resistors. It only has to last one weekend after all!

Hacker Warehouse Badge

The Hacker Warehouse badge is a beautifully clean design. I find it interesting how some boards look obviously like PCBs and others, like this one, end up looking more like a finished good. The text and graphics came out so nicely you almost expect the electronics to be hidden behind this face plate.

This badge is packing everything plus the kitchen sink in terms of USB and WiFi penetration testing. One of the hard things about trying to see all the badges is that you fall into the trap of visiting with the people and forgetting to talk about the badge. So is the case with this one, but we’re in luck that Brian Benchoff already did an in-depth review that shares all of the details.

DC Darknet Badge

I’m always anxious to get my hands on the DEF CON Darknet badge each year. It exists is to take part in a set of crypto puzzles designed both to welcome in beginners (me, I suck an crypto puzzles but want to get better) and veterans alike. This is the first year that I can remember an abundance of badges being available.

This year’s badge is called Cdmc0de (command code) and there were over 1200 made. They come in kit form, and that took about 3 nights for a volunteer crew to get everything into bags. The PCB itself has all of the surface-mount components already installed, including the STM32 and ESP32 which are both included in the design. This is the first year the Darknet badges have used a custom programming jig and it is said to have made the flashing process a dream.

Once assembled there are two screens, an OLED that is narrow and long, and a larger LCD screen. Badges are able to interact with each other, based on selections from a user menu based on a D-pad and two button (Classic NES again) user interface. Thar’ be puzzles inside but I have yet to take them on.

The GoodFear Blimp

This is an awesome badge that didn’t quite get across the finish line. As you can see, it’s designed to look like the Goodyear Blimp, adorned with several hundred LEDs. At about 7 inches across, it would have made a formidable addition to your lanyard-mounted bling. Unfortunately, time ran out before the project got to the firmware phase, but the hardware is all there.

That didn’t stop Chris Gammell from having some hardware fun. With time running out he also rolled an add-on. Based on the super popular “This is Not a Camera” stickers from DC25, he built an add-on shaped like a surveillance camera and spent DC26 handing out boards.

DC503 Badge

The DC503 badge is one that I look for every year. Ostensibly it’s built for Portland-area hackers but I think there’s such a huge following of the DC503 group that they don’t really care where you’re from if you want to be part of this awesome crowd that gathers in Portland once a month, and every year for a party at DC.

This year the key feature of the badge is a 3D printed diffuser that hinges around your wrist. Inside is an RGB LED strip that looks great spinning patterns through the while plastic. The single driver board sandwiches between you and the diffuser. They were everywhere at the bumpin’ 503 party. Other than that I have no more info on this one. Anyone in the know, please leave details in the comments below.

Once More Before the Dawn

The DEF CON badge anthology for this year isn’t closed yet. I think I can get through the rest of the badges I saw at the con in one more giant installment. Keep your eye on Hackaday!

Blink A Pi, Win A Prize

You can plug in a Raspberry Pi, and you can blink a LED. You can visualize data, and now there’s a contest on Hackaday.io to show off your skills. Right now, we’re opening up the Visualize It With Pi contest on Hackaday.io. The challenge? Visualize data with LED strips and panels. Is that ‘data’ actually just a video of Never Gonna Give You Up? We’ll find out soon enough.

The goal of this contest is to combine a Raspberry Pi and its immense processing power and the blinky goodness of LED strips and panels to visualize and interpret data in novel and artistic ways. We’re looking for animation. clarity, and flamboyant flickering. Want some ideas? Check out the World of Light or the American Constitution Candle. We’re looking for the most blinky you can do with a Pi, and yes, there will be prizes.

Prizes

BlinkyTile Explorers Kit

Prizes for the best blinky include, of course, more blinky. The best visualizations from a directly connected sensor, data from an Internet Source, and data from an esoteric data source will each receive some Blinkytape. This is a strip of WS2812b LEDs with an ATMega32u4 embedded on the end. Plug a USB power supply into the Blinkytape, and you get a strip of LEDs in whatever color you want with the ability to push animation frames to the chip on the strip. The Grand Prize winner for this contest will also receive Blinkytile Explorers Kit, a Serpentine LED strip, a LED ring, and two meters of ultra thin LED strip.

Let’s Do This!

The requirements for the contest are simple: just use a Raspberry Pi to drive LED strips or panels, post it as a new project on Hackaday.io, and submit the project to the contest. We’re looking for a full description, source, schematics, and photos and videos of the finished version of the project — do everything you can to show off your work! The contest is open right now, and ends at 08:00 Pacific on October 1st. We know you like to blink those LEDs, so get crackin’.

Texture Trick for 3D Prints From the Stone Age

Arguably one of the most difficult aspects of 3D printing is trying to make the finished product look like it wasn’t 3D printed. It can take a lot of time and work to cover up the telltale layer lines (or striations, if you want to get fancy), especially if your 3D printer isn’t perfectly calibrated. While there aren’t many shortcuts to achieve a glass-like finish on 3D printed parts, if your end goal is to make something that looks like stone, [Wekster] has a tip for you.

He demonstrates the technique by building a gorgeous recreation of the main gate from Jurassic Park. The process gives the relatively smooth plastic the gnarled look of rough-hewn stone with very little in the way of manual work. While it’s true there’s no overabundance of projects this stone-look finish will work for, it’s definitely something we’ll be filing away mentally.

So what’s the secret? [Wekster] first coats the 3D printed parts with common wood filler, the sort of stuff available at any hardware store. He then wraps them in clear plastic wrap, allowing the wrap to bunch up rather than trying to pull it taught. For extra detail, he digs into the plastic wrap here and there to create what will appear to be gaps and cracks on the finished piece. The wood filler is then left to dry; a process which normally only takes a few minutes, but now will take considerably longer as the plastic wrap will be keeping the air from it.

Once its hardened and unwrapped, [Wekster] sprays it with a base coat of color, and follows up with a few washings with watered down black and gray paints. This technique is well known to anyone who’s done miniature or model painting; serving to highlight the surface texture and give the finish more depth. With this method, anything that resembles a layer line in the print is long gone, and the surface looks so complex and detailed that at first glance few would believe it’s plastic.

[Wekster] also used wood filler during the finishing process for his Fallout 4 “Thirst Zapper” replica. In the past we’ve shown how you can smooth out 3D printed parts with epoxy and taken a very scientific look at using UV resin as a conformal coating, but maybe it’s time we give wood filler a shot.

Kathleen Booth: Assembling Early Computers While Inventing Assembly

Imagine having to program your computer by rewiring it. For a brief period of time around the mid-1940s, the first general-purpose electronic computers worked that way. Computers like ENIAC initially had no internal storage for code. Programming it involved manipulating thousands of switches and cables. The positions of those switches and cables were the program.

Kathleen Booth began working on computers just as the idea of storing the program internally was starting to permeate through the small set of people building computers. As a result, she was one of the first programmers to work on software and is credited with inventing assembly language. But she also got her hands dirty with the hardware, having built a large portion of the computers which she programmed. She also did some early work with natural language processing and neural networks. And this was all before 1962, making her truly a pioneer. This then is her tale.

Early Years

Kathleen Booth was born Kathleen Britten in 1922 in Stourbridge, Worcestershire, England. She got a B.Sc. in Mathematics from the University of London and a Ph.D. in Applied Mathematics in 1950. There weren’t any computer degrees to be had as of yet. From 1944 to 1946 she was a Junior Scientific Office at the Royal Aircraft Establishment and then from 1946 to 1952, a Research Scientist at the British Rubber Producer’s Research Association (BRPRA). Also in 1946, she started work as a research assistant at Birkbeck College, University of London, later becoming a Research Fellow and Lecturer.

Building Computers At Birkbeck College

Kathleen, Xenia Sweeting and Andrew working on the ARC in 1946 Kathleen, Xenia Sweeting and Andrew working on the ARC in 1946, Source: Birkbeck

At Birkbeck, computer research was being done by Andrew Booth whom Kathleen would eventually marry. Andrew had previously done X-ray crystallography research at the University of Birmingham and that included doing a lot of computations. This started him down the path of building computing machines to make the work easier. He next spent a short time as a research physicist at the BRPRA where he began work on the ARC, the Automatic Relay Computer (sometimes referred to as the Automatic Relay Calculator). This used paper tape for input and was really a special purpose computer serving as a Fourier synthesizer.

In 1946 he took up a post as a Nuffield fellow at Birkbeck. He continued work on the ARC but as there was no room at the College, and since the BRPRA was funding it, the work was done at their facilities. It was then that he met Kathleen. Kathleen and another research assistant, Xenia Sweeting, helped Andrew continue building the ARC and in fact did most of the construction.

6 Months In Princeton

Von Neumann architecture/stored program architectureIn 1945, John von Neumann wrote a document called the First Draft of a Report on the EDVAC wherein he described what became known as the von Neumann architecture for a computer. In it, he defines the parts of a computer and in particular that program is stored in the computer’s memory. For that reason, it’s also sometimes called the stored-program computer.

In 1947, through funding from the Rockefeller Foundation and the BRPRA, Andrew and Katheleen took a 6 month US tour with von Neumann whom Andrew had met during a previous visit. The tour was based in Princeton, New Jersey at the Institute for Advanced Study.

This visit was also the first time that the Booth’s had heard of the von Neumann architecture. It led Andrew to redesign the ARC, designing the relay part of the machine in only 2 months, coming up with what is sometimes referred to as the ARC2. Still in 1947, Kathleen and he also wrote up two reports about it, General considerations in the design of an all-purpose electronic digital computer and Coding for A.R.C.. The first of those reports was widely circulated and even underwent a 2nd edition. In it, they detailed what’s needed for a von Neumann architecture machine, outlining a number of different options for the memory.

Inventing Early Assembly Language

Contracted notationThe only place I could find Coding for A.R.C. was as a hard copy on the Institute’s shelves, which is unfortunate as it’s usually the reference for where Kathleen first outlined her assembly language, or autocode, for ARC2. She also wrote the assembler for it.

The other report was released around the same time, and while it does give a contracted notation for the ARC2’s machine language, I suspect that this wasn’t the assembly language. In that report, she first explains how the orders, which we now call instructions, are represented by 0s and 1s loaded into some sort of storage. For the ARC2, 10011 was the order to clear the arithmetic register and transfer a value from memory into the register. Today, we call this machine language. In contracted notation, she then gives the same order as M -> cR.

The Electronic Computers

Andrew Booth’s next computer was entirely electronic and called the SEC (Simple Electronic Computer). That was followed by the APE(*)C (All Purpose Electronic Computer) where the * was to be replaced by a letter representing the sponsor.

Katherine also wrote software for those two computers but unlike with ARC and ARC2, she didn’t do any of the construction.

Natural Language Processing

In 1947, in order to get funding from Rockefeller, the Booth’s added working on natural language processing to their list of projects. The goal was to achieve accurate technical translation and not literary quality. In their book, Automatic Digital Calculators, they outline some of the algorithms which they and collegues had worked on up to 1965, starting out with word substitutions and processing of stems and word endings. While they did a lot of work on NLP at Birkbeck College with their students, there’s also a record of them working on English-French translations for the National Research Council Canada between 1965 and 1972.

French-English translation French-English translation, Source: Birkbeck

Neural Networking In The 1950s

As another example of her pioneering work, the Birkbeck College Annual Report of 1958/59 says that Kathleen wrote a program to simulate a neural network investigating ways in which animals recognize patterns and that the following year’s report mentions her work on a neural network for character recognition. This was only four years after the first running of a neural network on a computer.

Off To Canada

The Booth’s left Birkbeck College in 1962, both moving to Canada to work at the University of Saskatchewan and then at Lakehead University in 1972. She retired from Lakehead in 1978 but an article search shows a paper by her and her son, Dr. Ian J. M. Booth, entitled Using neural nets to identify marine mammals dated 1993 when she would have been 71 and still going strong.

ARM Programming with Bare C

We confess. When starting a microcontroller project, we often start with the last one we did for that environment, copy it, and just make changes. And the first one? It — ahem — might have been found on the Internet. There’s a lot more than just your code that does into this. If you want do (and understand) absolutely everything yourself on an ARM development project, what you want an all-in-one walkthrough. It just so happens [Jacob Mossberg] has a from scratch guide of what you need to do to get your C code running on ARM.

Starting with an ARM Cortex M3, he writes a simple C program and gets the assembly language equivalent. What follows is a detailed analysis of the machine code, exploring what the compiler assumed would be set up. This leads to understanding what the start up code and linker script need to look like.

It is a great approach and reminded us of the old saying about “teach someone how to fish.” He even devotes a little time to talking about getting debugging working with OCD. Of course, the exact details are specific to the chip he’s using, but most of it would apply to any ARM chip. Even if you don’t use ARM, though, the thought process and methodology is itself quite interesting.

This post would be just the thing if you are using Blue Pills and ready to move away from the Arduino ecosystem. Of course, if you don’t want veer away from the Arduino system, but don’t want to go all the way to bare metal, there’s always mBed.

An LED You Can Blow Out, With No Added Sensor

We’d seen it done with buttons, switches, gestures, capacitive touch, and IR remote, but never like this. [electron_plumber] made an LED that can be blown out like a candle, and amazingly it requires no added sensors. The project uses an Arduino to demonstrate turning a tiny LED on and off in response to being blown on, and the only components are the LED and a resistor.

[electron_plumber] used an 0402 LED and thin wires to maximize the temperature responses.How is this done? [electron_plumber] uses an interesting property of diodes (which are the “D” in LED) to use the LED itself as a temperature sensor. A diode’s voltage drop depends on two things: the current that is being driven through the diode, and the temperature. If the current is held constant, then the forward voltage drop changes reliably in response to temperature. Turning the LED on warms it up and blowing on it cools it off, causing measurable changes in the voltage drop across the device. The change isn’t much — only a handful of millivolts — but the effect is consistent and can be measured. This is a principle [Elliot Williams] recently covered in depth: using diodes as temperature sensors.

It’s a clever demo with a two important details to make it work. The first is the LED itself; [electron_plumber] uses a tiny 0402 LED that is mounted on two wires in order to maximize the temperature change caused by blowing on it. The second is the method for detecting changes of only a few millivolts more reliably. By oversampling the Arduino’s ADC, an effectively higher resolution is obtained without adding any hardware or altering the voltage reference. Instead of reading the ADC once, the code reads the ADC 256 times and sums the readings. By working with the larger number, cumulative changes that would not register reliably on a single read can be captured and acted upon. More details are available from [electron_plumber]’s GitHub repository for LEDs as Sensors.

Embedded below is a video that is as wonderful as it is brief. It demonstrates the project in action, takes a “show, don’t tell” approach, and is no longer than it needs to be.

In the past we have seen LEDs that can be blown out like candles in different ways; one used a microphone to detect blowing while another used a thermistor to detect the temperature change from blowing. [electron_plumber]’s project is notable not only for using no added parts, but also for being documented in a way that just about anyone can get up and running, and that’s something we always like to see.

Cheap FPGA Board Roundup

There’s never been a better time to get into using FPGAs. Nearly all vendors have some level of free software and while boards haven’t gotten as cheap as ones with microcontrollers, the prices are way down. [Joel Williams] was frustrated when his board of choice became unavailable, so he decided to compile data on as many cheap boards as he could.

[Joel] covers the major vendors like Intel and Altera. But he also includes information on Actel, Cypress, and Lattice. While the list probably isn’t comprehensive, it is a lot of information about many popular boards. The notes are helpful and point out oddities about the boards in many cases.

We didn’t see our favorite — the Lattice iCeStick — on the list. But there were some boards in the $10 range including the UPDuino, which looks like fun and will stack with an Arduino Nano or Pro. We also saw another of our favorites, the MAX1000 board which is a great little low-cost board.

We liked [Joel’s] comments about not worrying too much about the things you could add easily like serial memory and character LCDs. He suggests you worry more about things that you want that would be hard for you to add yourself, such as an Ethernet port, or HDMI. The list was updated a few months ago and we hope [Joel] will continue to maintain it. He does solicit suggestions.

If you are interested in learning about FPGAs, we have a set of boot camps for you at Hackaday.io, that you might like to check out.

What Will You Do If WWVB Goes Silent?

Buried on page 25 of the 2019 budget proposal for the National Institute of Standards and Technology (NIST), under the heading “Fundamental Measurement, Quantum Science, and Measurement Dissemination”, there’s a short entry that has caused plenty of debate and even a fair deal of anger among those in the amateur radio scene:

NIST will discontinue the dissemination of the U.S. time and frequency via the NIST radio stations in Hawaii and Ft. Collins, CO. These radio stations transmit signals that are used to synchronize consumer electronic products like wall clocks, clock radios, and wristwatches, and may be used in other applications like appliances, cameras, and irrigation controllers.

The NIST stations in Hawaii and Colorado are the home of WWV, WWVH, and WWVB. The oldest of these stations, WWV, has been broadcasting in some form or another since 1920; making it the longest continually operating radio station in the United States. Yet in order to save approximately $6.3 million, these time and frequency standard stations are potentially on the chopping block.

What does that mean for those who don’t live and breathe radio? The loss of WWV and WWVH is probably a non-event for anyone outside of the amateur radio world. In fact, most people probably don’t know they even exist. Today they’re primarily used as frequency standards for calibration purposes, but in recent years have been largely supplanted by low-cost oscillators.

But WWVB on the other hand is used by millions of Americans every day. By NIST’s own estimates, over 50 million timepieces of some form or another automatically synchronize their time using the digital signal that’s been broadcast since 1963. Therein lies the debate: many simply don’t believe that NIST is going to shut down a service that’s still actively being used by so many average Americans.

The problem lies with the ambiguity of the statement. That the older and largely obsolete stations will be shuttered is really no surprise, but because the NIST budget doesn’t specifically state whether or not the more modern WWVB is also included, there’s room for interpretation. Especially since WWVB and WWV are both broadcast from Ft. Collins, Colorado.

What say the good readers of Hackaday? Do you think NIST is going to take down the relatively popular WWVB? Are you still using devices that sync to WWVB, or have they all moved over to pulling their time down over the Internet? If WWVB does go off the air, are you prepared to setup your own pirate time station?

[Thanks to AG6QR for the tip.]

August 20 2018

OMEN Alpha: A DIY 8085-Based Computer

[Martin Malý] has put together a sweet little 8085-based single board computer called OMEN. He needed a simple one for educational purposes, and judging by the schematic we think he’s succeeded.

Now in its fourth iteration, it has a 32K EEPROM, 32K of memory, one serial and three parallel ports. In the ROM he’s put Tiny BASIC and Dave Dunfield’s MON85 Serial Monitor with Roman Borik’s improvements. His early demos include the obligatory blinking LED, playing 8-bit music to a speaker, and also a 7-segment LED display with a hexadecimal keyboard. There is also a system connector which allows you to connect a keyboard, a display, and other peripherals. Of course, you can connect serially at up to 115200 baud, making it very easy to compile some assembly on a PC and use the monitor to paste the hex into the board’s memory and run it. Or you can just jump into the Tiny BASIC interpreter and have some nostalgic fun. He demos all this in the video below.

He’s given enough detail for you to make your own and he also has the boards available in kit form on Tindie for a very reasonable price. With some minimal soldering skills, you can be back in the ’80s in no time.

Part of [Martin’s] interest in these vintage computers stems from his having grown up in the ’80s in Eastern Europe when it was impossible for him to have a computer of his own. We’re glad then that he wrote up his experience with home computers behind the iron curtain as well as the peripherals.

Simple ESP8266 Weather Station using Blynk

Today’s hacker finds themself in a very interesting moment in time. The availability of powerful microcontrollers and standardized sensor modules is such that assembling the hardware for something like an Internet-connected environmental monitor is about as complex as building with LEGO. Hardware has become elementary in many cases, leaving software as the weak link. It’s easy to build the sensor node to collect the data, but how do you display it in a useful and appealing way?

This simple indoor temperature and humidity sensor put together by [Shyam Ravi] shows one possible solution to the problem using Blynk. In the video after the break, he first walks you through wiring the demonstration hardware, and then moves on to creating the Blynk interface. While it might not be the ideal solution for all applications, it does show you how quickly you can go from a handful of components on the bench to displaying useful data.

In addition to the NodeMCU board, [Shyam] adds a DHT11 sensor and SSD1306 OLED display. He’s provided a wiring diagram in the repository along with the Arduino code for the ESP8266, but the hardware side of this demonstration really isn’t that important. You could omit the OLED or switch over to something like a BME280 sensor if you wanted to. The real trick is in the software.

For readers who haven’t played with it before, Blynk is a service that allows you to create GUIs to interact with microcontrollers from anywhere in the world. The code provided by [Shyam] reads the humidity and temperature data from the DHT11 sensor, and “writes” it to the Blynk service. From within the application, you can then visualize that data in a number of ways using the simple drag-and-drop interface.

We’ve seen Blynk and ESP8266 used to control everything from mood lighting to clearance-rack robotic toys. It’s a powerful combination, and something to keep in mind next time you need to knock something together in short order.

Reposted byskizzo skizzo

Rewinding Live Radio

Even though it’s now a forgotten afterthought in the history of broadcasting technology, we often forget how innovative the TiVo was. All this set-top box did was connect a hard drive to a cable box, but the power was incredible: you could pause live TV. You could record shows. You could rewind TV. It was an incredible capability, that no one had ever seen before. Of course, between Amazon and Netflix and YouTube, no one watches TV anymore, and all those platforms have a pause button, but the TiVO was awesome.

There is one bit of broadcasting that still exists. Radio. For his Hackaday Prize entry, [MagicWolfi] is bringing the set-top box to radio. He’s invented the Radio Rewind Button, and it does exactly what you would expect: it rewinds live radio a few minutes.

To have a pause or rewind button on a TV or radio, the only real requirement is a bunch of memory. The TiVO did this with a hard drive, and [MagicWolfi] is doing this with 256 MB of SDRAM. That means he needs to access a ton of RAM, and for that he’s turning to the Digilent ARTY S7 board. Yes, it’s an FPGA, but actually a fairly simple solution to the problem.

The rest of the circuit is an FM receiver chip and an I2S audio codec on an Arduino-shaped daughterboard. The main controller for this project is a big red button that will simply rewind the audio stream a few minutes. There’s no telling exactly how long [MagicWolfi] will be able to rewind the audio stream, but 256 MB is a ton in the audio world.

The HackadayPrize2018 is Sponsored by:

Microchip

Digi-Key

Supplyframe

The Forgotten Art of Riveted Structures

If you are in the habit of seeking out abandoned railways, you may have stood in the shadow of more than one Victorian iron bridge. Massive in construction, these structures have proved to be extremely robust, with many of them still in excellent condition even after years of neglect.

A handsome riveted railway bridge, over the River Avon near Stratford-upon-Avon, UK. A handsome riveted railway bridge, over the River Avon near Stratford-upon-Avon, UK.

When you examine them closely, an immediate difference emerges between them and any modern counterparts, unlike almost all similar metalwork created today they contain no welded joints. Arc welders like reliable electrical supplies were many decades away when they were constructed, so instead they are held together with hundreds of massive rivets. They would have been prefabricated in sections and transported to the site, where they would have been assembled by a riveting gang with a portable forge.

 

So for an audience in 2018, what is a rivet? If you’ve immediately thought of a pop rivet then it shares the function of joining two sheets of material by pulling them tightly together, but differs completely in its construction. These rivets start life as pieces of steel bar formed into pins with one end formed into a mushroom-style dome, probably in a hot drop-forging process.

A rivet is heated to red-hot, then placed through pre-aligned holes in the sheets to be joined, and its straight end is hammered to a mushroom shape to match the domed end. The rivet then cools down and contracts, putting it under tension and drawing the two sheets together very tightly. Tightly enough in fact that it can form a seal against water or high-pressure steam, as shown by iron rivets being used in the construction of ships, or high-pressure boilers. How is this possible? Let’s take a look!

How Rivets are Formed

The above simple description of the process leaves out a few details. Rivet snap and set tools — heavy solid steel formers to fit both the straight and mushroom shaped ends of the rivet — are used on both ends of the rivet, on the mushroom end to hold it in place while it is being hammered, and at the straight end to hammer the sheets together with the snap and form a smooth new mushroom shape with the set. Thus a typical riveting gang such as that working on a railway bridge would have included two people working on the rivet itself, one on either end. Sometimes the person holding the set on the mushroom end would have to crawl into confined spaces such as inside a boiler to perform this task.

In the Victorian era the work would have been all done by hand, the rivet shaped by repeated blows to the set by a hammer, but from the early 20th century onwards a typical riveting gang would have used a hand-held pneumatic riveting gun. If you think of the tool Rosie the Riveter was often depicted as holding, you’re in the right place. However as the video below from 1949 shows, the scene would have otherwise changed little from the Victorian era, with the operator of a small forge tossing glowing rivets up to a worker who catches them in mid-air before placing them in the hole to be forged.

 

Swapping Rivets for Welders or Bolts

In 2018, you are only likely to encounter this type of iron rivet being used in heritage restoration work or in work that is intended to emulate it (The aviation industry uses rivets, but not quite the same as the ones you’d find in boilers or railway bridges!). Even then, as for example with the boiler on the new-build steam locomotive Tornado which was welded rather than riveted, it is by no means a given that rivets will be used. You can see a video of a modern-day riveting gang installing a boiler patch at LNWR Heritage in Crewe though, typical of this kind of riveting work. It’s ironic that even one of the most iconic riveters was pictured at a time when the practice was dying out, Rosie the Riveter’s portrait appeared while American shipyards were embracing the welder. Structural steel with mating holes is still used today, but high-strength bolts of a quality unavailable during the height of riveting have completely taken the place of rivets.

Speaking personally as a Hackaday scribe, my dad had occasional need to rivet as a blacksmith. Done by hand with the set positioned in the hardy hole of an anvil it was a more difficult job for an enthusiastic teen than you might expect, and I remember more than one attempt that emerged with distinct play in the resulting joint. I suspect I hadn’t managed to keep my rivet hot enough and thus its contraction had been less than it should have been. The rivets we were using were smaller than the ones in the videos after all. Perhaps if there had been handy online tutorials back in the day I’d have had more success.

Header image: Simon Lee [CC BY-SA 2.0].

Badgelife, The Hardware Demoscene Documentary

Last week, tens of thousands of people headed home from Vegas, fresh out of this year’s DEF CON. This was a great year for DEF CON, especially when it comes to hardware. This was the year independent badges took over, thanks to a small community of people dedicated to creating small-run hardware, puzzles, and PCB art for thousands of conference-goers. This is badgelife, a demoscene of hardware, and this is just the beginning. It’s only going to get bigger from here on out.

We were lucky enough to sit down with a few of the creators behind the badges of this year’s DEF CON and the interviews were fantastic. Right here is a lesson on electronic design, manufacturing, and logistics. If you’ve ever wanted to be an engineer that ships a product instead of a lowly maker that ships a product, this is the greatest classroom in the world.

Although badgelife may seem like a bunch of hardware engineers sitting behind a pick and place machine for a weekend’s worth of lulz, this is a masterclass of product design and manufacturing. Badgelife is product development, and unlike many other hardware design jobs, the ship date will not slip for any reason. The hardware must be done on time, and if you’re not shipping all the features you promised everyone will be upset. Badgelife is the best experience you’ll ever get in engineering for production, product design, and manufacturing.

The Greatest, and Most Coveted Badge

One of the most coveted badges at this year’s DEF CON was the one from AND!XOR. This team of engineers consisting of [zapp], [Hyr0n], [Bitstr3m], [8bit] and a few others have been creating independent badges for three years now. Their Bender badges are consistently held up as the example of what badgelife is all about: custom hardware turned into art on a tight production schedule. How do they do it? Effectively, they work backwards. Instead of throwing a microcontroller and some art on a board, they first figure out what they want the badge to do, and select their parts from there. The cost of prototyping, the number of expected failures, and the total cost of goods sold is all taken into account before the design is finalized. Only then do they make the prototypes and reach out to Kickstarter to fund the rest of the production run. This year was exceptional in that regard: AND!XOR sold 300 of their fantastic Bender badges overnight. Hundreds more were sold at the con.

The Official Badge

When it comes to manufacturing challenges, there’s no comparison to the main DEF CON badge. This year, the official badge was brought to life by a hardware collective known as Tymkrs. DEF CON reached out to the Tymkrs after seeing their incredible cubic badge from last year’s Cyphercon, and after months of work the Tymkrs managed to ship over 28,000 badges for this year’s DEF CON.

The theme for this year’s DEF CON, and this year’s DEF CON badge, is 1983, the year before the Orwellian hellscape of 1984. This is the year where it was still possible to change something, even though Oceania had always been at war with Eastasia. This idea gave the Tymkrs an idea for a game in the badge, where your choices affect those around you. This is done by ‘mating’ different badge together through a hermaphroditic connector. Plug two badges into each other, and it affects the status of each badge.

If there’s one problem with manufacturing 28,000 of something, it’s programming the microcontroller on every board. The best way to program thousands and thousands of chips is to have them programmed off the assembly line. For any DEF CON badge with a production timeline of a few months, there simply isn’t time for that. The next option is to have the chips programmed before they’re put on a reel. This is what the Tymkrs planned to do, but three weeks before the con their supplier reached out and told them they had no idea how to program these microcontrollers. Without a moment to spare, the Tymkrs said to ship them to the fab in China, asked the factory to hire some temp workers, and had dozens of people programming badges as they came out of a reflow oven. If you’re wondering how high someone’s blood pressure can go, just ask the Tymkrs.

No One Says You Need To Ship Thousands

The exquisite coin-op badge developed soley by badgemaker extraordinaire [Mike Szczys]But of course shipping a con’s worth of badges isn’t for everyone. Sometimes you don’t need to go big to make a huge impact on badgelife. Sometimes you only need to ship a few dozen units.

One of the stand-out badges of this year’s DEF CON was the Coin-Op badge from Hackaday Editor in Chief and Mister Hackaday himself, [Mike Szczys].

[Mike] has been involved in a number of badge projects before, from the 2017 Superconference ‘camera’ badge to the 2018 Belgrade retrocomputer badge, but he hasn’t gone deep and built a badge entirely by himself before. This changed with the Coin-Op badge, a badge inspired by the greatest video game ever, Galaga.

The design for the Coin-Op badge began on July 1st, and consisted of a Galaga ship-shaped board loaded up with LEDs and microcontrollers. [Mike] assembled almost sixty of these by hand in his basement by the end of the month, just in time for DEF CON. This was one of the great badges this year, and would have been in the running for the Badgelife contest if [Mike] wasn’t also tapped for his expertise as a badgelife contest judge. It just goes to show you don’t need to produce hundreds of badges — sometimes just a few dozen will make a huge impact.

It’s A Demoscene of Hardware

The rise of badgelife is one of the greatest advances in DIY hardware. This is the only place you’ll find people designing and manufacturing items on an extremely condensed time scale, all on their own. This is a demoscene of hardware, with dozens of groups showing off what they can do with limited resources and limited time. If the Commodore and Amiga demo shows are the top tier of software developers, badgelife is the Olympics for hardware engineers. This is it, and it’s only going to get better from here.

Installing LibreBoot the (Very) Lazy Way

Recently I was given a somewhat crusty looking ThinkPad T400 that seemed like it would make a good knock around machine to have on the bench, if it wasn’t for the fact the person who gave it to me had forgotten (or perhaps never knew) the BIOS password. Cleaning the machine up, putting more RAM in it, and swapping the wheezing hard drive for an SSD would be a relatively cheap way to wring a few more years of life from the machine, but not if I couldn’t change the boot order in BIOS.

Alright, that’s not entirely true. I could have installed an OS on the SSD from my desktop and then put it into the T400, but there was something else at play. The locked BIOS gave me the perfect excuse to install LibreBoot on it, which is one of those projects I’ve had in the back of my mind for years now. Replacing the BIOS with something entirely different would solve the password issue, but there was only one problem: the instructions for flashing LibreBoot onto the T400 are intimidating to say the least.

You’re supposed to take the entire machine apart, down to pulling the CPU cooler off and removing the display. All so you can flip the motherboard over to access a flash chip between the CPU and RAM that’s normally covered by a piece of the laptop’s frame. Oh how I hated that diabolical chunk of magnesium which kept me from my silicon quarry. Flashing the chip would take a few minutes, but YouTube videos and first hand accounts from forums told me it could take hours to disassemble the computer and then put it back together after the fact.

Deep into that darkness I peered, long I stood there, wondering, fearing, doubting. Then a thought came to me: maybe I could just cut the thing. If it was a success, it would save me hours of work. If it failed, well, at least the computer didn’t cost me anything. Time to roll the dice.

Risky Business

Cutting the frame instead of pulling the motherboard would be much faster, but did pose a few worrying problems. A major concern was the copious amounts of magnesium dust that taking a rotary tool to the frame would dump onto the motherboard. Granted magnesium isn’t a terribly great conductor, but it might still wreak havoc on the board if it worked its way into sensitive areas. The instructions also mentioned disconnecting all of the components from the board, which obviously I wouldn’t be doing either.

But above all, the biggest risk in this attempt would be the human element. There’s precious little space between the laptop’s frame and the motherboard itself, and the smallest mistake could gouge the PCB or destroy one of the components on it. If the cutting wheel even just taps anything beyond the frame itself, it could be game over.

Long story short, you shouldn’t go this route unless you can afford to lose the laptop if things don’t go well. If you have any strong feelings about this particular T400, or actually need to have a working machine after all is said and done, you might just want to spend the time to follow the official installation procedure.

Making the Cut

With a cutting wheel chucked up in the Dremel, the frame material gives way pretty quickly. I had to keep the speed fairly low and the pressure light, or else I was worried I’d blow right through it and dig into the motherboard. The metallic dust produced gets everywhere, and even if you’re normally too macho for eye protection, you’d be a fool not to use them for this. In fact, a dust mask would be a good idea as well.

The right hand cut is easy enough to make, and a relatively forgiving area to start with. I did end up digging into the plastic of the memory socket, but luckily it was one of the few things you can hit in there without doing any damage. On the left side, things get tricky. I was able to make a straight cut across the top of the chip with the wheel, but then had to widen the opening with a carbide burr to make enough room for the clip to attach.

Cleaning Up

After verifying I had enough clearance to get the clip on, I took the T400 outside and started hitting it with compressed air from as many angles as I could. I easily spent as much time blowing the magnesium dust out of every nook and cranny of the case as I did actually making the cuts. The process can be helped along by removing the optical and hard drive, as that will give you another opening to blow air through. Since there was really no way to tell when this phase of the process was done, I basically just keep going until my patience ran out.

While on the subject of shooting compressed air into electronics, I should mention my compressor has a coalescing filter on it to take moisture and oils out of the air before it reaches the blow gun. An unfiltered compressor can spray all sorts of atomized liquids and contaminates out, so you want to be very careful about the source of air you plan on using if you want to clean something like a motherboard.

Flashing LibreBoot

Our own Bryan Cockfield wrote up an illuminating first hand account about the highs and lows of flashing LibreBoot which is a must-read for anyone looking to take the plunge, so I won’t go over it all again here. Suffice it to say, the process isn’t exactly beginner friendly. From getting the programmer wired up to modifying the LibreBoot ROM file with your machine’s MAC address, it’s a path only to be walked by the true disciples of Saint IGNUcius.

That being said, the process went pretty smoothly. For my programmer I used a Raspberry Pi 3B+ and didn’t need an external power supply. I had a bit of trouble getting the clip attached onto the chip securely, but once it was on there tight enough that the flashrom tool could see it, it stayed connected until the process was complete.

The entire flash took just shy of 10 minutes with this setup, which compared to some of the horror stories I had read on forums, was a relief.

New Lease on Life

In the end, the process was a success. The T400 didn’t short out due to insidious magnesium particles (at least, not yet), and I was able to boot up to a USB flash drive to start the installation of Arch Linux. Start to finish it took a fraction of the time it would have to strip the machine down and build it back up. As for the experience of using LibreBoot itself, there’s definitely a learning curve. It still seems strange to me that there’s no configuration options anymore, the computer just boots directly into GRUB.

LibreBoot devotees will tell you that it increases performance and extends battery life, but I can’t speak to that because I never really used the computer before installing it. One thing I can tell you for certain is that if you’ve got a ThinkPad T400 with a locked BIOS, a Dremel, and nothing to lose, there is a light at the end of the tunnel.

Build a Fun CPU in Your Browser

A rite of passage for a digital designer is to build a CPU. That may seem a formidable task and if you are thinking of building a modern CPU like the one in your PC, it is. However, a simple CPU is well within the reach of anyone who can sling some logic gates or HDL. We’ve even seen CPUs built in Minecraft. Now you can play nandgame and build a CPU step-by-step in your browser.

The game is based on the popular From NAND to Tetris site. True to the name you start out with a single NAND gate as a tool. From there you build an inverter, an AND gate, adders, flip flops, registers, and the like. You get a little help from the accompanying text and there are some blacked out hints if you get stuck.

The site notes that it is not complete yet, and we presume it means there should be more explanatory text. By the time you are building the ALU and instruction units, the text is a little sparse. However, it is a great way to experiment with how a CPU works internally and it is sort of fun, too.

We only had one real complaint. There are a few things that are made unnecessarily difficult because there is no way to get a solid logic 1 or 0 into the design — something that would not be true in real life. In addition, the feedback loops used to build flip flops isn’t very practical either, but at least it doesn’t make the game more difficult than real life. But it would be nice if they noted that in real life you’d have trouble doing as they suggest.

A lot of the custom CPUs we’ve seen on FPGAs are just toys. But two come to mind that are not. [Robert Baruch] has a custom CPU that can play Zork. We were very impressed with [F4HDK’s] A2Z computer which not only sports a powerful custom CPU, but also has an OS, a file system, and a set of utilities.

Older posts are this way If this message doesn't go away, click anywhere on the page to continue loading posts.
Could not load more posts
Maybe Soup is currently being updated? I'll try again automatically in a few seconds...
Just a second, loading more posts...
You've reached the end.

Don't be the product, buy the product!

Schweinderl